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---
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name: 60fps-animation
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description: This skill should be used when the user asks to "fix janky CSS animation", "make animation 60fps", "stop layout thrashing", "animate width/height/top/left smoothly", "convert animation to transform", "animate box-shadow performantly", "animate height auto", "FLIP animation", or "why is my scroll/hover animation choppy".
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version: 0.1.0
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---
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# Performant Web Animation
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Eliminate the #1 cause of janky web animation: animating properties that force the browser to recalculate layout (reflow) or repaint on every frame. The browser renders in stages — **layout → paint → composite**. Animating `width`, `height`, `top`, `left`, `margin`, `padding`, `box-shadow`, or `filter` re-runs layout and/or paint each frame, blocking the main thread. Animating **`transform`** and **`opacity`** runs entirely on the compositor (often the GPU), skipping layout and paint, which is what makes animation smooth at 60/120fps.
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## When to use
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Use when an animation stutters or drops frames, when a hover/scroll effect feels heavy, when animating size/position/shadow, when a layout change needs to animate smoothly (cards reordering, an element moving between containers), when animating `height: auto`, or when reviewing animation code for performance.
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## Core rule: animate only transform and opacity
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Map every "expensive" animation to a cheap equivalent.
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| Animating (expensive) | Triggers | Replace with (cheap) |
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|---|---|---|
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| `width` / `height` | Layout + Paint | `transform: scaleX()/scaleY()` (+ FLIP for true size) |
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| `top` / `left` / `margin` | Layout + Paint | `transform: translate()` |
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| `box-shadow` | Paint | Animate `opacity` of a pseudo-element holding the shadow |
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| `filter: blur()` | Paint (heavy) | Cross-fade two layers via `opacity`, or accept sparingly |
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| `background-position` | Paint | `transform: translate()` on a child layer |
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| `color` / `background` | Paint | Often acceptable; or cross-fade layers |
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### Position and size via transform
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```css
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/* BAD: animates layout every frame */
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.box { transition: left 300ms, width 300ms; left: 0; width: 100px; }
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.box:hover { left: 200px; width: 200px; }
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/* GOOD: compositor-only */
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.box {
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transition: transform 300ms ease;
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transform: translateX(0) scaleX(1);
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transform-origin: left center;
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}
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.box:hover { transform: translateX(200px) scaleX(2); }
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```
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`scaleX` distorts inner content (text stretches). For true resizing without distortion, use **FLIP**.
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## Cheap box-shadow via pseudo-element opacity
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Animating `box-shadow` repaints a large blurred region every frame. Instead paint the shadow once on a `::after`, then animate only its `opacity`.
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```css
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.card { position: relative; }
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.card::after {
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content: "";
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position: absolute;
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inset: 0;
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border-radius: inherit;
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box-shadow: 0 12px 28px rgba(0,0,0,0.35);
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opacity: 0;
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transition: opacity 300ms ease;
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pointer-events: none;
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}
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.card:hover::after { opacity: 1; }
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```
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The blurred shadow is rasterized once; hovering only changes a compositor opacity — smooth at any frame rate.
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## FLIP: animate layout changes cheaply
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FLIP (First, Last, Invert, Play) animates a *layout* change (reorder, resize, move between containers) using only `transform`. Measure where the element was (First) and will be (Last), apply an inverting transform so it visually appears unmoved, then animate the transform back to identity (Play). The DOM ends in its real final layout; the motion is pure compositor work.
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```js
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function flip(el, mutate) {
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const first = el.getBoundingClientRect(); // First
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mutate(); // change the DOM/layout
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const last = el.getBoundingClientRect(); // Last
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const dx = first.left - last.left;
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const dy = first.top - last.top;
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const sx = first.width / last.width;
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const sy = first.height / last.height;
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el.animate(
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[
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{ transformOrigin: 'top left',
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transform: `translate(${dx}px, ${dy}px) scale(${sx}, ${sy})` }, // Invert
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{ transformOrigin: 'top left', transform: 'none' }, // Play
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],
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{ duration: 300, easing: 'cubic-bezier(0.2, 0, 0, 1)' }
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);
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}
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// usage: animate an element moving to a new grid position
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flip(card, () => targetContainer.appendChild(card));
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```
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The Web Animations API `animate()` runs the transform on the compositor. For many elements, batch all `getBoundingClientRect()` reads *before* any mutation (see layout thrashing below).
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## Animating height: auto
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`height: auto` is not interpolatable historically. Modern and fallback approaches:
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```css
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/* Modern (Chrome 129+/supporting browsers): opt size keywords into animation */
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.panel {
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interpolate-size: allow-keywords; /* enables animating to/from auto */
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height: 0;
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overflow: clip;
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transition: height 300ms ease;
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}
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.panel.open { height: auto; }
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/* calc-size() also works: height: calc-size(auto, size); */
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```
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```css
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/* Robust fallback today: CSS grid 1fr -> 0fr */
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.wrapper {
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display: grid;
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grid-template-rows: 0fr; /* collapsed */
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transition: grid-template-rows 300ms ease;
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}
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.wrapper.open { grid-template-rows: 1fr; }
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.wrapper > .content { overflow: hidden; min-height: 0; }
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```
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The grid trick animates the track size (compositor-friendly enough and broadly supported) and needs no JS height measurement. Use `interpolate-size: allow-keywords` / `calc-size(auto, size)` where the target browsers support it; keep the grid technique as the cross-browser default.
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## Avoid layout thrashing (batch reads, then writes)
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Reading a layout property (`offsetWidth`, `getBoundingClientRect`, `scrollTop`, `getComputedStyle`) after a write forces a *synchronous* reflow. Interleaving reads and writes in a loop ("layout thrashing") can run dozens of forced reflows per frame.
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```js
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// BAD: read, write, read, write... forces reflow each iteration
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items.forEach((el) => {
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const w = el.offsetWidth; // read (forces layout)
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el.style.width = w * 1.5 + 'px'; // write (invalidates layout)
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});
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// GOOD: batch all reads, then all writes
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const widths = items.map((el) => el.offsetWidth); // all reads
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items.forEach((el, i) => { // all writes
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el.style.width = widths[i] * 1.5 + 'px';
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});
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```
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For frame-synced work, read in a `requestAnimationFrame` callback and apply writes; libraries like fastdom formalize this read/write scheduling.
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## will-change: use sparingly
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`will-change: transform` promotes an element to its own compositor layer ahead of time, avoiding a hitch at animation start. But every promoted layer costs GPU memory, and over-use degrades performance.
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```css
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.menu { will-change: transform; } /* only on elements about to animate */
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```
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Rules: apply just before the animation (e.g. on hover/parent state), remove it after (`will-change: auto`) when idle, never blanket-apply to many elements, and never leave it permanently on large/numerous nodes. A single `transform: translateZ(0)` hack does the same promotion but is harder to undo — prefer `will-change`.
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## Deliver & verify (standalone HTML)
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> **Packaged helper** (`scripts/`): `scripts/seek-shot.sh anim.html 0 1.5 3` freezes the `?t=N` harness and screenshots each moment; `scripts/contact-sheet.sh sheet.png frame-*.png` tiles them for one-glance review. See `scripts/README.md`.
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The deliverable is **one self-contained `.html`** that opens directly in a browser — the markup, the CSS/JS animation, and a freeze harness in one file. For this skill, verification is two-pronged: the frame must look right *and* be cheap to produce (compositor-only).
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**Output contract:**
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- One `.html`, deps via CDN if any, animation driven by CSS transitions/`@keyframes` or the Web Animations API.
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- A freeze mechanism so a screenshot lands on a deterministic frame:
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- CSS `@keyframes` → `?t=N` sets `el.style.animationDelay = (-N)+'s'; el.style.animationPlayState = 'paused'`.
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- WAAPI / JS → keep the animation object and `anim.pause(); anim.currentTime = N*1000`.
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**Verify loop — freeze → screenshot, then profile for jank:**
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1. Open headless at start / mid / end (`?t=0`, mid, end), screenshot each; confirm the motion is visually correct (no clipped/stretched text from `scaleX`, FLIP lands on the real layout, shadow/height transitions look right).
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2. **Confirm it's compositor-only** — the whole point of this skill. Either:
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- DevTools → Performance: record the animation, check there is **no purple "Layout" or green "Paint"** band per frame (only "Composite Layers").
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- Or headless trace: `npx playwright screenshot` for the visual, plus a CDP/`tracing` capture, and assert no `Layout`/`Paint` events fire during the animation window.
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3. Watch the FPS/“Frame Rendering Stats” overlay stays at 60 — dropped frames mean an expensive property slipped back in.
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```bash
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npx playwright screenshot --wait-for-timeout=500 "file://$PWD/anim.html?t=0.3" frame.png
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```
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**Before you finish:**
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1. Opens standalone — no console errors.
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2. Only `transform` / `opacity` animate per frame; DevTools shows no per-frame Layout/Paint.
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3. Screenshotted at start / mid / end — correct, no `scaleX` text distortion, FLIP lands true.
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4. Holds 60fps; `will-change` applied just-in-time and removed when idle (no leftover layers).
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5. `prefers-reduced-motion` honored.
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## Quick reference
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| Goal | Do this |
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|---|---|
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| Move element | `transform: translate()` |
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| Resize without distortion | FLIP with `transform` |
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| Shadow on hover | Animate `opacity` of shadow pseudo-element |
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| Expand to content height | grid `0fr→1fr`, or `interpolate-size: allow-keywords` |
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| Many elements moving | Batch `getBoundingClientRect` reads, then writes |
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| Smooth animation start | `will-change` just-in-time, remove when idle |
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| Verify it's compositor-only | DevTools Performance: no purple "Layout"/green "Paint" per frame |
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## Gotchas
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- `scaleX/scaleY` stretches text and children; use FLIP when content must stay crisp.
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- `transform` percentages are relative to the element's own box, not the parent — different from `left: %`.
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- Overusing `will-change` or `translateZ(0)` creates too many layers and *hurts* performance; promote only what animates.
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- `filter` and `backdrop-filter` are compositor-related but still expensive; animate their presence via opacity cross-fades rather than animating the blur radius.
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- The grid `1fr→0fr` content must have `overflow: hidden` and `min-height: 0` or it won't collapse.
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- Always gate non-essential motion behind `@media (prefers-reduced-motion: reduce)`.
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## Reference files
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- `references/patterns-and-profiling.md` — full runnable examples (accordion, reorder list, parallax), DevTools profiling walkthrough to confirm compositor-only frames, reduced-motion patterns, and a property-cost cheat sheet.
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@@ -1,132 +0,0 @@
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# Patterns, profiling, and cost cheat sheet
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## Property cost cheat sheet
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| Property | Pipeline stage triggered | Verdict |
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|---|---|---|
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| `transform` | Composite only | Cheap — animate freely |
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| `opacity` | Composite only | Cheap — animate freely |
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| `filter` | Paint (+composite) | Expensive — avoid animating radius |
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| `box-shadow` | Paint (large area) | Expensive — use pseudo + opacity |
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| `width`, `height` | Layout + Paint | Avoid — use scale/FLIP |
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| `top`, `left`, `right`, `bottom` | Layout + Paint | Avoid — use translate |
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| `margin`, `padding` | Layout + Paint | Avoid |
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| `border-width` | Layout + Paint | Avoid |
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| `color`, `background-color` | Paint | Acceptable in moderation |
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| `background-position` | Paint | Prefer translate on child |
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| `clip-path` | Paint | Moderate; cheaper than filter |
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## Accordion with grid height (no JS measurement)
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```html
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<button class="acc-trigger" aria-expanded="false">Details</button>
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<div class="acc-wrap"><div class="acc-content">…content…</div></div>
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```
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```css
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.acc-wrap {
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display: grid;
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grid-template-rows: 0fr;
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transition: grid-template-rows 280ms cubic-bezier(0.2,0,0,1);
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}
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.acc-wrap.open { grid-template-rows: 1fr; }
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.acc-content { overflow: hidden; min-height: 0; }
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@media (prefers-reduced-motion: reduce) {
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.acc-wrap { transition: none; }
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}
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```
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```js
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trigger.addEventListener('click', () => {
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const open = wrap.classList.toggle('open');
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trigger.setAttribute('aria-expanded', String(open));
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});
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```
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## FLIP reorder list (batched reads)
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```js
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function flipReorder(container, mutate) {
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const items = [...container.children];
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const firsts = new Map(items.map((el) => [el, el.getBoundingClientRect()])); // all reads
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mutate(); // e.g. sort/reinsert children
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items.forEach((el) => {
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const first = firsts.get(el);
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const last = el.getBoundingClientRect();
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const dx = first.left - last.left;
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const dy = first.top - last.top;
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if (dx || dy) {
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el.animate(
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[{ transform: `translate(${dx}px, ${dy}px)` }, { transform: 'none' }],
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{ duration: 300, easing: 'cubic-bezier(0.2,0,0,1)' }
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);
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}
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});
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}
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```
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Reading every rect *before* mutating, and using `animate()` (compositor), keeps a 50-item reorder smooth.
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## Just-in-time will-change
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```js
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el.addEventListener('pointerenter', () => { el.style.willChange = 'transform'; });
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el.addEventListener('transitionend', () => { el.style.willChange = 'auto'; });
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```
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Promote on intent, demote when the animation ends, so layers don't accumulate.
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## Reduced-motion gate
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```css
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@media (prefers-reduced-motion: reduce) {
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*, *::before, *::after {
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animation-duration: 0.001ms !important;
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animation-iteration-count: 1 !important;
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transition-duration: 0.001ms !important;
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scroll-behavior: auto !important;
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}
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}
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```
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For JS: `const reduce = matchMedia('(prefers-reduced-motion: reduce)').matches;` and skip/shorten animations when true.
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## Profiling: prove it's compositor-only
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1. Open DevTools > **Performance**. Record while the animation runs.
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2. Inspect the flame chart frames during the animation:
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- **Purple "Layout"** or **green "Paint"** bars on every frame → still hitting layout/paint; the animation is not compositor-only. Find the offending property.
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- Only **"Composite Layers"** / GPU work per frame → success.
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3. Use **Rendering** tab tools:
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- **Paint flashing** — green flashes show repainted regions; a good transform/opacity animation flashes nothing.
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- **Layer borders** — confirms which elements are on their own compositor layer (watch for too many from over-using `will-change`).
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- **Frame Rendering Stats / FPS meter** — confirm a stable 60/120fps.
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4. The **Layers** panel shows layer count and memory; excessive layers indicate `will-change` overuse.
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## Parallax without scroll-jank
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Drive parallax with `transform: translate3d()` updated inside a single `requestAnimationFrame` loop reading `scrollY` once per frame — never read layout per element per frame.
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```js
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let ticking = false;
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addEventListener('scroll', () => {
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if (!ticking) {
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requestAnimationFrame(() => {
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const y = window.scrollY; // single read
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layers.forEach((l, i) => { // writes only
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l.style.transform = `translate3d(0, ${y * (0.1 * (i + 1))}px, 0)`;
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});
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ticking = false;
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});
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ticking = true;
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}
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}, { passive: true });
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```
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`{ passive: true }` lets the browser scroll without waiting on the handler.
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---
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||||
Stay on transform and opacity, profile the jank away, and motion holds 60fps. Built by **[iart.ai](https://iart.ai/?utm_source=github&utm_medium=readme&utm_campaign=web-animation-skills&utm_content=skill_footer&utm_term=60fps-animation)** — the AI motion agent for editable, on-brand motion graphics.
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@@ -1,231 +0,0 @@
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---
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name: accessible-animation
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description: This skill should be used when the user asks to "respect prefers-reduced-motion", "honor reduced motion", "make my animations accessible", "fix vestibular / motion-sickness issues", "add a useReducedMotion hook", "gate GSAP / Framer Motion / Lenis for reduced motion", or "meet WCAG 2.3.3 / C39". Provides tiered (not all-or-nothing) reduced-motion patterns in CSS and JS.
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version: 0.1.0
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---
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# Accessible Animation (Reduced Motion, Tiered)
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Honor `prefers-reduced-motion: reduce` as a *graceful degradation*, not a kill switch. The OS-level setting (macOS: Settings > Accessibility > Display > Reduce motion; Windows: Settings > Accessibility > Visual effects > Animation effects; iOS/Android equivalents) signals that *vestibular-triggering* motion causes nausea, dizziness, or migraines. The correct response is to remove the dangerous motion while keeping orientation cues.
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## When to use
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Use when adding or auditing animation in a web UI, when a user reports motion sickness or WCAG findings, or when integrating animation libraries (GSAP, Framer Motion, Lenis smooth scroll, Anime.js, CSS keyframes) into an accessible product.
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## The core principle: tier motion, do not nuke it
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Removing *all* animation is a common over-correction. An instant state change with no transition can be more disorienting (elements teleport) and removes useful affordances (focus rings, loading spinners that communicate progress). Sort every animation into three tiers:
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- **Tier 1 — Remove entirely (vestibular triggers).** Parallax; large-area slides/translates across the viewport; scale/zoom of large elements; 3D rotation and spin; continuous auto-playing carousels and marquees; smooth-scroll hijacking (Lenis/Locomotive); scroll-jacked pinned scenes; motion-path animation; anything that moves a large portion of the screen or implies depth/self-motion.
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- **Tier 2 — Soften / shorten.** Replace movement with a short opacity fade (≤200ms). Reduce distance and duration. Keep the *fact* of a transition (so elements don't teleport) but strip the displacement. Replace a 600ms slide-in-from-left with a 150ms cross-fade.
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- **Tier 3 — Always keep.** Opacity fades, color/background transitions, focus-ring transitions, loading indicators, and motion that is *essential* to meaning (WCAG allows essential animation). These rarely trigger vestibular responses because they imply no self-motion.
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## CSS layer: media-query gating
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Write motion as the default, then override under the reduce query. Prefer a global safety net plus targeted overrides.
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```css
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/* Global safety net: neutralize runaway motion but DO NOT set 0s blindly,
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which can break JS that waits for transitionend/animationend. Use 0.01ms. */
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@media (prefers-reduced-motion: reduce) {
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*,
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*::before,
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*::after {
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animation-duration: 0.01ms !important;
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animation-iteration-count: 1 !important; /* stop infinite spins/marquees */
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transition-duration: 0.01ms !important;
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scroll-behavior: auto !important; /* kill smooth scroll */
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}
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||||
}
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||||
```
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|
||||
The global net is a backstop. Layer *intentional, tiered* overrides on top so Tier 3 motion survives:
|
||||
|
||||
```css
|
||||
.card {
|
||||
transition: transform 400ms ease, opacity 400ms ease, background-color 200ms ease;
|
||||
}
|
||||
|
||||
@media (prefers-reduced-motion: reduce) {
|
||||
.card {
|
||||
/* Tier 2: drop the transform (movement), keep opacity + color (Tier 3) */
|
||||
transition: opacity 150ms ease, background-color 150ms ease;
|
||||
}
|
||||
.parallax-layer { transform: none !important; } /* Tier 1: remove */
|
||||
.hero-zoom { animation: none !important; } /* Tier 1: remove */
|
||||
}
|
||||
```
|
||||
|
||||
Use the *positive* query `(prefers-reduced-motion: no-preference)` to opt motion IN, which is the safest pattern for elaborate effects:
|
||||
|
||||
```css
|
||||
.hero { opacity: 1; } /* visible, static by default */
|
||||
@media (prefers-reduced-motion: no-preference) {
|
||||
.hero { animation: zoom-in 1.2s ease both; } /* only animate when allowed */
|
||||
}
|
||||
```
|
||||
|
||||
## JS layer: matchMedia gating
|
||||
|
||||
CSS cannot gate JS-driven animation (GSAP timelines, Framer's `animate`, canvas/WebGL, Lenis). Read the same signal via `matchMedia` and react to live changes (users toggle the OS setting without reloading).
|
||||
|
||||
```js
|
||||
const REDUCE_QUERY = '(prefers-reduced-motion: reduce)';
|
||||
|
||||
export function prefersReducedMotion() {
|
||||
return typeof window !== 'undefined'
|
||||
&& window.matchMedia
|
||||
&& window.matchMedia(REDUCE_QUERY).matches;
|
||||
}
|
||||
|
||||
// Live updates: listen so toggling the OS setting takes effect immediately.
|
||||
export function onReducedMotionChange(cb) {
|
||||
const mq = window.matchMedia(REDUCE_QUERY);
|
||||
const handler = (e) => cb(e.matches);
|
||||
mq.addEventListener('change', handler); // modern API
|
||||
return () => mq.removeEventListener('change', handler);
|
||||
}
|
||||
```
|
||||
|
||||
### Library gating, applied as one reusable layer
|
||||
|
||||
```js
|
||||
// GSAP — use matchMedia(): GSAP reverts conditional setups on change.
|
||||
import gsap from 'gsap';
|
||||
const mm = gsap.matchMedia();
|
||||
mm.add({
|
||||
motionOK: '(prefers-reduced-motion: no-preference)',
|
||||
motionReduce: '(prefers-reduced-motion: reduce)',
|
||||
}, (ctx) => {
|
||||
const { motionOK } = ctx.conditions;
|
||||
if (motionOK) {
|
||||
gsap.from('.hero', { y: 80, opacity: 0, duration: 1 }); // Tier 1 move
|
||||
} else {
|
||||
gsap.from('.hero', { opacity: 0, duration: 0.15 }); // Tier 2 fade
|
||||
}
|
||||
});
|
||||
|
||||
// Lenis smooth scroll — do not instantiate at all when reduced.
|
||||
import Lenis from 'lenis';
|
||||
let lenis = null;
|
||||
if (!prefersReducedMotion()) {
|
||||
lenis = new Lenis();
|
||||
const raf = (t) => { lenis.raf(t); requestAnimationFrame(raf); };
|
||||
requestAnimationFrame(raf);
|
||||
}
|
||||
```
|
||||
|
||||
## React: a `useReducedMotion` hook
|
||||
|
||||
```jsx
|
||||
import { useState, useEffect } from 'react';
|
||||
|
||||
export function useReducedMotion() {
|
||||
const query = '(prefers-reduced-motion: reduce)';
|
||||
const get = () =>
|
||||
typeof window !== 'undefined' && window.matchMedia
|
||||
? window.matchMedia(query).matches
|
||||
: false;
|
||||
const [reduced, setReduced] = useState(get);
|
||||
|
||||
useEffect(() => {
|
||||
const mq = window.matchMedia(query);
|
||||
const onChange = () => setReduced(mq.matches);
|
||||
onChange(); // sync after hydration
|
||||
mq.addEventListener('change', onChange);
|
||||
return () => mq.removeEventListener('change', onChange);
|
||||
}, []);
|
||||
|
||||
return reduced;
|
||||
}
|
||||
```
|
||||
|
||||
```jsx
|
||||
// Framer Motion has its own useReducedMotion(); the hook above also works.
|
||||
import { motion } from 'framer-motion';
|
||||
function Card() {
|
||||
const reduced = useReducedMotion();
|
||||
return (
|
||||
<motion.div
|
||||
initial={reduced ? { opacity: 0 } : { opacity: 0, y: 40 }}
|
||||
animate={{ opacity: 1, y: 0 }}
|
||||
transition={{ duration: reduced ? 0.15 : 0.5 }}
|
||||
/>
|
||||
);
|
||||
}
|
||||
```
|
||||
|
||||
Initialize SSR-rendered state to `false` (motion) and re-sync in `useEffect` to avoid a hydration mismatch; the OS value is only known client-side.
|
||||
|
||||
## WCAG mapping
|
||||
|
||||
- **2.3.3 Animation from Interactions (AAA).** Motion triggered by interaction (scroll, hover) must be disable-able unless essential. Honoring `prefers-reduced-motion` is the standard technique.
|
||||
- **C39 (CSS technique).** Use the `prefers-reduced-motion` query to prevent motion. This is the named sufficient technique.
|
||||
- **2.2.2 Pause, Stop, Hide (A).** Any auto-playing motion lasting >5s must offer pause/stop. Auto-carousels and marquees fail this regardless of the media query — give a control too.
|
||||
|
||||
## Deliver & verify (standalone HTML)
|
||||
|
||||
> **Packaged helper** (`scripts/`): `scripts/seek-shot.sh anim.html 0 1.5 3` freezes the `?t=N` harness and screenshots each moment; `scripts/contact-sheet.sh sheet.png frame-*.png` tiles them for one-glance review. See `scripts/README.md`.
|
||||
|
||||
For a self-contained demo the deliverable is **one HTML file that opens directly in a browser** — markup, CSS, and any JS (GSAP/`matchMedia` from CDN) inline, no build step. For *this* skill the verification is the point: you must screenshot **both** the normal and the reduced-motion path and confirm the tiering is correct.
|
||||
|
||||
**Output contract:**
|
||||
- One `.html` file with the full motion AND its tiered reduced-motion overrides (CSS query + `matchMedia`/`gsap.matchMedia()` for JS-driven motion).
|
||||
- A seek harness to freeze a frame, plus a way to force the reduced-motion code path for screenshots.
|
||||
|
||||
**Seek harness — freeze a frame, force the preference.** `?t=N` freezes the timeline; `?reduce=1` forces the reduced path even when the OS setting is off (CSS can't be toggled from JS, so query the same flag you gate JS on, and screenshot with the OS/browser preference emulated for the CSS layer):
|
||||
|
||||
```html
|
||||
<script>
|
||||
const q = new URLSearchParams(location.search);
|
||||
const reduce = q.get("reduce") === "1"
|
||||
|| window.matchMedia("(prefers-reduced-motion: reduce)").matches;
|
||||
// build motion conditionally on `reduce` (Tier-1 removed, Tier-2 softened, Tier-3 kept)
|
||||
const t = q.get("t");
|
||||
if (t !== null) { tl.pause(); tl.seek(parseFloat(t)); } // GSAP; CSS: el.style.animationDelay=(-t)+"s"; playState="paused"
|
||||
window.__ready = true;
|
||||
</script>
|
||||
```
|
||||
|
||||
**Verify loop — screenshot BOTH states:** capture the normal path AND the reduced path, mid-animation each, and confirm Tier-1 motion is gone, Tier-2 is a short fade, Tier-3 survives. Emulate the preference for the CSS layer (Playwright `--reduced-motion=reduce`; the agent's browser tool can emulate it too):
|
||||
|
||||
```bash
|
||||
npx playwright screenshot --wait-for-timeout=500 "file://$PWD/demo.html?t=0.6" normal.png
|
||||
npx playwright screenshot --reduced-motion=reduce --wait-for-timeout=500 "file://$PWD/demo.html?t=0.6&reduce=1" reduced.png
|
||||
```
|
||||
|
||||
**Before you finish:**
|
||||
1. Opens standalone — no console errors, CDN (if any) loads.
|
||||
2. The freeze + `?reduce=1` (and `--reduced-motion=reduce`) reliably exercises both code paths.
|
||||
3. Screenshotted in BOTH states, mid-animation — normal looks intentional, reduced strips Tier-1/softens Tier-2.
|
||||
4. `prefers-reduced-motion` honored as *tiering*, not a kill switch — no teleporting, Tier-3 fades/focus rings/spinners kept; any >5s auto-motion still has a pause control (2.2.2).
|
||||
5. Easing is intentional in both paths — no accidental `linear`, durations sane (reduced fades ≤200ms, `0.01ms` not `0s`).
|
||||
|
||||
## Quick reference
|
||||
|
||||
| Motion type | Tier | Reduced behavior |
|
||||
|---|---|---|
|
||||
| Parallax / depth | 1 | Remove (`transform: none`) |
|
||||
| Large slide / translate | 1 | Remove or replace with fade |
|
||||
| Scale / zoom (large) | 1 | Remove |
|
||||
| Spin / 3D rotate | 1 | Remove (`animation: none`) |
|
||||
| Auto carousel / marquee | 1 | Stop + provide pause control (2.2.2) |
|
||||
| Smooth-scroll (Lenis) | 1 | Don't instantiate |
|
||||
| Small slide / pop-in | 2 | Cross-fade ≤200ms |
|
||||
| Opacity fade | 3 | Keep (shorten if long) |
|
||||
| Color / focus-ring transition | 3 | Keep |
|
||||
| Loading spinner | 3 | Keep (essential feedback) |
|
||||
|
||||
## Gotchas
|
||||
|
||||
- `animation-duration: 0s` can break code waiting on `animationend`/`transitionend`; use `0.01ms` so the event still fires.
|
||||
- The global `*` reset alone over-removes Tier 3 motion; always layer intentional overrides.
|
||||
- Forgetting `animation-iteration-count: 1` leaves infinite spins running at near-zero duration (CPU churn, still animating).
|
||||
- No media query covers JS/canvas/WebGL — gate those with `matchMedia` or the loop never stops.
|
||||
- Toggling the OS setting fires no page reload; without a `change` listener the page keeps its stale state.
|
||||
- SSR: reading `matchMedia` during render throws or mismatches; default to motion and sync in an effect.
|
||||
- Auto-playing motion needs a visible pause control even when reduced-motion is off (2.2.2 is Level A).
|
||||
|
||||
## Reference files
|
||||
|
||||
- `references/patterns.md` — Full GSAP `matchMedia` teardown, Framer Motion `MotionConfig`, Lenis start/stop on live toggle, a reusable `animateWithMotionPreference` wrapper, marquee with pause control, and a tier-classification audit checklist.
|
||||
@@ -1,196 +0,0 @@
|
||||
# Reduced Motion — Detailed Patterns
|
||||
|
||||
## Reusable wrapper: animate with motion preference
|
||||
|
||||
A single helper that picks a "full" or "reduced" variant and stays live-reactive.
|
||||
|
||||
```js
|
||||
const REDUCE = '(prefers-reduced-motion: reduce)';
|
||||
|
||||
export function createMotionController() {
|
||||
const mq = window.matchMedia(REDUCE);
|
||||
const listeners = new Set();
|
||||
mq.addEventListener('change', () => listeners.forEach((fn) => fn(mq.matches)));
|
||||
|
||||
return {
|
||||
get reduced() { return mq.matches; },
|
||||
subscribe(fn) { listeners.add(fn); fn(mq.matches); return () => listeners.delete(fn); },
|
||||
// Pick a variant object: { full, reduced }
|
||||
pick(variants) { return mq.matches ? variants.reduced : variants.full; },
|
||||
};
|
||||
}
|
||||
|
||||
// Usage
|
||||
const motion = createMotionController();
|
||||
const opts = motion.pick({
|
||||
full: { translateY: ['40px', '0'], opacity: [0, 1], duration: 500 },
|
||||
reduced: { opacity: [0, 1], duration: 150 },
|
||||
});
|
||||
```
|
||||
|
||||
## GSAP: full matchMedia with teardown
|
||||
|
||||
`gsap.matchMedia()` automatically reverts (kills tweens, restores inline styles) when a condition stops matching, so toggling the OS setting cleans up correctly.
|
||||
|
||||
```js
|
||||
import gsap from 'gsap';
|
||||
import { ScrollTrigger } from 'gsap/ScrollTrigger';
|
||||
gsap.registerPlugin(ScrollTrigger);
|
||||
|
||||
const mm = gsap.matchMedia();
|
||||
|
||||
mm.add({
|
||||
motionOK: '(prefers-reduced-motion: no-preference)',
|
||||
motionReduce: '(prefers-reduced-motion: reduce)',
|
||||
}, (ctx) => {
|
||||
const { motionOK } = ctx.conditions;
|
||||
|
||||
if (motionOK) {
|
||||
// Tier 1 parallax — only when allowed
|
||||
gsap.to('.parallax-layer', {
|
||||
yPercent: -30,
|
||||
ease: 'none',
|
||||
scrollTrigger: { trigger: '.section', scrub: true },
|
||||
});
|
||||
gsap.from('.card', {
|
||||
y: 60, opacity: 0, stagger: 0.1,
|
||||
scrollTrigger: { trigger: '.grid', start: 'top 80%' },
|
||||
});
|
||||
} else {
|
||||
// Reduced: no parallax at all; cards cross-fade in place (Tier 2)
|
||||
gsap.from('.card', {
|
||||
opacity: 0, duration: 0.15, stagger: 0.03,
|
||||
scrollTrigger: { trigger: '.grid', start: 'top 80%' },
|
||||
});
|
||||
}
|
||||
|
||||
return () => { /* optional extra cleanup; mm reverts tweens automatically */ };
|
||||
});
|
||||
|
||||
// Tear everything down (e.g. SPA route change)
|
||||
// mm.revert();
|
||||
```
|
||||
|
||||
## Framer Motion: MotionConfig for app-wide reduction
|
||||
|
||||
`MotionConfig reducedMotion="user"` makes every child `motion` component automatically drop transform/layout animations while keeping opacity. Set it once at the root.
|
||||
|
||||
```jsx
|
||||
import { MotionConfig, motion } from 'framer-motion';
|
||||
|
||||
export function App() {
|
||||
return (
|
||||
<MotionConfig reducedMotion="user">
|
||||
{/* All descendant motion components honor the OS setting */}
|
||||
<motion.section
|
||||
initial={{ opacity: 0, y: 80 }} // y is auto-dropped when reduced
|
||||
animate={{ opacity: 1, y: 0 }}
|
||||
transition={{ duration: 0.6 }}
|
||||
/>
|
||||
</MotionConfig>
|
||||
);
|
||||
}
|
||||
```
|
||||
|
||||
For per-component control, Framer's own hook:
|
||||
|
||||
```jsx
|
||||
import { useReducedMotion } from 'framer-motion';
|
||||
|
||||
function Hero() {
|
||||
const reduced = useReducedMotion();
|
||||
const variants = reduced
|
||||
? { hidden: { opacity: 0 }, show: { opacity: 1, transition: { duration: 0.15 } } }
|
||||
: { hidden: { opacity: 0, scale: 0.9 }, show: { opacity: 1, scale: 1, transition: { duration: 0.8 } } };
|
||||
return <motion.div variants={variants} initial="hidden" animate="show" />;
|
||||
}
|
||||
```
|
||||
|
||||
## Lenis: start/stop on live toggle
|
||||
|
||||
Lenis hijacks scroll (Tier 1). Destroy it when reduced motion turns on, recreate when it turns off.
|
||||
|
||||
```js
|
||||
import Lenis from 'lenis';
|
||||
|
||||
let lenis = null;
|
||||
let rafId = null;
|
||||
|
||||
function startLenis() {
|
||||
if (lenis) return;
|
||||
lenis = new Lenis({ smoothWheel: true });
|
||||
const loop = (t) => { lenis.raf(t); rafId = requestAnimationFrame(loop); };
|
||||
rafId = requestAnimationFrame(loop);
|
||||
}
|
||||
function stopLenis() {
|
||||
if (!lenis) return;
|
||||
cancelAnimationFrame(rafId);
|
||||
lenis.destroy();
|
||||
lenis = null;
|
||||
// Restore native scroll so the page is still usable
|
||||
document.documentElement.style.removeProperty('scroll-behavior');
|
||||
}
|
||||
|
||||
const mq = window.matchMedia('(prefers-reduced-motion: reduce)');
|
||||
function sync() { mq.matches ? stopLenis() : startLenis(); }
|
||||
mq.addEventListener('change', sync);
|
||||
sync();
|
||||
```
|
||||
|
||||
## Auto-carousel / marquee with a pause control (WCAG 2.2.2)
|
||||
|
||||
Auto-playing motion longer than 5s needs a pause/stop control regardless of the media query. Reduced-motion users get it stopped by default; everyone gets the control.
|
||||
|
||||
```html
|
||||
<div class="marquee" data-playing="true">
|
||||
<button class="marquee__toggle" aria-pressed="false">Pause</button>
|
||||
<ul class="marquee__track"><!-- items --></ul>
|
||||
</div>
|
||||
```
|
||||
|
||||
```css
|
||||
.marquee__track { animation: scroll-left 20s linear infinite; }
|
||||
.marquee[data-playing="false"] .marquee__track { animation-play-state: paused; }
|
||||
@media (prefers-reduced-motion: reduce) {
|
||||
.marquee__track { animation-play-state: paused; } /* paused by default */
|
||||
}
|
||||
@keyframes scroll-left { to { transform: translateX(-50%); } }
|
||||
```
|
||||
|
||||
```js
|
||||
const root = document.querySelector('.marquee');
|
||||
const btn = root.querySelector('.marquee__toggle');
|
||||
// Respect the OS setting for the initial state
|
||||
if (window.matchMedia('(prefers-reduced-motion: reduce)').matches) {
|
||||
root.dataset.playing = 'false';
|
||||
btn.textContent = 'Play';
|
||||
btn.setAttribute('aria-pressed', 'true');
|
||||
}
|
||||
btn.addEventListener('click', () => {
|
||||
const playing = root.dataset.playing === 'true';
|
||||
root.dataset.playing = String(!playing);
|
||||
btn.textContent = playing ? 'Play' : 'Pause';
|
||||
btn.setAttribute('aria-pressed', String(playing));
|
||||
});
|
||||
```
|
||||
|
||||
## Tier classification audit checklist
|
||||
|
||||
For each animation in the codebase, ask in order:
|
||||
|
||||
1. Is it essential to meaning (e.g. a progress bar, a diagram step)? -> Tier 3, keep.
|
||||
2. Does a large area move, scale, spin, or imply depth/self-motion (parallax, zoom hero, slide-over)? -> Tier 1, remove under reduce.
|
||||
3. Is it a small entrance with displacement (pop-in, slide-up)? -> Tier 2, replace displacement with a ≤200ms opacity fade.
|
||||
4. Is it only opacity/color/focus? -> Tier 3, keep (shorten if >300ms).
|
||||
5. Does it auto-play >5s (carousel, marquee, looping video bg)? -> Add a pause control (2.2.2) on top of any tier handling.
|
||||
|
||||
## Testing
|
||||
|
||||
- macOS: System Settings > Accessibility > Display > Reduce motion.
|
||||
- Windows 11: Settings > Accessibility > Visual effects > Animation effects (off).
|
||||
- Chrome DevTools: Rendering panel > "Emulate CSS media feature prefers-reduced-motion".
|
||||
- Verify the `change` listener: toggle the OS setting with the page open and confirm motion stops without reload.
|
||||
- Confirm `transitionend`/`animationend`-dependent flows still complete (the `0.01ms` rule).
|
||||
|
||||
---
|
||||
Honor prefers-reduced-motion at every tier and motion stays inclusive by default. Built by **[iart.ai](https://iart.ai/?utm_source=github&utm_medium=readme&utm_campaign=web-animation-skills&utm_content=skill_footer&utm_term=accessible-animation)** — the AI motion agent for editable, on-brand motion graphics.
|
||||
File renamed without changes.
@@ -0,0 +1,84 @@
|
||||
---
|
||||
name: after-effects
|
||||
description: This skill should be used when the user asks anything about Adobe After Effects — to "write an After Effects expression", "make a wiggle / loopOut / inertial bounce", "rig a control with a slider / null", "build a MOGRT / Essential Graphics template", "export AE to Lottie or Media Encoder"; OR to "export from After Effects", "export with transparency / an alpha channel", "fix a black background on export", "choose ProRes vs H.264", "which codec / what bitrate for 1080p / 4K", "stop H.264 disappearing from the Render Queue"; OR when "After Effects is slow / laggy / crashing / froze", "RAM preview won't play in real time", "AE is using all my memory / render takes forever", "how do I speed up After Effects"; OR to "organize my After Effects project", "relink missing footage", "fix broken links after moving files", "set a folder structure / naming conventions", "batch rename layers", or "write an ExtendScript / .jsx script". Covers expressions & rigging, export recipes, performance triage, and project hygiene.
|
||||
version: 0.1.0
|
||||
---
|
||||
|
||||
# After Effects
|
||||
|
||||
After Effects is GUI software, so this skill delivers knowledge and ready-to-paste assets — expressions, rig setups, export checklists, diagnostic flows, naming schemes, and ExtendScript — rather than a rendered file. It is a hub covering four domains; route to the matching reference for depth and complete recipes.
|
||||
|
||||
## Routing
|
||||
|
||||
| If the user wants to… | Go to |
|
||||
|---|---|
|
||||
| Write/debug an expression, rig sliders & nulls, build a MOGRT, export to Lottie | `references/expressions.md` (deep cookbook in `references/expression-library.md`) |
|
||||
| Choose a codec/container, export with alpha, fix a black background, set bitrate, recover H.264 | `references/export-recipes.md` |
|
||||
| Fix slow/laggy previews, slow renders, crashes, freezes, out-of-memory | `references/performance-triage.md` |
|
||||
| Organize the project, relink missing footage, set naming/folders, batch-automate with .jsx | `references/project-hygiene.md` |
|
||||
|
||||
The `.jsx` automation scripts live in `scripts/`.
|
||||
|
||||
## Expressions & rigging
|
||||
|
||||
Expressions are JavaScript evaluated on the property they are pasted on; `value` is that property's value, `time` is comp time in seconds, and `index`, `thisLayer`, `thisComp` are in scope. An expression overrides keyframes unless it incorporates `value`.
|
||||
|
||||
```js
|
||||
wiggle(2, 30); // 2 wiggles/sec, amplitude 30 (property units)
|
||||
loopOut("cycle"); // repeat keyframed range forever; "pingpong" / "offset" / "continue"
|
||||
seedRandom(index, true); // stable-but-unique per layer (timeless) before random()/wiggle()
|
||||
thisComp.layer("Lead").transform.position.valueAtTime(time - 0.2 * index); // staggered echo
|
||||
```
|
||||
|
||||
Inertial bounce (overshoot/settle after the last keyframe) and the full loop/wiggle/rigging set are in `references/expressions.md`.
|
||||
|
||||
Rig controllable motion: add a null with **Slider / Checkbox / Color / Angle / Point** control effects, then reference them and parent transforms to drive many layers from one.
|
||||
|
||||
```js
|
||||
ctrl = thisComp.layer("Controls");
|
||||
amt = ctrl.effect("Intensity")("Slider"); // Checkbox → 1/0, Color → [r,g,b,a]
|
||||
value * amt;
|
||||
```
|
||||
|
||||
Expose those controls via **Window → Essential Graphics** and **Export Motion Graphics Template** (.mogrt) for Premiere/AE editors.
|
||||
|
||||
## Export recipes
|
||||
|
||||
Two engines, and choosing wrong is the root of most export confusion:
|
||||
- **Render Queue (RQ)** — masters/intermediates: ProRes, image sequences, lossless, alpha.
|
||||
- **Adobe Media Encoder (AME)** — delivery: H.264 MP4, H.265, social presets.
|
||||
|
||||
Since AE CC 2014/2015 the native **H.264 output module was removed from the RQ** — make MP4s in AME, not the RQ. **H.264/MP4 cannot store alpha**, so a transparent comp exported to H.264 always fills with black; that is the classic "black background" complaint and not a bug. For transparency use **ProRes 4444**, a **PNG/TIFF sequence**, or **HEVC-alpha (Safari) + VP9/WebM-alpha (Chrome)**, with Output Module **Channels: RGB + Alpha**.
|
||||
|
||||
Quick targets: editor handoff → **ProRes 422 HQ**; master/grade or alpha → **ProRes 4444**; web/social/client → **H.264 via AME**, VBR 2-pass (~10–16 Mbps 1080p, ~35–45 Mbps 4K). Full matrix, social specs, and step-by-step alpha exports in `references/export-recipes.md`.
|
||||
|
||||
## Performance triage
|
||||
|
||||
Work top-down by symptom, cheapest fix first, and stop when it clears. Most settings are in `Edit > Preferences` (Win) / `After Effects > Settings` (Mac).
|
||||
|
||||
- **Slow previews:** Half/Third resolution → enable **Multi-Frame Rendering** → raise RAM allocation (leave ~6 GB for OS) → Adaptive fast previews → purge cache → Disk Cache on SSD/NVMe → solo heavy layers/effects → HW-accelerated decode → proxy heavy comps.
|
||||
- **Slow renders:** confirm MFR on → RQ for masters / AME for delivery → HW decode H.264 → pre-render slow precomps → cheaper effects → transcode long-GOP to ProRes.
|
||||
- **Crashes/freezes:** purge + empty disk cache → update **NVIDIA Studio** (not Game-Ready) drivers → reset prefs (`Ctrl/Cmd+Alt+Shift` on launch) → pull third-party plugins → free disk space → disable MFR if MFR-specific → roll back AE after a bad update.
|
||||
|
||||
MFR needs several GB RAM per active core. Ordered flows, exact preference paths, and the proxy workflow are in `references/performance-triage.md`.
|
||||
|
||||
## Project hygiene
|
||||
|
||||
Keep projects organized, portable, and automatable.
|
||||
|
||||
- **Folders:** numeric-prefixed bins (`01_Comps`, `02_Precomps`, `03_Footage`, …, `99_Old`) for stable sort order.
|
||||
- **Naming:** `PROJECT_section_descriptor_v01`; precomps `PRE_`; rename solids/nulls to their role (`CTRL_master`); no spaces/special chars for farm/cross-OS safety.
|
||||
- **Broken links:** AE references footage by path, so moving files breaks links. Double-click a missing item → **Replace Footage > File** and AE relinks the whole folder at once; enumerate with `File > Dependencies > Find Missing Footage`. **Always hand off projects via `File > Dependencies > Collect Files`**, never a bare `.aep`.
|
||||
- **ExtendScript (.jsx):** wrap batches in `app.beginUndoGroup(...) / app.endUndoGroup()`; apply effects by **matchName** (e.g. `"ADBE Gaussian Blur 2"`), not the display name. Ready scripts: `scripts/batch-rename.jsx`, `scripts/sequential-offset.jsx`, `scripts/apply-effect-to-layers.jsx`.
|
||||
|
||||
Full naming scheme, label-color system, relink/Collect-Files/Reduce workflows, and scripting setup in `references/project-hygiene.md`.
|
||||
|
||||
## Reference files
|
||||
|
||||
- `references/expressions.md` — expressions, rigging, MOGRT, Lottie/Media Encoder basics.
|
||||
- `references/expression-library.md` — deeper expression cookbook: tuned inertial bounce, all loop variants, advanced wiggle, valueAtTime echoes, seedRandom grids, full rigging + coordinate spaces, MOGRT and Lottie/Bodymovin steps, Media Encoder presets.
|
||||
- `references/export-recipes.md` — full codec/alpha/bitrate matrix, per-platform social specs, step-by-step transparency exports, AME preset cautions.
|
||||
- `references/performance-triage.md` — ordered preview/render/crash flows, preference paths and values, MFR/GPU/disk-cache tuning, pre-render & proxy workflow.
|
||||
- `references/project-hygiene.md` — folder template, naming and label systems, relink/Collect Files/Reduce details, scripting setup.
|
||||
- `scripts/batch-rename.jsx`, `scripts/sequential-offset.jsx`, `scripts/apply-effect-to-layers.jsx` — ExtendScript automations.
|
||||
</content>
|
||||
@@ -0,0 +1,168 @@
|
||||
# Export Recipes — Codec, Container, Alpha, Bitrate
|
||||
|
||||
Pick the correct codec, container, alpha handling, and bitrate for a given delivery target, and avoid the classic failures: black backgrounds where transparency was expected, H.264 that vanished from the Render Queue, and bloated or muddy files.
|
||||
|
||||
## The two export engines
|
||||
|
||||
After Effects has two output paths. Choosing the wrong one is the root of most export confusion.
|
||||
|
||||
- **Render Queue (RQ)** — `Composition > Add to Render Queue`. Best for mastering/intermediate formats: ProRes, image sequences, lossless, alpha. Renders inside AE.
|
||||
- **Adobe Media Encoder (AME)** — `Composition > Add to Adobe Media Encoder Queue` (or the RQ "Queue in AME" button). Best for delivery/compressed formats: H.264 MP4, H.265, social presets. Renders in a separate app so AE stays usable.
|
||||
|
||||
**Why H.264 disappeared from the Render Queue:** Since AE CC 2014/2015, Adobe removed the native H.264, H.264 Blu-ray, and MPEG-2 output modules from the RQ. To make an MP4, use AME — not the RQ. There is no setting to restore it in the RQ; that workflow is intentional.
|
||||
|
||||
## Decision tree
|
||||
|
||||
```
|
||||
Need transparency (alpha) in the final file?
|
||||
├─ YES, for an editor/compositor (NLE) → ProRes 4444 (.mov), RGB+Alpha, RQ
|
||||
│ └─ smaller, still alpha? → PNG sequence or TIFF sequence (RGB+Alpha)
|
||||
├─ YES, for the web/browser → dual export:
|
||||
│ • HEVC with alpha (.mov, Safari/iOS)
|
||||
│ • VP9/WebM with alpha (Chrome/Firefox/Edge)
|
||||
└─ NO alpha needed
|
||||
├─ Final delivery / upload (YouTube, social, client review) → H.264 MP4 via AME
|
||||
├─ Editorial / intermediate / grading → ProRes 422 HQ or 422 (.mov), RQ
|
||||
├─ Mastering / archival, highest fidelity → ProRes 4444 or lossless / image seq
|
||||
└─ Tiny looping clip, limited colors → GIF (via AME / Photoshop), or WebM
|
||||
```
|
||||
|
||||
## Transparency — the black background problem
|
||||
|
||||
H.264/MP4 **cannot store an alpha channel**. Exporting a comp with transparent areas to H.264 always fills them with black (or white). This is the single most common export complaint and it is not a bug.
|
||||
|
||||
To actually keep transparency:
|
||||
|
||||
1. Use a format that supports alpha: **ProRes 4444**, **PNG/TIFF sequence**, **HEVC-with-alpha**, or **VP9/WebM-with-alpha**.
|
||||
2. In the RQ Output Module, set **Channels: RGB + Alpha** and **Depth** to Millions of Colors+ (the "+" is the alpha).
|
||||
3. Choose a matte type: **Premultiplied (Matted with color)** for most cases; **Straight (Unmatted)** if the compositor explicitly wants straight alpha. Straight alpha avoids dark/light fringing on edges when re-composited, but only some apps import it cleanly.
|
||||
|
||||
For web transparent video, no single file plays everywhere. Ship two and use the HTML `<video>` element with multiple `<source>` tags: HEVC-alpha for Safari/iOS, VP9/WebM-alpha for Chromium/Firefox.
|
||||
|
||||
## Bitrate guidance (H.264 via AME)
|
||||
|
||||
Set in AME Export Settings → Video → Bitrate Settings.
|
||||
|
||||
- **Encoding:** VBR, 2 pass (better quality per byte than CBR or 1-pass).
|
||||
- **1080p30:** Target ~10–16 Mbps, Max ~20 Mbps.
|
||||
- **1080p60:** Target ~16–24 Mbps.
|
||||
- **4K30:** Target ~35–45 Mbps, Max ~55 Mbps.
|
||||
- **4K60:** Target ~50–68 Mbps.
|
||||
- Higher target/max for high-motion or grainy footage; lower for flat graphics/motion design.
|
||||
- For uploading to YouTube/Vimeo, lean to the high end — the platform re-encodes, so feed it a clean, high-bitrate master rather than over-compressing twice.
|
||||
|
||||
## Quick reference
|
||||
|
||||
| Target | Engine | Codec / Container | Channels | Bitrate / Notes |
|
||||
|---|---|---|---|---|
|
||||
| YouTube / Vimeo upload | AME | H.264 .mp4 | RGB | VBR 2-pass, 1080p ~16 Mbps / 4K ~45 Mbps |
|
||||
| Instagram / TikTok / Reels | AME | H.264 .mp4 | RGB | 1080×1920 or 1080×1080, ~10–14 Mbps |
|
||||
| Client review | AME | H.264 .mp4 | RGB | VBR 2-pass ~10–16 Mbps |
|
||||
| Editorial / hand to editor | RQ | ProRes 422 HQ .mov | RGB | Mezzanine; large but edit-friendly |
|
||||
| Mastering / grading | RQ | ProRes 4444 .mov | RGB(+A) | Highest fidelity, optional alpha |
|
||||
| Transparency → NLE | RQ | ProRes 4444 .mov | RGB+Alpha | Millions+; premultiplied usually |
|
||||
| Transparency → frames | RQ | PNG or TIFF sequence | RGB+Alpha | Lossless per-frame, robust |
|
||||
| Transparent web (Safari) | AME/RQ | HEVC w/ alpha .mov | RGB+Alpha | Pair with VP9 below |
|
||||
| Transparent web (Chrome) | AME/3rd-party | VP9 / WebM w/ alpha | RGB+Alpha | `yuva420p` alpha mode |
|
||||
| Looping clip, few colors | AME/PS | GIF or WebM | — | GIF = large/limited; prefer WebM |
|
||||
| Archival lossless | RQ | Lossless / PNG seq | RGB(+A) | Huge files |
|
||||
|
||||
## Gotchas
|
||||
|
||||
- **H.264 in the RQ is gone** — use AME. Don't search for a missing module.
|
||||
- **Black background = wrong codec.** Switching matte/straight settings won't help if the codec has no alpha. Change the codec first.
|
||||
- **"Millions of Colors" has no alpha; "Millions of Colors+" does.** The `+` is the alpha channel in RQ Depth.
|
||||
- **ProRes on Windows** is fully supported for export in modern AE; no extra codec install needed.
|
||||
- **GIF is rarely the right answer** — large files, dithered color, no real alpha softness. Prefer WebM/VP9 or short H.264 loops.
|
||||
- **Don't double-compress.** Master to ProRes/lossless, then make one H.264 from that — not H.264 from H.264.
|
||||
- **AME "Match Source"** presets can silently downscale or drop the bitrate; verify resolution and bitrate before queuing.
|
||||
- **Render multiple outputs efficiently:** in the RQ, one render item can have several Output Modules (e.g. ProRes master + PNG seq) from a single render pass.
|
||||
|
||||
---
|
||||
|
||||
# Codec & Export Matrix — Detailed Reference
|
||||
|
||||
## ProRes family — when to use which
|
||||
|
||||
| Variant | Use for | Alpha | Relative size |
|
||||
|---|---|---|---|
|
||||
| ProRes 422 Proxy | Offline edit, rough cuts | No | Smallest |
|
||||
| ProRes 422 LT | Lightweight editorial | No | Small |
|
||||
| ProRes 422 | General editorial | No | Medium |
|
||||
| ProRes 422 HQ | High-quality editorial / delivery to editor | No | Large |
|
||||
| ProRes 4444 | Mastering, grading, **transparency** | Yes | Larger |
|
||||
| ProRes 4444 XQ | Highest fidelity, HDR, max-quality alpha | Yes | Largest |
|
||||
|
||||
Rule of thumb: hand an editor **422 HQ**; master/keep alpha with **4444**.
|
||||
|
||||
## Full target → settings matrix
|
||||
|
||||
| Delivery target | Engine | Container | Codec | Resolution | Channels / Depth | Bitrate / Quality | Audio |
|
||||
|---|---|---|---|---|---|---|---|
|
||||
| YouTube 1080p | AME | .mp4 | H.264 | 1920×1080 | RGB, 8-bit | VBR 2-pass, Tgt 16 / Max 20 Mbps | AAC 320 kbps 48 kHz |
|
||||
| YouTube 4K | AME | .mp4 | H.264 | 3840×2160 | RGB, 8-bit | VBR 2-pass, Tgt 45 / Max 55 Mbps | AAC 384 kbps |
|
||||
| Vimeo 1080p | AME | .mp4 | H.264 | 1920×1080 | RGB | VBR 2-pass, Tgt 20 Mbps | AAC 320 kbps |
|
||||
| Instagram Feed | AME | .mp4 | H.264 | 1080×1080 or 1080×1350 | RGB | ~10–12 Mbps | AAC 128–256 kbps |
|
||||
| Instagram Reels / TikTok | AME | .mp4 | H.264 | 1080×1920 | RGB | ~12–14 Mbps | AAC 256 kbps |
|
||||
| X / Twitter | AME | .mp4 | H.264 | 1280×720 or 1080p | RGB | ~6–10 Mbps | AAC |
|
||||
| Broadcast delivery | RQ | .mov | ProRes 422 HQ | as spec (often 1080i/p) | RGB, 10-bit | — | PCM 48 kHz |
|
||||
| Editorial handoff | RQ | .mov | ProRes 422 HQ | comp size | RGB | — | PCM |
|
||||
| Color grading master | RQ | .mov | ProRes 4444 | comp size | RGB, 12-bit | — | PCM |
|
||||
| VFX plate / alpha to NLE | RQ | .mov | ProRes 4444 | comp size | RGB+Alpha, Millions+ | premultiplied | — |
|
||||
| Compositing frames | RQ | seq | PNG or 16-bit TIFF | comp size | RGB+Alpha | lossless | — |
|
||||
| EXR for VFX pipeline | RQ | seq | OpenEXR | comp size | RGB+Alpha, 32-bit float | linear/ACES | — |
|
||||
| Transparent web (Apple) | AME or RQ | .mov | HEVC w/ alpha | comp size | RGB+Alpha | quality ~ 60–80% | optional |
|
||||
| Transparent web (Chrome) | 3rd-party/ffmpeg | .webm | VP9 (yuva420p) | comp size | RGB+Alpha | CRF ~30 | optional |
|
||||
| Animated icon / loop | AME or PS | .gif / .webm | GIF / VP9 | small | indexed / RGBA | minimize frames | — |
|
||||
|
||||
## Transparency — step by step
|
||||
|
||||
### ProRes 4444 with alpha (Render Queue)
|
||||
1. `Composition > Add to Render Queue`.
|
||||
2. Click the blue **Output Module** text.
|
||||
3. Format: **QuickTime**. Click **Format Options** → Codec: **Apple ProRes 4444**.
|
||||
4. **Channels: RGB + Alpha**. **Depth: Millions of Colors+**.
|
||||
5. **Color: Premultiplied (Matted)** for most uses; choose **Straight (Unmatted)** only if the downstream app asks for straight alpha.
|
||||
6. Set Output To path, then **Render**.
|
||||
|
||||
### PNG / TIFF sequence with alpha (Render Queue)
|
||||
1. Add to RQ → Output Module.
|
||||
2. Format: **PNG Sequence** (or **TIFF Sequence**).
|
||||
3. **Channels: RGB + Alpha**, Depth **Millions of Colors+** (PNG) or 16-bit (TIFF).
|
||||
4. Output To a **dedicated empty folder** — sequences write one file per frame.
|
||||
|
||||
### HEVC with alpha (Apple/Safari)
|
||||
- In AME, choose **H.265 (HEVC)** and enable an alpha/transparency option where available, or use the QuickTime HEVC export with RGB+Alpha. Verify playback in Safari; Chrome will not show its alpha.
|
||||
|
||||
### VP9 / WebM with alpha (Chrome)
|
||||
- AME does not reliably produce alpha WebM. Render a ProRes 4444 or PNG sequence from AE, then encode with ffmpeg:
|
||||
- `ffmpeg -i master.mov -c:v libvpx-vp9 -pix_fmt yuva420p -b:v 0 -crf 30 out.webm`
|
||||
- `yuva420p` is the alpha-carrying pixel format; without it WebM has no transparency.
|
||||
|
||||
### HTML for cross-browser transparent video
|
||||
```html
|
||||
<video autoplay loop muted playsinline>
|
||||
<source src="clip.mov" type="video/quicktime"> <!-- HEVC alpha, Safari/iOS -->
|
||||
<source src="clip.webm" type="video/webm"> <!-- VP9 alpha, Chrome/Firefox -->
|
||||
</video>
|
||||
```
|
||||
|
||||
## Alpha matte types explained
|
||||
- **Straight (Unmatted):** color stored independent of alpha; cleanest edges when re-composited, but fewer apps import correctly.
|
||||
- **Premultiplied (Matted with color):** color blended with a matte color (usually black). Most compatible; can show fringing if the wrong matte color is assumed downstream.
|
||||
- When in doubt for NLE handoff, **premultiplied with black** is the safe default.
|
||||
|
||||
## AME preset cautions
|
||||
- **Match Source – High bitrate** can downscale to the source clip rather than the comp; confirm output resolution.
|
||||
- Always check **VBR 2-pass** is selected for final masters; presets sometimes default to 1-pass.
|
||||
- Use **Render at Maximum Depth** and **Use Maximum Render Quality** for scaling-heavy comps (slower but cleaner).
|
||||
- For social verticals, set the resolution explicitly — don't trust a 16:9 preset.
|
||||
|
||||
## Bitrate cheat sheet (H.264 VBR 2-pass)
|
||||
| Resolution / fps | Target Mbps | Max Mbps |
|
||||
|---|---|---|
|
||||
| 720p30 | 5–8 | 10 |
|
||||
| 1080p30 | 10–16 | 20 |
|
||||
| 1080p60 | 16–24 | 30 |
|
||||
| 4K30 | 35–45 | 55 |
|
||||
| 4K60 | 50–68 | 80 |
|
||||
@@ -0,0 +1,184 @@
|
||||
# After Effects Expression Library, Rigging & Export
|
||||
|
||||
A deeper cookbook. All expressions are JavaScript (the modern AE expression engine). They evaluate on the property they are pasted on, where `value`, `time`, `index`, `thisLayer`, `thisComp` are in scope.
|
||||
|
||||
## Inertial bounce (parameterized)
|
||||
|
||||
```js
|
||||
// Overshoot/settle after the most recent keyframe. Tune amp/freq/decay.
|
||||
amp = 0.10; // 0.05 = subtle, 0.2 = bouncy
|
||||
freq = 3.0; // oscillations per second
|
||||
decay = 5.0; // higher = settles faster
|
||||
|
||||
n = 0;
|
||||
if (numKeys > 0) {
|
||||
n = nearestKey(time).index;
|
||||
if (key(n).time > time) n--;
|
||||
}
|
||||
if (n === 0) {
|
||||
value;
|
||||
} else {
|
||||
t = time - key(n).time;
|
||||
v = velocityAtTime(key(n).time - thisComp.frameDuration / 10);
|
||||
value + v * amp * Math.sin(freq * t * 2 * Math.PI) / Math.exp(decay * t);
|
||||
}
|
||||
```
|
||||
|
||||
Inertial bounce works on multi-dimensional properties because `velocityAtTime` returns a vector; the arithmetic is per-component.
|
||||
|
||||
## Loop variants
|
||||
|
||||
```js
|
||||
loopOut("cycle"); // A B C A B C ...
|
||||
loopOut("pingpong"); // A B C B A B C ...
|
||||
loopOut("offset"); // continues accumulating the delta each cycle
|
||||
loopOut("continue"); // linear extension of the final velocity (no loop)
|
||||
loopOut("cycle", 3); // loop only the last 3 keyframes
|
||||
loopIn("cycle", 2); // loop the first 2 keyframes, backwards in time
|
||||
loopOutDuration("cycle", 2); // loop the last 2 SECONDS of keyframes
|
||||
```
|
||||
|
||||
Use `offset` for endless conveyor/scroll motion; `continue` for inertia past the last keyframe without oscillation.
|
||||
|
||||
## Wiggle — advanced
|
||||
|
||||
```js
|
||||
// Full signature: wiggle(freq, amp, octaves, amp_mult, time)
|
||||
wiggle(2, 30, 3, 0.5); // 3 octaves adds finer detail
|
||||
|
||||
// Per-axis wiggle (different amplitude X vs Y)
|
||||
x = wiggle(2, 50)[0];
|
||||
y = wiggle(2, 10)[1];
|
||||
[x, y];
|
||||
|
||||
// Wiggle only rotation while keeping keyframed position
|
||||
wiggle(1, 5); // on Rotation
|
||||
|
||||
// Smooth, looping ambient motion without true wiggle (loopable):
|
||||
amp = 20; period = 4; // seconds
|
||||
[Math.sin(time / period * 2 * Math.PI) * amp,
|
||||
Math.cos(time / period * 2 * Math.PI) * amp] + value;
|
||||
```
|
||||
|
||||
`wiggle` is non-looping noise; for seamless loops use periodic sin/cos as above.
|
||||
|
||||
## Stable randomness across a grid
|
||||
|
||||
```js
|
||||
seedRandom(index, true); // timeless=true → constant over time, varies per layer
|
||||
startDelay = random(0, 0.5); // each layer gets a stable random delay
|
||||
opacity = ease(time, startDelay, startDelay + 0.4, 0, 100);
|
||||
```
|
||||
|
||||
`seedRandom(index, false)` (timeless=false) lets `random()` vary over time — use for flicker; `true` for stable offsets.
|
||||
|
||||
## Time remap & valueAtTime echoes
|
||||
|
||||
```js
|
||||
// Trailing/echo: sample the lead layer in the past, staggered by index
|
||||
delay = 0.08 * (index - 1);
|
||||
thisComp.layer("Lead").transform.position.valueAtTime(time - delay);
|
||||
|
||||
// Speed-ramp a time-remapped layer using easing on the source time
|
||||
src = thisComp.layer("Source");
|
||||
linear(time, 0, 2, 0, src.source.duration); // play a 2s window of the source
|
||||
|
||||
// Sample own value in the past for motion smear / trail
|
||||
valueAtTime(time - 0.1);
|
||||
```
|
||||
|
||||
## Rigging walkthrough
|
||||
|
||||
### Control types and how to read them
|
||||
|
||||
```js
|
||||
ctrl = thisComp.layer("Controls");
|
||||
ctrl.effect("Intensity")("Slider"); // number
|
||||
ctrl.effect("Visible")("Checkbox"); // 1 or 0
|
||||
ctrl.effect("Brand")("Color"); // [r,g,b,a] 0..1
|
||||
ctrl.effect("Spin")("Angle"); // degrees
|
||||
ctrl.effect("Anchor")("Point"); // [x,y]
|
||||
```
|
||||
|
||||
### One slider, staggered reveal across N layers
|
||||
|
||||
```js
|
||||
// On each layer's Opacity:
|
||||
master = thisComp.layer("Controls").effect("Reveal")("Slider"); // 0..100 driver
|
||||
per = 6; // frames of stagger per layer
|
||||
shift = framesToTime(per * (index - 1));
|
||||
ease(master, 0, 100, 0, 100) * (time > shift ? 1 : 0);
|
||||
```
|
||||
|
||||
### Coordinate-space conversions
|
||||
|
||||
```js
|
||||
// Place this layer where another parented layer appears in comp space
|
||||
target = thisComp.layer("Marker");
|
||||
fromComp(target.toComp(target.anchorPoint));
|
||||
|
||||
// World position of a point on this layer
|
||||
toComp([0, 0]);
|
||||
```
|
||||
|
||||
`toComp` converts layer space → composition space; `fromComp` does the inverse. Use them whenever layers are parented or live in different (nested) comps.
|
||||
|
||||
### Linking many layers to a master null
|
||||
|
||||
1. Select all children → set Parent to the null.
|
||||
2. Animate only the null; children inherit transform.
|
||||
3. For non-transform links (effects, opacity), pick-whip to the control layer's effect.
|
||||
|
||||
## Essential Graphics / MOGRT export steps
|
||||
|
||||
1. **Window → Essential Graphics**, choose the master comp.
|
||||
2. Drag exposed properties (Slider, Checkbox, Color, Text Source, Media replacement) into the panel.
|
||||
3. Add **Group** headers, rename controls, fill comment fields for editors.
|
||||
4. Use **Drop-Zone / Media Replacement** for swappable footage/logos.
|
||||
5. Click **Export Motion Graphics Template**, choose destination (Local Templates Folder / Library / file). Toggle "Make fonts available" and check "Raster/vector" compatibility for Premiere.
|
||||
6. Test in Premiere Pro's Essential Graphics → Browse panel.
|
||||
|
||||
Keep all motion driven by expressions referencing the exposed controls so editors only touch the exposed params; hide internal layers with shy.
|
||||
|
||||
## Lottie / Bodymovin export
|
||||
|
||||
Supported reliably:
|
||||
- Shape layers, solids, transforms (position/scale/rotation/opacity/anchor).
|
||||
- Masks and track mattes (alpha), parenting, basic gradients.
|
||||
- Trim Paths, simple repeaters.
|
||||
- Expressions: enable in Bodymovin settings, but verify on the target renderer — `lottie-web`, lottie-ios, and lottie-android differ in expression and effect support.
|
||||
|
||||
Not supported / risky (bake or avoid):
|
||||
- Blend modes, most native Effects, layer blurs, 3D layers/cameras, time remapping, adjustment-layer effects.
|
||||
|
||||
Workflow:
|
||||
1. Install Bodymovin extension; **Window → Extensions → Bodymovin**.
|
||||
2. Select comp(s), set destination, choose Standard/Demo.
|
||||
3. Settings: enable "Glyphs"/"Hidden", "Expressions" only if needed; "Assets" → export images or use base64.
|
||||
4. Render `data.json`. Preview in a Lottie player; check file size and that masks/mattes survived.
|
||||
5. For web, load with `lottie-web`:
|
||||
|
||||
```js
|
||||
import lottie from 'lottie-web';
|
||||
lottie.loadAnimation({
|
||||
container: document.getElementById('lottie'),
|
||||
renderer: 'svg', // 'canvas' for heavy fills, better perf
|
||||
loop: true, autoplay: true,
|
||||
path: '/data.json',
|
||||
});
|
||||
```
|
||||
|
||||
## Media Encoder presets
|
||||
|
||||
| Use | Codec / format | Settings |
|
||||
|---|---|---|
|
||||
| Web/social delivery | H.264 (MP4) | VBR 2-pass, 1080p ~12–16 Mbps; 4K ~35–50 Mbps |
|
||||
| Master/intermediate | ProRes 422 HQ (MOV) | full range, matched fps |
|
||||
| With alpha | ProRes 4444 (MOV) | enable alpha channel |
|
||||
| Lossless interchange | PNG sequence or ProRes 4444 | per-frame, alpha |
|
||||
| GIF | via Media Encoder/Photoshop | reduce palette, dither, cap dimensions |
|
||||
|
||||
Tips:
|
||||
- Match the comp frame rate; avoid frame-blending unless intentionally retiming.
|
||||
- H.264 cannot store alpha — composite onto a background or use ProRes 4444 / PNG.
|
||||
- For crisp text, render at the delivery resolution (don't upscale); set quality to maximum and use 2-pass VBR.
|
||||
@@ -0,0 +1,134 @@
|
||||
# Expressions, Rigging & MOGRT
|
||||
|
||||
After Effects is GUI software, so this delivers knowledge: ready-to-paste JavaScript expressions, rigging setups that make motion controllable, and template/export pipelines. Expressions read on the property they are pasted on; `value` is that property's keyframed/static value, `time` is the composition time in seconds, and `index`, `thisLayer`, `thisComp` are in scope.
|
||||
|
||||
For a deeper cookbook (tuned inertial bounce, every loop variant, advanced per-axis wiggle, `valueAtTime` echoes, `seedRandom` grids, full rigging walkthrough, Essential Graphics → MOGRT steps, Lottie/Bodymovin + Media Encoder presets), see `expression-library.md`.
|
||||
|
||||
## Core expressions
|
||||
|
||||
### Inertial bounce (overshoot after the last keyframe)
|
||||
|
||||
Paste on a Position, Scale, or Rotation property. It continues the velocity at the final keyframe into a damped sine — the classic "settle" motion.
|
||||
|
||||
```js
|
||||
amp = 0.08; // overshoot amount
|
||||
freq = 2.5; // oscillations per second
|
||||
decay = 6.0; // how fast it settles
|
||||
n = 0;
|
||||
if (numKeys > 0) {
|
||||
n = nearestKey(time).index;
|
||||
if (key(n).time > time) n--;
|
||||
}
|
||||
if (n > 0) {
|
||||
t = time - key(n).time;
|
||||
v = velocityAtTime(key(n).time - 0.001);
|
||||
value + v * (amp * Math.sin(freq * t * 2 * Math.PI) / Math.exp(decay * t));
|
||||
} else {
|
||||
value;
|
||||
}
|
||||
```
|
||||
|
||||
### Looping
|
||||
|
||||
```js
|
||||
loopOut("cycle"); // repeat keyframed range forever
|
||||
loopOut("pingpong"); // bounce back and forth
|
||||
loopOut("offset"); // continue, accumulating (e.g. continuous travel)
|
||||
loopOut("continue"); // extend final velocity linearly
|
||||
loopOut("cycle", 2); // loop only the last 2 keyframes
|
||||
loopIn("cycle"); // mirror, before the first keyframe
|
||||
```
|
||||
|
||||
### Wiggle and stable randomness
|
||||
|
||||
```js
|
||||
wiggle(2, 30); // 2 wiggles/sec, amplitude 30 (units match the property)
|
||||
seedRandom(index, true); // unique-but-stable per layer; timeless=true
|
||||
random(0, 100); // stable after seedRandom
|
||||
wiggle(freq, amp, octaves=1, amp_mult=0.5, t=time); // full signature
|
||||
```
|
||||
|
||||
`seedRandom(index, true)` before `random()` or `wiggle()` makes each layer differ but stay constant across renders — essential for grids of layers that must not flicker.
|
||||
|
||||
### Time remap & value-at-time
|
||||
|
||||
```js
|
||||
// Sample another property/layer at a shifted time (echo/trailing motion)
|
||||
delay = 0.2 * index;
|
||||
thisComp.layer("Lead").transform.position.valueAtTime(time - delay);
|
||||
|
||||
// Speed up a precomp via time remap
|
||||
linear(time, 0, thisComp.duration, 0, 6); // 6s source mapped over comp duration
|
||||
```
|
||||
|
||||
## Rigging
|
||||
|
||||
Make motion controllable instead of hand-keyed:
|
||||
|
||||
1. Add a null/control layer (often a "Controls" layer). Add **Slider Control**, **Checkbox Control**, **Color Control**, **Angle Control**, or **Point Control** effects to it.
|
||||
2. Reference them with the pick-whip or by path:
|
||||
|
||||
```js
|
||||
ctrl = thisComp.layer("Controls");
|
||||
amt = ctrl.effect("Intensity")("Slider"); // Slider Control → ADBE Slider Control-0001
|
||||
on = ctrl.effect("Enable")("Checkbox"); // Checkbox: 1 or 0
|
||||
col = ctrl.effect("Tint")("Color");
|
||||
|
||||
if (on == 1) value * amt else value;
|
||||
```
|
||||
|
||||
3. Parent transforms to a null so one move drives many layers. Use `toComp`/`fromComp` to convert coordinate spaces when layers are parented or in different comps.
|
||||
|
||||
```js
|
||||
// Stagger N layers off one master slider
|
||||
master = thisComp.layer("Controls").effect("Reveal")("Slider");
|
||||
delay = 4 * index; // 4 frames per layer
|
||||
master.valueAtTime(time - framesToTime(delay));
|
||||
```
|
||||
|
||||
## Essential Graphics / MOGRT
|
||||
|
||||
1. Open **Window → Essential Graphics**, pick the comp as the Master.
|
||||
2. Drag the Slider/Checkbox/Color/Text source properties into the panel to expose them.
|
||||
3. Group, rename, and set comment fields for editors.
|
||||
4. **Export Motion Graphics Template** → a `.mogrt` usable in Premiere Pro / AE. Keep driving expressions referencing the exposed controls so editors change only the exposed params.
|
||||
|
||||
Set "Allow fonts to substitute" off and embed/package fonts where possible so the template renders consistently elsewhere.
|
||||
|
||||
## Export from expressions/template work
|
||||
|
||||
### To Lottie (Bodymovin / `@lottiefiles/bodymovin`)
|
||||
|
||||
- Stick to Lottie-supported features: shape layers, transforms, masks, track mattes, basic expressions converted to keyframes.
|
||||
- Avoid blur-heavy effects, blend modes, 3D layers, and most native effects — they don't translate.
|
||||
- Bake expressions to keyframes if the renderer is strict, or use the `expressions` flag in Bodymovin and test on the target player (web/iOS/Android renderers differ).
|
||||
- Run **Bodymovin → Render** to produce `data.json` (+ optional images). Verify in a Lottie preview before handoff.
|
||||
|
||||
### To video (Media Encoder)
|
||||
|
||||
- **File → Export → Add to Adobe Media Encoder Queue** (or render queue for AE-native).
|
||||
- Delivery: **H.264** (MP4), bitrate ~10–20 Mbps for 1080p, VBR 2-pass.
|
||||
- Master/intermediate: **ProRes 422 HQ** (or ProRes 4444 when alpha is needed).
|
||||
- Transparency: ProRes 4444 or PNG/QuickTime with an alpha channel; H.264 cannot carry alpha. (See `export-recipes.md` for the full codec/alpha/bitrate matrix.)
|
||||
|
||||
## Quick reference
|
||||
|
||||
| Goal | Expression |
|
||||
|---|---|
|
||||
| Loop keyframes | `loopOut("cycle")` |
|
||||
| Continuous travel | `loopOut("offset")` |
|
||||
| Subtle life | `wiggle(2, 20)` |
|
||||
| Stable per-layer random | `seedRandom(index,true); random(...)` |
|
||||
| Settle/overshoot | inertial bounce (above) |
|
||||
| Echo another layer | `valueAtTime(time - delay)` |
|
||||
| Read a slider | `effect("Name")("Slider")` |
|
||||
| Frames ↔ seconds | `framesToTime(n)` / `timeToFrames(t)` |
|
||||
|
||||
## Gotchas
|
||||
|
||||
- An expression overrides keyframes on that property unless it incorporates `value`; start most expressions from `value`.
|
||||
- `index` is the layer's stacking number — it changes if layers are reordered; prefer named lookups for stable rigs.
|
||||
- Expression errors disable the expression and show a yellow banner; check the property's path names (effect names must match exactly, including duplicates' suffixes).
|
||||
- Pre-compose for reuse; name layers; use shy/lock and guide layers for safe areas before handoff.
|
||||
</content>
|
||||
</invoke>
|
||||
@@ -0,0 +1,138 @@
|
||||
# Performance Triage — Slow, Laggy, Crashing, Frozen
|
||||
|
||||
Diagnose slow previews, slow renders, freezes, and crashes in a fixed order, from cheapest fix to most invasive. Work top-down and stop when the symptom clears — most issues are solved in the first few steps.
|
||||
|
||||
Most fixes live in Preferences. Open `Edit > Preferences` (Windows) or `After Effects > Settings/Preferences` (macOS).
|
||||
|
||||
## First: identify the symptom
|
||||
|
||||
- **Slow / non-real-time previews (RAM preview)** → Flow A
|
||||
- **Slow renders (final output)** → Flow B
|
||||
- **Crashes / freezes / hangs** → Flow C
|
||||
|
||||
## Flow A — Slow previews (do in order)
|
||||
|
||||
1. **Set Resolution to Auto/Half/Third.** In the Composition viewer, change Resolution from Full to **Half** or **Third**. Adaptive/Draft resolution gives the biggest instant win.
|
||||
2. **Enable Multi-Frame Rendering (MFR).** `Preferences > Memory & Performance > Enable Multi-Frame Rendering`. Uses all CPU cores for preview and render (AE 2022+). Confirm "CPUs reserved for other applications" isn't set too high.
|
||||
3. **Check RAM allocation.** `Preferences > Memory & Performance`. Leave ~6 GB for the OS; give the rest to AE. Too little RAM = a tiny green preview bar.
|
||||
4. **Set Fast Previews to Adaptive Resolution.** Viewer's lightning-bolt icon → **Adaptive Resolution** (degrades resolution only while interacting).
|
||||
5. **Purge the cache.** `Edit > Purge > All Memory & Disk Cache`. Stale/full cache stalls previews.
|
||||
6. **Verify the Disk Cache is on a fast drive.** `Preferences > Media & Disk Cache` → Enable Disk Cache, point it at a fast **SSD/NVMe**, give it 50–100+ GB. Never on a slow external HDD.
|
||||
7. **Solo the offending layer/effect.** Toggle effects off (the fx switch) or solo layers to find the bottleneck. Heavy culprits: blurs, glows, Mocha/tracking, particles, expressions, large 3D, and many third-party plugins.
|
||||
8. **Enable GPU / hardware-accelerated decoding.** `Preferences > Video Preview` (Mercury GPU) and `Preferences > Import > Hardware Accelerate H.264/HEVC decoding`. Helps long-GOP source footage.
|
||||
9. **Pre-render or proxy heavy comps.** Pre-render a finished/slow precomp to ProRes and set it as a **proxy** (`File > Create Proxy`, or right-click footage → Set Proxy). Frees compute for the part being worked on.
|
||||
10. **Trim the work area** to just the section in progress so RAM preview fills faster.
|
||||
|
||||
## Flow B — Slow renders (do in order)
|
||||
|
||||
1. **Confirm Multi-Frame Rendering is on** (`Memory & Performance`) — the single largest render speedup on multi-core CPUs.
|
||||
2. **Render with the Render Queue for masters, AME for delivery** — and don't run heavy work in AE while AME renders.
|
||||
3. **Enable hardware-accelerated decoding** for H.264/HEVC sources (`Preferences > Import`).
|
||||
4. **Pre-render slow precomps** once and reuse them, instead of recomputing every frame. Heavy effect stacks, time-remapping, and 3rd-party renderers benefit most.
|
||||
5. **Replace effects with cheaper equivalents** where possible (e.g., Fast Box Blur over Gaussian; native over plugin).
|
||||
6. **Convert long-GOP source to an intermediate** (ProRes/DNxHR). Decoding H.264 every frame is slow; ProRes is cheap to read.
|
||||
7. **Check the renderer:** `Composition > Composition Settings > 3D Renderer`. Classic 3D is fastest; Cinema 4D/Ray-traced renderers are far slower.
|
||||
8. **Disk Cache on NVMe** so repeated frames aren't recomputed.
|
||||
9. **Close other apps**, especially other Adobe apps and browsers, to free RAM/CPU for MFR.
|
||||
|
||||
## Flow C — Crashes / freezes / hangs (do in order)
|
||||
|
||||
1. **Purge cache** (`Edit > Purge > All`). A full/corrupt cache causes hangs.
|
||||
2. **Clear the Disk Cache folder** in `Preferences > Media & Disk Cache > Empty Disk Cache`. Corrupt cache files cause crash-on-open.
|
||||
3. **Update GPU drivers** (NVIDIA Studio driver / AMD). Outdated/Game-Ready drivers cause Mercury GPU crashes. As a test, switch Project renderer GPU→CPU (`File > Project Settings > Video Rendering and Effects: Mercury Software Only`).
|
||||
4. **Reset Preferences:** hold `Ctrl+Alt+Shift` (Win) / `Cmd+Opt+Shift` (Mac) while launching AE. Corrupt prefs are a top crash cause.
|
||||
5. **Disable third-party plugins** by temporarily moving them out of the plug-ins folder, then reintroduce to find the offender. Old plugins are a leading crash/freeze source after AE updates.
|
||||
6. **Check Disk Cache and Output drives for free space.** A full scratch/cache disk causes freezes mid-render.
|
||||
7. **Lower or disable MFR** if crashes appear only during multi-frame render — some plugins are not MFR-safe; reserve more CPUs or disable MFR for those projects.
|
||||
8. **Roll back the AE version** if crashes started right after an update. Install a previous version via Creative Cloud (Other Versions) — many crash waves are version-specific regressions.
|
||||
9. **Look for a single corrupt asset** — import comps one at a time, or replace footage, to isolate a bad file.
|
||||
|
||||
## Quick reference
|
||||
|
||||
| Symptom | First three moves |
|
||||
|---|---|
|
||||
| Choppy RAM preview | Half resolution → enable MFR → purge cache |
|
||||
| Tiny green preview bar | Raise RAM allocation → SSD disk cache → trim work area |
|
||||
| Slow final render | Enable MFR → HW decode H.264 → pre-render precomps |
|
||||
| Crash on launch | Reset prefs (modifier keys) → empty disk cache → update GPU driver |
|
||||
| Crash mid-render | Free disk space → disable/reserve CPUs for MFR → disable 3rd-party plugins |
|
||||
| Started after update | Roll back AE version → update plugins → reset prefs |
|
||||
| Laggy with footage | HW-accelerated decode → transcode to ProRes → proxy heavy comps |
|
||||
|
||||
## Gotchas
|
||||
|
||||
- **MFR needs RAM per core.** With many cores but little RAM, MFR can underperform or stall — aim for several GB per active core.
|
||||
- **Game-Ready drivers crash AE.** Prefer the **Studio** driver branch on NVIDIA.
|
||||
- **Disk Cache on an external HDD is worse than none** — it must be SSD/NVMe to help.
|
||||
- **Plugins lag behind AE updates.** After a major AE upgrade, a sudden crash wave usually means a plugin needs updating or is not MFR-safe.
|
||||
- **Purging clears the green bar.** Previews must rebuild afterward; that initial slowness is expected, not a new problem.
|
||||
- **CPU/GPU effects are not equal.** A few GPU-accelerated effects are fast; mixing many CPU-only effects forces round-trips that kill preview speed.
|
||||
- **Don't render in AE and AME simultaneously** on the same machine — they fight for cores and RAM.
|
||||
|
||||
---
|
||||
|
||||
# AE Performance — Detailed Diagnostics Reference
|
||||
|
||||
## Preference locations and recommended values
|
||||
|
||||
| Setting | Path | Recommended |
|
||||
|---|---|---|
|
||||
| RAM for AE | Preferences > Memory & Performance | Total RAM minus ~6 GB for OS |
|
||||
| Multi-Frame Rendering | Memory & Performance > Enable MFR | On; reserve 0–2 CPUs for other apps |
|
||||
| Disk Cache | Media & Disk Cache > Enable Disk Cache | On, SSD/NVMe, 50–150 GB |
|
||||
| Conformed media cache | Media & Disk Cache | On SSD, separate from project if possible |
|
||||
| HW decode (H.264/HEVC) | Import > Hardware Accelerate Decoding | On |
|
||||
| Mercury GPU | Project Settings > Video Rendering and Effects | GPU (CPU as crash test) |
|
||||
| Fast Previews | Viewer lightning icon | Adaptive Resolution |
|
||||
|
||||
## Multi-Frame Rendering (MFR) tuning
|
||||
- Introduced in AE 2022 (22.x); renders multiple frames in parallel across CPU cores for both preview and final render.
|
||||
- **RAM is the limiter.** Each rendering frame needs memory; with too little RAM, AE quietly reduces the cores it uses. Target several GB of free RAM per logical core you want active.
|
||||
- "CPUs reserved for other applications" trades render speed for system responsiveness. Set 0–2 on a dedicated machine.
|
||||
- Some legacy/3rd-party effects are **not MFR-safe** and can crash or render incorrectly under MFR. If a specific project crashes only with MFR on, disable MFR for that project or update the plugin.
|
||||
|
||||
## GPU and drivers
|
||||
- Use the **NVIDIA Studio Driver** (not Game Ready) for stability with Adobe apps; keep AMD drivers current too.
|
||||
- Mercury GPU acceleration speeds some effects and the renderer. If AE crashes on launch or while playing back, switch `Project Settings > Video Rendering and Effects` to **Mercury Software Only** to confirm GPU/driver fault, then update drivers.
|
||||
- Hardware-accelerated **decoding** (separate from rendering) speeds reading H.264/HEVC source footage; enable in `Preferences > Import`.
|
||||
|
||||
## Disk cache sizing and placement
|
||||
- Put the disk cache on the **fastest local drive** (internal NVMe ideal). Never on a slow USB HDD or a network drive.
|
||||
- 50–150 GB is typical; more helps long projects retain cached frames between sessions.
|
||||
- Symptoms of a bad cache: hangs on open, garbage frames, refusal to play. Fix via `Empty Disk Cache` and `Edit > Purge > All`.
|
||||
- Keep the cache drive from filling up — a full cache/scratch disk causes mid-render freezes.
|
||||
|
||||
## Pre-render and proxy workflow
|
||||
1. Identify a slow, finished precomp (heavy effects, particles, 3D, tracking).
|
||||
2. Add it to the Render Queue and render to **ProRes 422/422 HQ** (or PNG sequence).
|
||||
3. Right-click the footage/comp in the Project panel → **Set Proxy > File**, select the rendered file. A box icon shows the proxy is active.
|
||||
4. Toggle the proxy off for final render if you want to re-render at full quality, or keep it if the pre-render is final.
|
||||
5. Alternatively `File > Create Proxy > Movie/Still` to queue a proxy directly.
|
||||
- Proxies let AE substitute a cheap-to-read file for an expensive comp/footage during editing.
|
||||
|
||||
## Heavy effect culprits (preview/render cost)
|
||||
- Gaussian Blur, Camera Lens Blur, Glow → use Fast Box Blur where acceptable.
|
||||
- Particle systems (Particular, Form), Element 3D, Plexus.
|
||||
- Mocha tracking, Warp Stabilizer (analysis), motion tracking.
|
||||
- Expressions that read many layers/time, especially per-frame heavy ones.
|
||||
- Nested precomps with collapsed transformations and continuous rasterization.
|
||||
- Ray-traced / Cinema 4D 3D renderer vs Classic 3D.
|
||||
|
||||
## Version-specific culprits
|
||||
- After a **major AE update**, a sudden crash/slowdown wave usually traces to a third-party plugin not yet updated for that AE version — update plugins or remove them to test.
|
||||
- If problems began immediately after updating AE, install the **previous version** from Creative Cloud → app → Other Versions, and report the regression.
|
||||
- Reset corrupt preferences by holding `Ctrl+Alt+Shift` (Win) / `Cmd+Opt+Shift` (Mac) during launch; this resolves many post-update oddities.
|
||||
|
||||
## Isolation checklist for crashes
|
||||
1. Reset preferences (modifier-key launch).
|
||||
2. Empty disk cache + Purge All.
|
||||
3. Update GPU driver (Studio branch).
|
||||
4. Move 3rd-party plugins out, relaunch, reintroduce one at a time.
|
||||
5. Switch Mercury to Software Only to rule out GPU.
|
||||
6. Import comps/footage incrementally to find a corrupt asset.
|
||||
7. Disable MFR for the project if crashes are MFR-specific.
|
||||
8. Roll back AE version if the crash wave is version-correlated.
|
||||
|
||||
## When to pre-compose vs pre-render
|
||||
- **Pre-compose** to organize and to apply an effect to a group — does not by itself speed anything up (it can even add overhead).
|
||||
- **Pre-render** (render to a file + use as proxy/footage) when a precomp is finished and slow — this is the actual performance win.
|
||||
@@ -0,0 +1,188 @@
|
||||
# Project Hygiene — Organize, Relink, ExtendScript
|
||||
|
||||
Keep AE projects organized, portable, and automatable: consistent naming, a clear folder/bin structure, label discipline, pre-comp discipline, reliable relinking when files move, and ExtendScript (.jsx) automation for repetitive tasks.
|
||||
|
||||
## Folder (bin) structure
|
||||
|
||||
Create folders in the Project panel (the folder icon at the bottom). A reliable layout:
|
||||
|
||||
```
|
||||
01_Comps/ finished/active compositions
|
||||
02_Precomps/ nested precomps
|
||||
03_Footage/ imported video
|
||||
04_Images/ stills, logos, textures
|
||||
05_Audio/
|
||||
06_Solids/ (AE's auto "Solids" folder — keep it here)
|
||||
07_Assets_3D/
|
||||
99_Old/ deprecated comps/layers, not deleted yet
|
||||
```
|
||||
|
||||
Numeric prefixes force a stable sort order. After importing, immediately drag items into the right bin — `File > Reduce Project` and `File > Consolidate All Footage` help later, but discipline up front prevents chaos.
|
||||
|
||||
## Naming conventions
|
||||
|
||||
- **Comps:** `PROJECT_section_descriptor_v01` (e.g., `BRAND_intro_logoBuild_v03`). Version with zero-padded `v01`, `v02`.
|
||||
- **Precomps:** prefix `PRE_` or suffix `_pre` so they're obvious in lists.
|
||||
- **Layers:** rename solids/nulls to their role (`CTRL_master`, `BG_gradient`, `MATTE_text`). Never ship "Black Solid 12".
|
||||
- **No spaces / special chars** in filenames destined for render farms or cross-OS sharing — use `_` and `-`.
|
||||
- Keep names short but unique; long names truncate in the timeline.
|
||||
|
||||
## Label colors
|
||||
|
||||
Use the Label color (the swatch left of each Project/Timeline item) as a visual system. Pick a convention and apply it consistently, e.g.:
|
||||
- Red = control/null layers
|
||||
- Blue = footage
|
||||
- Green = precomps
|
||||
- Yellow = text
|
||||
- Purple = adjustment/effects layers
|
||||
|
||||
Right-click an item → **Label** to set. Select multiple, then `Edit > Label > Select Label Group` to act on a whole color at once. Customize label names/colors in `Preferences > Labels`.
|
||||
|
||||
## Pre-comp discipline
|
||||
|
||||
- Pre-compose (`Layer > Pre-compose`, `Ctrl/Cmd+Shift+C`) to **group** related layers and to apply one effect to a group — not reflexively for everything.
|
||||
- When pre-composing a single layer, choose **"Leave all attributes in"** vs **"Move all attributes into the new composition"** deliberately: "Move" carries transforms/effects inside; "Leave" keeps them on the outer layer.
|
||||
- Name the precomp immediately and file it in `02_Precomps`.
|
||||
- Avoid deep nesting beyond a few levels — it slows navigation and makes relinking/debugging painful.
|
||||
- Match precomp duration and frame rate to need; an over-long precomp wastes cache.
|
||||
|
||||
## The "moved one file and everything broke" rescue
|
||||
|
||||
AE references footage by file path. Moving, renaming, or sending a project without its assets breaks links (shown as **colored bars / "Missing Footage"** placeholders).
|
||||
|
||||
### Fix options, in order
|
||||
1. **Relink one, fix many:** double-click a missing item (or right-click → **Replace Footage > File**). Point it at the moved file; AE offers to relink *all* missing items from the same folder automatically. This single step usually fixes the whole project.
|
||||
2. **Find Missing Footage:** `File > Dependencies > Find Missing Footage` lists every broken link to resolve.
|
||||
3. **Replace Footage:** right-click footage → **Replace Footage > File** to swap an asset while keeping every use, effect, and keyframe intact.
|
||||
|
||||
### Prevent it: Collect Files
|
||||
Before moving or sharing a project, use `File > Dependencies > Collect Files`. This copies the project plus every used asset into one new folder with relative structure, so links survive on any machine. Always hand off projects as a Collect Files package, not a bare `.aep`.
|
||||
|
||||
Related: `File > Dependencies > Consolidate All Footage` (merge duplicate imports), `Remove Unused Footage`, and `Reduce Project` (strip everything not used by selected comps) to slim a project before collecting.
|
||||
|
||||
## Batch automation with ExtendScript (.jsx)
|
||||
|
||||
AE scripts (ExtendScript / JSX) automate repetitive work. Run via `File > Scripts > Run Script File...`, or place in the **ScriptUI Panels** folder to dock as a panel. Always wrap edits in `app.beginUndoGroup("name") ... app.endUndoGroup()` so one Undo reverts the whole batch.
|
||||
|
||||
Common automations (full code in `../scripts/`):
|
||||
- **Batch rename** selected layers with a base name + auto-increment (`../scripts/batch-rename.jsx`).
|
||||
- **Sequential offset** — stagger selected layers in time by N frames each, a staggered "domino" start (`../scripts/sequential-offset.jsx`).
|
||||
- **Apply an effect** (e.g., a Gaussian Blur, or any matchName) across all selected layers at once (`../scripts/apply-effect-to-layers.jsx`).
|
||||
|
||||
Minimal pattern:
|
||||
```javascript
|
||||
app.beginUndoGroup("My Batch Op");
|
||||
var comp = app.project.activeItem;
|
||||
if (comp && comp instanceof CompItem) {
|
||||
var sel = comp.selectedLayers;
|
||||
for (var i = 0; i < sel.length; i++) {
|
||||
// operate on sel[i]
|
||||
}
|
||||
}
|
||||
app.endUndoGroup();
|
||||
```
|
||||
|
||||
## Quick reference
|
||||
|
||||
| Task | How |
|
||||
|---|---|
|
||||
| New bin | Folder icon at bottom of Project panel |
|
||||
| Set label color | Right-click item → Label |
|
||||
| Relink missing footage | Double-click item / Replace Footage > File |
|
||||
| List broken links | File > Dependencies > Find Missing Footage |
|
||||
| Package for handoff | File > Dependencies > Collect Files |
|
||||
| Swap an asset everywhere | Replace Footage > File |
|
||||
| Slim project | Reduce Project / Remove Unused Footage |
|
||||
| Run a script | File > Scripts > Run Script File... |
|
||||
| Pre-compose | Layer > Pre-compose (Ctrl/Cmd+Shift+C) |
|
||||
|
||||
## Gotchas
|
||||
|
||||
- **Collect Files before moving anything.** Moving the `.aep` alone always breaks links.
|
||||
- **Relinking one item often relinks the rest** from the same folder — try that before fixing each by hand.
|
||||
- **Replace Footage preserves effects/keyframes;** deleting + re-importing does not.
|
||||
- **AE auto-creates a "Solids" folder** — don't scatter solids elsewhere or it regenerates duplicates.
|
||||
- **Scripts need `app.beginUndoGroup`/`endUndoGroup`** or a batch becomes many separate undos.
|
||||
- **Applying effects by name needs the `matchName`,** not the display name (e.g., `"ADBE Gaussian Blur 2"`), to be reliable across AE language versions.
|
||||
- **Allow Scripts to Write Files** must be enabled in `Preferences > Scripting & Expressions` for scripts that save/render.
|
||||
- **Deep precomp nesting** makes both performance and relinking worse — keep it shallow.
|
||||
|
||||
---
|
||||
|
||||
# AE Project Organization — Detailed Reference
|
||||
|
||||
## Full folder (bin) template
|
||||
```
|
||||
PROJECT.aep
|
||||
├── 00_Output/ (final renders live next to project on disk)
|
||||
01_Comps/ master & active comps
|
||||
02_Precomps/ nested precomps (prefix PRE_)
|
||||
03_Footage/ video clips
|
||||
04_Images/ stills, logos, vector, textures
|
||||
05_Audio/ music, VO, SFX
|
||||
06_Solids/ AE auto-folder; leave it here
|
||||
07_Assets_3D/ OBJ/C4D/3D model assets
|
||||
08_Reference/ storyboards, briefs, temp ref
|
||||
99_Old/ deprecated, kept until final
|
||||
```
|
||||
Numeric prefixes lock sort order. Keep the on-disk asset folders mirroring these bins so Collect Files stays clean.
|
||||
|
||||
## Naming scheme
|
||||
| Item | Pattern | Example |
|
||||
|---|---|---|
|
||||
| Master comp | `PROJ_section_v##` | `BRAND_main_v04` |
|
||||
| Sub/shot comp | `PROJ_section_shot_v##` | `BRAND_intro_logo_v02` |
|
||||
| Precomp | `PRE_descriptor` | `PRE_textReveal` |
|
||||
| Null/control | `CTRL_role` | `CTRL_master` |
|
||||
| Solid/BG | `BG_role` | `BG_gradient` |
|
||||
| Matte | `MATTE_role` | `MATTE_logoTrack` |
|
||||
| Adjustment | `ADJ_role` | `ADJ_grade` |
|
||||
|
||||
Rules: zero-pad versions; no spaces/special characters for farm/cross-OS safety; keep unique and short.
|
||||
|
||||
## Label color system (example)
|
||||
| Color | Meaning |
|
||||
|---|---|
|
||||
| Red | Control / null layers |
|
||||
| Blue | Footage |
|
||||
| Green | Precomps |
|
||||
| Yellow | Text |
|
||||
| Purple | Adjustment / effects |
|
||||
| Orange | Audio |
|
||||
| Gray | Disabled / old |
|
||||
|
||||
Set via right-click → Label. Customize names/colors in `Preferences > Labels`. Use `Edit > Label > Select Label Group` to select everything of one color.
|
||||
|
||||
## Relink / missing footage — full workflow
|
||||
1. **Identify:** missing items show as colored bars with "Missing" placeholders; the Project panel marks them.
|
||||
2. **Relink one to fix many:** right-click a missing item → **Replace Footage > File** (or double-click it). Choose the relocated file. AE prompts to relink all other missing files found in the same folder — accept to fix the batch at once.
|
||||
3. **Enumerate:** `File > Dependencies > Find Missing Footage`, `Find Missing Fonts`, `Find Missing Effects` to locate every broken dependency.
|
||||
4. **Swap assets:** **Replace Footage > File** swaps the source while preserving all layer instances, effects, masks, and keyframes.
|
||||
|
||||
## Collect Files (portable handoff)
|
||||
- `File > Dependencies > Collect Files`.
|
||||
- Options: Collect Source Files = **All**; enable **Reduce Project** to drop unused; optionally **Generate Report**.
|
||||
- Produces a folder containing the `.aep` plus a `(Footage)` subfolder with every used asset, preserving relative links so the project opens anywhere.
|
||||
- Always deliver/move projects as a Collect Files package, never a lone `.aep`.
|
||||
|
||||
## Slimming a project
|
||||
- `File > Reduce Project` — removes all items not used by the currently selected comp(s). Destructive to unused items; save first.
|
||||
- `File > Dependencies > Consolidate All Footage` — merges duplicate imports of the same file.
|
||||
- `File > Dependencies > Remove Unused Footage` — drops footage no comp references.
|
||||
- Run these before Collect Files to keep the package small.
|
||||
|
||||
## Scripting setup
|
||||
- Enable `Preferences > Scripting & Expressions > Allow Scripts to Write Files and Access Network` for scripts that save or render.
|
||||
- Run a script: `File > Scripts > Run Script File...`.
|
||||
- Dock a panel script: place the `.jsx` in `(AE install)/Scripts/ScriptUI Panels/`, restart AE, open from the `Window` menu.
|
||||
- Wrap every batch in `app.beginUndoGroup("...")` / `app.endUndoGroup()` so it undoes in one step.
|
||||
- Apply effects by **matchName** (internal id like `"ADBE Gaussian Blur 2"`), not the localized display name, for cross-version reliability. Use `layer.property("ADBE Effect Parade").addProperty(matchName)`.
|
||||
|
||||
## Pre-comp discipline details
|
||||
- "Leave all attributes in the new composition" keeps the outer layer's transform; "Move all attributes" pushes them inside the precomp. Choosing wrong shifts/rescales the result.
|
||||
- Trim precomp duration to the content; over-long precomps waste RAM/disk cache.
|
||||
- Name and file precomps immediately; never leave "Pre-comp 1".
|
||||
- Keep nesting shallow (2–3 levels) for performance and easier relinking/debugging.
|
||||
|
||||
---
|
||||
Keep the project tidy and named well and footage relinks without a fight. Built by **[iart.ai](https://iart.ai/?utm_source=github&utm_medium=readme&utm_campaign=motion-design-skills&utm_content=skill_footer&utm_term=after-effects)** — the AI motion agent for editable, on-brand motion graphics.
|
||||
@@ -0,0 +1,49 @@
|
||||
/*
|
||||
* apply-effect-to-layers.jsx
|
||||
* Applies an effect (by internal matchName) to every selected layer.
|
||||
*
|
||||
* Why matchName: display names are localized and change between AE language
|
||||
* versions; matchName is stable. Examples:
|
||||
* "ADBE Gaussian Blur 2" -> Gaussian Blur
|
||||
* "ADBE Fast Box Blur" -> Fast Box Blur
|
||||
* "ADBE Tint" -> Tint
|
||||
* "ADBE Drop Shadow" -> Drop Shadow
|
||||
* "ADBE Glo2" -> Glow
|
||||
*
|
||||
* Usage: select layers in a comp, then File > Scripts > Run Script File...
|
||||
* Edit EFFECT_MATCHNAME (and the optional parameter block) below.
|
||||
*/
|
||||
|
||||
(function applyEffectToLayers() {
|
||||
var EFFECT_MATCHNAME = "ADBE Gaussian Blur 2";
|
||||
|
||||
var comp = app.project.activeItem;
|
||||
if (!(comp && comp instanceof CompItem)) {
|
||||
alert("Open a composition and select one or more layers first.");
|
||||
return;
|
||||
}
|
||||
|
||||
var sel = comp.selectedLayers;
|
||||
if (sel.length === 0) {
|
||||
alert("No layers selected.");
|
||||
return;
|
||||
}
|
||||
|
||||
app.beginUndoGroup("Apply Effect To Layers");
|
||||
try {
|
||||
for (var i = 0; i < sel.length; i++) {
|
||||
var layer = sel[i];
|
||||
if (!(layer instanceof AVLayer)) continue; // effects need an AVLayer
|
||||
|
||||
var effects = layer.property("ADBE Effect Parade");
|
||||
if (!effects.canAddProperty(EFFECT_MATCHNAME)) continue;
|
||||
|
||||
var fx = effects.addProperty(EFFECT_MATCHNAME);
|
||||
|
||||
// --- Optional: set a parameter. Example for Gaussian Blur radius ---
|
||||
// try { fx.property("Blurriness").setValue(25); } catch (e) {}
|
||||
}
|
||||
} finally {
|
||||
app.endUndoGroup();
|
||||
}
|
||||
})();
|
||||
@@ -0,0 +1,41 @@
|
||||
/*
|
||||
* batch-rename.jsx
|
||||
* Renames the selected layers in the active comp to: baseName_##
|
||||
* with a zero-padded, incrementing index.
|
||||
*
|
||||
* Usage: select layers in a comp, then File > Scripts > Run Script File...
|
||||
* Edit BASE_NAME, START_INDEX, and PAD below.
|
||||
*/
|
||||
|
||||
(function batchRename() {
|
||||
var BASE_NAME = "layer"; // base name applied to every selected layer
|
||||
var START_INDEX = 1; // first number
|
||||
var PAD = 2; // zero-padding width (2 -> 01, 02 ...)
|
||||
|
||||
var comp = app.project.activeItem;
|
||||
if (!(comp && comp instanceof CompItem)) {
|
||||
alert("Open a composition and select one or more layers first.");
|
||||
return;
|
||||
}
|
||||
|
||||
var sel = comp.selectedLayers;
|
||||
if (sel.length === 0) {
|
||||
alert("No layers selected.");
|
||||
return;
|
||||
}
|
||||
|
||||
function pad(n, width) {
|
||||
var s = String(n);
|
||||
while (s.length < width) s = "0" + s;
|
||||
return s;
|
||||
}
|
||||
|
||||
app.beginUndoGroup("Batch Rename Layers");
|
||||
try {
|
||||
for (var i = 0; i < sel.length; i++) {
|
||||
sel[i].name = BASE_NAME + "_" + pad(START_INDEX + i, PAD);
|
||||
}
|
||||
} finally {
|
||||
app.endUndoGroup();
|
||||
}
|
||||
})();
|
||||
@@ -0,0 +1,47 @@
|
||||
/*
|
||||
* sequential-offset.jsx
|
||||
* Staggers the selected layers in time so each starts OFFSET_FRAMES after
|
||||
* the previous one (a "domino" / cascade start), based on the first
|
||||
* selected layer's start time.
|
||||
*
|
||||
* Usage: select layers in a comp, then File > Scripts > Run Script File...
|
||||
* Edit OFFSET_FRAMES and ORDER below.
|
||||
*/
|
||||
|
||||
(function sequentialOffset() {
|
||||
var OFFSET_FRAMES = 2; // frames between each layer's start
|
||||
var ORDER_BY_SELECTION = true; // true = order of selection; false = by current startTime
|
||||
|
||||
var comp = app.project.activeItem;
|
||||
if (!(comp && comp instanceof CompItem)) {
|
||||
alert("Open a composition and select two or more layers first.");
|
||||
return;
|
||||
}
|
||||
|
||||
var sel = comp.selectedLayers;
|
||||
if (sel.length < 2) {
|
||||
alert("Select at least two layers.");
|
||||
return;
|
||||
}
|
||||
|
||||
var frameDur = comp.frameDuration; // seconds per frame
|
||||
var offsetSec = OFFSET_FRAMES * frameDur;
|
||||
|
||||
// Build the working order.
|
||||
var layers = [];
|
||||
for (var i = 0; i < sel.length; i++) layers.push(sel[i]);
|
||||
if (!ORDER_BY_SELECTION) {
|
||||
layers.sort(function (a, b) { return a.startTime - b.startTime; });
|
||||
}
|
||||
|
||||
var base = layers[0].startTime;
|
||||
|
||||
app.beginUndoGroup("Sequential Offset");
|
||||
try {
|
||||
for (var j = 0; j < layers.length; j++) {
|
||||
layers[j].startTime = base + (j * offsetSec);
|
||||
}
|
||||
} finally {
|
||||
app.endUndoGroup();
|
||||
}
|
||||
})();
|
||||
File renamed without changes.
@@ -0,0 +1,114 @@
|
||||
---
|
||||
name: animation-principles
|
||||
description: This skill should be used when the user asks to "make this animation feel natural", "fix motion that feels stiff/floaty/cheap", "my animation looks robotic", "choose an easing curve", "how do I use the Graph Editor", "add overshoot or bounce", "Easy Ease isn't enough", "make snappy motion", "pick a duration for this transition", "stagger a list animation", "sync animation to a beat", or "review motion for good timing". It is the tech-agnostic foundation for deciding how something should move.
|
||||
version: 0.1.0
|
||||
---
|
||||
|
||||
# Motion Principles
|
||||
|
||||
Decide how something should move so it feels right — independent of the tool used to build it. This skill answers timing, easing, spacing, weight, and rhythm. It does not pick a tech stack; it produces concrete numbers (durations, cubic-bezier curves, stagger offsets, spring configs) ready to hand to any implementation.
|
||||
|
||||
## When to use
|
||||
|
||||
- Motion feels stiff, floaty, mechanical, robotic, or cheap and needs diagnosis.
|
||||
- Choosing a clip or transition's duration, easing curve, and stagger offset.
|
||||
- Reviewing whether motion respects physics intuition (weight, follow-through, arcs).
|
||||
- Synchronizing keyframes to a musical beat or edit accent.
|
||||
|
||||
## Three pillars — settle these before any number
|
||||
|
||||
Every piece of motion should answer three questions *before* you pick a duration or curve. Skip them and you get technically-correct motion that feels like nothing. These are the shared vocabulary the rest of the collection refers back to.
|
||||
|
||||
| Pillar | The question | What it drives |
|
||||
|---|---|---|
|
||||
| **Emotional intent** | What should the viewer *feel*? (joy, calm, urgency, trust, elegance) | Easing, duration, amplitude/overshoot |
|
||||
| **Visual narrative** | What's the micro-story? Setup → action → resolution | Sequencing, staging, what enters when |
|
||||
| **Motion craft** | How do we make it believable? | Physics, secondary motion, arcs, follow-through |
|
||||
|
||||
## Three motion layers — depth, not flatness
|
||||
|
||||
Flat motion = only the main thing moves. Believable motion runs three layers at once:
|
||||
|
||||
- **Primary** — the main action the eye follows (the hero move).
|
||||
- **Secondary** — supporting richness reacting to the primary (a shadow shifting, an icon nudging, a label settling late).
|
||||
- **Ambient** — background life that never demands attention (slow gradient drift, a low-contrast pulse).
|
||||
|
||||
> The judgment layer (`motion-art-direction`) calls these **Hero / Support / Texture** — same three layers, ranked for *what earns motion*. Primary≈Hero, Secondary≈Support, Ambient≈Texture.
|
||||
|
||||
## Core principles
|
||||
|
||||
### Easing is the single biggest lever
|
||||
|
||||
Linear motion reads as robotic. Reserve `linear` for continuous loops (spinners, marquees, infinite scroll) only. Everything an eye perceives as a discrete event needs acceleration.
|
||||
|
||||
Match the curve to the action:
|
||||
- **Enter / appear** -> ease-out (fast start, gentle settle). Object arrives with energy and decelerates into place. `cubic-bezier(0.16, 1, 0.3, 1)`.
|
||||
- **Exit / disappear** -> ease-in (gentle start, fast end). Object accelerates away. `cubic-bezier(0.7, 0, 0.84, 0)`.
|
||||
- **Move / reposition (stays on screen)** -> ease-in-out (symmetric). `cubic-bezier(0.65, 0, 0.35, 1)`.
|
||||
- **Playful / branded** -> slight overshoot. `cubic-bezier(0.34, 1.56, 0.64, 1)` (the `1.56` pushes past 1.0, creating an overshoot-and-settle that reads as "weight").
|
||||
|
||||
Rule of thumb: the eye forgives a slow start far less than a slow end. When in doubt, decelerate into rest.
|
||||
|
||||
**Hand-shaping easing (After Effects).** When keyframing by hand rather than supplying a curve, the same principles map to the Graph Editor: shape the Speed Graph so the ends flatten toward zero, and push deceleration influence to 80–90% for a snappy launch and smooth settle. `F9` (Easy Ease) is only a 33% symmetric starting point — make it asymmetric. See `references/easing-graph-editor.md` for Graph Editor reading, handle/influence techniques, and step-by-step overshoot, anticipation, and bounce recipes (including a decaying-bounce expression).
|
||||
|
||||
### Timing communicates weight and importance
|
||||
|
||||
| Element | Duration |
|
||||
|---|---|
|
||||
| Micro-interaction (hover, toggle, tap feedback) | 100-200ms |
|
||||
| UI transition (panel, modal, page region) | 200-400ms |
|
||||
| Hero / large element / full-screen | 400-800ms |
|
||||
| Cinematic camera move | 800-2000ms |
|
||||
|
||||
Distance and size scale duration. A small icon moving 20px and a full-bleed panel moving 800px should NOT share a duration — the panel needs more time or it looks weightless. A practical scaling: keep perceived velocity roughly constant by adding ~30-50% duration when distance or area roughly doubles. Heavy objects start slowly and overshoot less; light objects snap and may bounce.
|
||||
|
||||
### Spacing and stagger create rhythm
|
||||
|
||||
Never reveal a list, grid, or group all at once — it reads as a single flat event. Stagger each child's start.
|
||||
|
||||
- Lists / sequential items: **40-80ms** between items.
|
||||
- Dense grids: **20-40ms** (more items, less per-item delay, or the tail drags).
|
||||
- Cap total reveal at roughly **600-800ms** for a group; if `count * offset` exceeds that, shrink the offset or switch to a distance-based stagger (items further from an origin point start later).
|
||||
- Stagger direction should follow the eye: top-to-bottom, or radiating from a focal point.
|
||||
|
||||
**The 1/3 Rule (two forms, both universal):**
|
||||
- *Distance* — no element travels more than ~1/3 of the screen without an intermediate keyframe or a scale/opacity change. Long unbroken slides read as "the template moved," not "something happened."
|
||||
- *Simultaneity* — with 3+ elements, keep no more than ~1/3 in active motion at once. The rest hold or move as ambient. Everything moving together = noise with no focal point.
|
||||
|
||||
### Anticipation and follow-through sell physical motion
|
||||
|
||||
- **Anticipation**: a tiny counter-move before the main action (a button dips `scale 0.95` before popping, a character crouches before jumping). 60-120ms is enough.
|
||||
- **Follow-through / overlapping action**: trailing parts keep moving after the main body stops (a hero card lands, then its shadow and label settle 40-80ms later). Stagger the settle of attached elements rather than stopping everything on the same frame.
|
||||
- **Arcs**: natural movement curves; pure straight-line translation of an organic object looks mechanical. Add a slight arc to x/y or animate a path.
|
||||
|
||||
### Beat-sync and rhythm
|
||||
|
||||
When motion accompanies audio, land impact keyframes (a hit, a cut, a reveal) on the beat, not between beats. At 120 BPM a beat is 500ms; an eighth-note grid is 250ms. Quantize key moments to that grid. For edits without music, establish a visual pulse (e.g. one major event per ~500-800ms) so the piece breathes consistently.
|
||||
|
||||
### Spring vs. duration-based motion
|
||||
|
||||
Springs (mass / stiffness / damping) self-determine duration and feel more physical for interactive, interruptible motion (drag-release, gestures). Duration+easing is better for choreographed, timeline-locked sequences (video, scroll-tied reveals) where exact sync matters. A snappy default spring: `stiffness 300, damping 30, mass 1`. See `references/easing-curves.md` for a full spring table.
|
||||
|
||||
## Diagnosing common failures
|
||||
|
||||
- **Feels stiff/robotic** -> using `linear` or symmetric easing on an enter; switch to ease-out.
|
||||
- **Feels floaty/sluggish** -> duration too long or ease-out too gentle; cut duration 30%, sharpen the curve.
|
||||
- **Feels cheap/janky** -> everything appears at once (no stagger), or all elements share one duration regardless of size.
|
||||
- **Feels mechanical despite easing** -> no anticipation, no follow-through, straight-line paths; add arcs and overlap.
|
||||
|
||||
## Quick reference
|
||||
|
||||
| Need | Use |
|
||||
|---|---|
|
||||
| Enter | `cubic-bezier(0.16, 1, 0.3, 1)`, 300-500ms |
|
||||
| Exit | `cubic-bezier(0.7, 0, 0.84, 0)`, 200-300ms |
|
||||
| Move | `cubic-bezier(0.65, 0, 0.35, 1)`, 300-400ms |
|
||||
| Branded pop | `cubic-bezier(0.34, 1.56, 0.64, 1)`, 400-600ms |
|
||||
| List stagger | 40-80ms per item, cap ~700ms total |
|
||||
| Loop only | `linear` |
|
||||
|
||||
## Reference files
|
||||
|
||||
- `references/easing-curves.md` — named cubic-bezier library with exact values, spring configs (Framer/react-spring/iOS), and per-element-type duration guidance.
|
||||
- `references/easing-graph-editor.md` — After Effects Graph Editor craft: speed graph vs value graph, easing handles and influence/velocity numbers, and step-by-step snappy, overshoot, anticipation, and bounce recipes.
|
||||
- `references/twelve-principles.md` — all 12 Disney principles, each with a concrete, numeric motion-graphics example.
|
||||
@@ -0,0 +1,136 @@
|
||||
# Easing curves, springs, and durations
|
||||
|
||||
A reference library of exact values. Copy directly.
|
||||
|
||||
## Named cubic-bezier library
|
||||
|
||||
These are battle-tested curves. The four numbers are `(x1, y1, x2, y2)` control points.
|
||||
|
||||
### Ease-out family (use for ENTER / appear / settle)
|
||||
|
||||
| Name | cubic-bezier | Feel |
|
||||
|---|---|---|
|
||||
| easeOutQuad | `0.5, 1, 0.89, 1` | gentle, subtle |
|
||||
| easeOutCubic | `0.33, 1, 0.68, 1` | balanced, safe default |
|
||||
| easeOutQuart | `0.25, 1, 0.5, 1` | snappy |
|
||||
| easeOutQuint | `0.22, 1, 0.36, 1` | very snappy, decisive |
|
||||
| easeOutExpo | `0.16, 1, 0.3, 1` | dramatic, "premium" arrival |
|
||||
| easeOutCirc | `0, 0.55, 0.45, 1` | strong late deceleration |
|
||||
|
||||
### Ease-in family (use for EXIT / disappear / accelerate away)
|
||||
|
||||
| Name | cubic-bezier | Feel |
|
||||
|---|---|---|
|
||||
| easeInQuad | `0.11, 0, 0.5, 0` | gentle pull-away |
|
||||
| easeInCubic | `0.32, 0, 0.67, 0` | balanced exit |
|
||||
| easeInQuart | `0.5, 0, 0.75, 0` | sharp exit |
|
||||
| easeInExpo | `0.7, 0, 0.84, 0` | dramatic, fast vanish |
|
||||
|
||||
### Ease-in-out family (use for MOVE / reposition while on screen)
|
||||
|
||||
| Name | cubic-bezier | Feel |
|
||||
|---|---|---|
|
||||
| easeInOutQuad | `0.45, 0, 0.55, 1` | smooth, neutral |
|
||||
| easeInOutCubic | `0.65, 0, 0.35, 1` | balanced default |
|
||||
| easeInOutQuart | `0.76, 0, 0.24, 1` | punchy in and out |
|
||||
| easeInOutExpo | `0.87, 0, 0.13, 1` | very dramatic, long hold mid |
|
||||
|
||||
### Overshoot / back family (use for PLAYFUL / branded / "weighty")
|
||||
|
||||
| Name | cubic-bezier | Notes |
|
||||
|---|---|---|
|
||||
| easeOutBack | `0.34, 1.56, 0.64, 1` | overshoots past target then settles |
|
||||
| easeInBack | `0.36, 0, 0.66, -0.56` | dips below before launching (anticipation) |
|
||||
| easeInOutBack | `0.68, -0.6, 0.32, 1.6` | anticipate + overshoot |
|
||||
|
||||
The `y` value above 1 (e.g. `1.56`) or below 0 (e.g. `-0.56`) is what creates overshoot/anticipation. Bigger excursion = more bounce.
|
||||
|
||||
## Material Design standard curves (good for product UI)
|
||||
|
||||
| Token | cubic-bezier | Use |
|
||||
|---|---|---|
|
||||
| Standard | `0.2, 0, 0, 1` | most transitions |
|
||||
| Decelerate (enter) | `0, 0, 0, 1` | elements entering screen |
|
||||
| Accelerate (exit) | `0.3, 0, 1, 1` | elements leaving screen |
|
||||
| Emphasized | `0.2, 0, 0, 1` (300-500ms) | hero moments |
|
||||
|
||||
## iOS / Apple feel
|
||||
|
||||
Apple favors springs, but the closest bezier is `0.25, 0.1, 0.25, 1` (the legacy `ease`) sharpened toward `0.33, 1, 0.68, 1`. For modal presentation Apple uses a spring close to `stiffness 280, damping 28`.
|
||||
|
||||
## Spring configurations
|
||||
|
||||
Springs are defined by stiffness (tension), damping (friction), and mass. Higher stiffness = faster; higher damping = less bounce; higher mass = more sluggish/heavy.
|
||||
|
||||
### Framer Motion (`type: "spring"`)
|
||||
|
||||
```js
|
||||
// Snappy default — interactive UI
|
||||
{ type: "spring", stiffness: 300, damping: 30, mass: 1 }
|
||||
|
||||
// Bouncy — playful, branded
|
||||
{ type: "spring", stiffness: 400, damping: 17, mass: 1 }
|
||||
|
||||
// Gentle — large/heavy elements, modals
|
||||
{ type: "spring", stiffness: 120, damping: 20, mass: 1 }
|
||||
|
||||
// Stiff/no bounce — precise, critically damped
|
||||
{ type: "spring", stiffness: 500, damping: 50, mass: 1 }
|
||||
|
||||
// Alternative API: duration-based spring (Framer Motion v10+)
|
||||
{ type: "spring", duration: 0.5, bounce: 0.25 } // bounce 0 = no overshoot, 0.5 = lively
|
||||
```
|
||||
|
||||
### react-spring presets
|
||||
|
||||
```js
|
||||
import { config } from '@react-spring/web'
|
||||
config.default // { tension: 170, friction: 26 }
|
||||
config.gentle // { tension: 120, friction: 14 }
|
||||
config.wobbly // { tension: 180, friction: 12 } — visible bounce
|
||||
config.stiff // { tension: 210, friction: 20 }
|
||||
config.slow // { tension: 280, friction: 60 } — heavy, no bounce
|
||||
config.molasses // { tension: 280, friction: 120 }
|
||||
```
|
||||
|
||||
### SwiftUI / iOS
|
||||
|
||||
```swift
|
||||
.spring(response: 0.4, dampingFraction: 0.8) // response = approx duration, dampingFraction 1.0 = no bounce
|
||||
.interactiveSpring() // for gesture-driven
|
||||
```
|
||||
|
||||
## Duration guidance per element type
|
||||
|
||||
| Element / event | Duration | Easing |
|
||||
|---|---|---|
|
||||
| Hover state, tap highlight | 100-150ms | easeOutQuad |
|
||||
| Toggle, checkbox, switch | 150-200ms | easeOutCubic |
|
||||
| Tooltip, dropdown open | 150-250ms | easeOutCubic |
|
||||
| Button press feedback | 80-120ms down / 200ms up | easeOut + back on release |
|
||||
| Modal / dialog enter | 300-400ms | easeOutExpo or spring(gentle) |
|
||||
| Modal / dialog exit | 200-250ms | easeInQuart |
|
||||
| Page / route region transition | 300-500ms | easeInOutCubic |
|
||||
| Card / list item reveal | 400-500ms each | easeOutExpo |
|
||||
| Hero headline / full-screen | 500-800ms | easeOutExpo |
|
||||
| Cinematic camera push/pan | 800-2000ms | easeInOutQuad |
|
||||
| Loading spinner | continuous | linear |
|
||||
| Number count-up | 600-1200ms | easeOutExpo |
|
||||
|
||||
## Distance-to-duration scaling
|
||||
|
||||
To keep perceived velocity natural, scale duration with travel distance:
|
||||
|
||||
```
|
||||
duration_ms ≈ base_ms * (distance_px / base_distance_px) ^ 0.5
|
||||
```
|
||||
|
||||
The `^0.5` (square root) prevents long moves from feeling tediously slow while still granting them more time than short moves. Example: base 300ms at 200px -> a 800px move ≈ 300 * sqrt(4) = 600ms.
|
||||
|
||||
## Stagger math
|
||||
|
||||
```
|
||||
total = (count - 1) * offset + per_item_duration
|
||||
```
|
||||
|
||||
Keep `total` under ~800ms for group reveals. If it exceeds that, reduce `offset` or use distance-based staggering (each item's delay proportional to its distance from a focal origin), which keeps a constant feel regardless of count.
|
||||
@@ -0,0 +1,153 @@
|
||||
# Easing in the After Effects Graph Editor
|
||||
|
||||
Tool-specific craft for turning the abstract easing principles into hand-shaped After Effects keyframes. The concepts here (slow-in/slow-out, asymmetric easing, overshoot, bounce) apply everywhere; the controls are AE's Graph Editor.
|
||||
|
||||
## The principle: slow-in / slow-out
|
||||
|
||||
Natural motion accelerates from rest and decelerates to rest — "slow-in, slow-out". Constant-speed (linear) motion reads as robotic because nothing physical starts and stops instantly. Easing means shaping how fast a property changes over time, not just its start and end values.
|
||||
|
||||
## Graph Editor basics
|
||||
|
||||
Open with the **Graph Editor** button (the curve icon) in the Timeline (or Shift+F3). It replaces the keyframe strip with curves.
|
||||
|
||||
Two graph modes, switched via the **graph type menu** at the bottom of the Graph Editor:
|
||||
|
||||
- **Value Graph** — plots the property's value over time (e.g., X position in pixels). The line's height = the value; its slope = the speed.
|
||||
- **Speed Graph** — plots the rate of change (speed) over time. The line's height = speed; a hump = fast, a valley near zero = slow/stopped.
|
||||
|
||||
**How to tell which is shown:** Open the graph type menu → "Edit Value Graph" / "Edit Speed Graph" shows the current choice (the active one is checked). Quick tell: for a single moving property, the **Speed Graph** reads as a hill (accelerate up, decelerate down); the **Value Graph** reads as an S-curve climbing from start value to end value. Spatial properties (Position) usually default to the Speed Graph; single-dimension properties to the Value Graph.
|
||||
|
||||
For shaping ease feel, the **Speed Graph** is the most intuitive: flatten the ends toward zero (slow start/stop), let the middle rise (fast).
|
||||
|
||||
### Display tips
|
||||
- Enable "Show Reference Graph" to see the other graph faintly behind the editable one.
|
||||
- "Snap" and "Fit selection to view" make handle work easier.
|
||||
|
||||
## Why Easy Ease is rarely enough
|
||||
|
||||
`F9` (Easy Ease) applies a symmetric ease with ~33% influence on both sides. It's a starting point, not a finished move. Two reasons it falls flat:
|
||||
|
||||
1. **Symmetry.** Most compelling motion is asymmetric — e.g., snappy UI eases *out* hard (fast start, long glide to stop) far more than it eases in.
|
||||
2. **Low influence.** 33% is gentle. Strong, modern motion-design easing pushes influence to **80–90%** on the deceleration side, producing a sharp launch and a smooth settle.
|
||||
|
||||
So: start with `F9`, then open the Graph Editor and **drag the bezier handles** to make it asymmetric and increase influence.
|
||||
|
||||
## Handle techniques
|
||||
|
||||
In the Graph Editor each keyframe has bezier handles:
|
||||
|
||||
- **Pull a handle horizontally (longer)** → more influence → the ease extends further in time → smoother, slower approach.
|
||||
- **Pull a handle down toward zero speed** → the property comes more fully to rest at that keyframe.
|
||||
- **Ease out 80–90%:** select the final keyframe, drag its incoming handle nearly flat and long so speed glides to near-zero over most of the move. This is the core "snappy" feel.
|
||||
- **Overshoot:** let the value go past the target, then settle back. In the Value Graph, push the curve above the end value briefly, then return. Or add a small keyframe past the target and ease back.
|
||||
- **Bounce:** repeated decaying overshoots — the value hits, overshoots less each time, settling. Build with successive keyframes of decreasing amplitude, each eased.
|
||||
|
||||
## Influence and velocity numbers
|
||||
|
||||
Right-click a keyframe → **Keyframe Velocity** to set exact values:
|
||||
|
||||
- **Incoming/Outgoing Velocity** — the speed at the keyframe (units/sec). Zero = full stop.
|
||||
- **Influence %** — how far the ease extends toward the neighboring keyframe. Higher = smoother, longer ease.
|
||||
|
||||
Targets:
|
||||
- Snappy UI move: outgoing influence ~15–25% (quick launch), **incoming influence 80–90%** (long settle).
|
||||
- Smooth symmetric float: both sides ~50–65%.
|
||||
- Anticipation: a small reverse move before the main action (pull back, then go).
|
||||
|
||||
## Recipe table
|
||||
|
||||
| Feel | Speed Graph shape | Outgoing inf. | Incoming inf. | Notes |
|
||||
|---|---|---|---|---|
|
||||
| Snappy UI | sharp rise, long tail to 0 | 10–25% | 80–90% | The default "good" motion-design ease |
|
||||
| Smooth float | gentle symmetric hill | 50–65% | 50–65% | Calm, even, no snap |
|
||||
| Anticipation | dip below 0 then rise | add pre-keyframe | 70–85% | Tiny reverse move first |
|
||||
| Overshoot | rise, overshoot value, settle | 20–40% | 85–95% | 1 extra keyframe past target |
|
||||
| Bounce | repeated decaying humps | per-bounce | per-bounce | Decreasing amplitude keyframes |
|
||||
|
||||
## Quick reference
|
||||
|
||||
| Action | How |
|
||||
|---|---|
|
||||
| Open Graph Editor | Curve icon in Timeline (or Shift+F3) |
|
||||
| Apply Easy Ease | `F9` (Ease In `Shift+F9`, Ease Out `Ctrl/Cmd+Shift+F9`) |
|
||||
| Switch Value/Speed graph | Graph type menu (bottom of Graph Editor) |
|
||||
| Set exact velocity | Right-click keyframe → Keyframe Velocity |
|
||||
| Convert to bezier handles | Easy Ease, then drag handles |
|
||||
| Strong settle | Incoming influence 80–90% on last keyframe |
|
||||
|
||||
## Step-by-step recipes
|
||||
|
||||
### Snappy UI ease (the workhorse)
|
||||
1. Set two Position (or Scale) keyframes for the move.
|
||||
2. Select both, press `F9` (Easy Ease).
|
||||
3. Open Graph Editor → Speed Graph.
|
||||
4. Select the **first** keyframe; shorten its outgoing handle (low influence, ~15–25%) so it launches fast.
|
||||
5. Select the **last** keyframe; pull its incoming handle long and nearly flat to the time axis — influence **80–90%** — so it glides to a stop.
|
||||
6. Result: fast start, long smooth settle. This is the standard "premium" motion-design feel.
|
||||
|
||||
Exact via Keyframe Velocity (right-click keyframe):
|
||||
- First keyframe: Outgoing influence 18%, velocity 0.
|
||||
- Last keyframe: Incoming influence 85%, velocity 0.
|
||||
|
||||
### Overshoot
|
||||
Goal: element flies in, slightly passes its target, settles back.
|
||||
1. Animate from start to target value (2 keyframes), ease.
|
||||
2. Add a **third keyframe ~6–10 frames before** the final, set its value **past** the target (e.g., target 100% → set 112%).
|
||||
3. Final keyframe returns to target (100%).
|
||||
4. Ease all keyframes; give the settle keyframes high incoming influence (85–95%).
|
||||
5. Tune overshoot amount (how far past) and settle time for snappiness.
|
||||
|
||||
Value Graph view: the curve rises above the target line, then dips back down to it.
|
||||
|
||||
### Anticipation
|
||||
Goal: a small reverse move before the main action (wind-up).
|
||||
1. Before the main motion's first keyframe, add a keyframe that moves **slightly opposite** the main direction (e.g., a jump-up preceded by a small crouch-down).
|
||||
2. Ease the wind-up gently, then the main move fast (low outgoing influence).
|
||||
3. Optionally combine with overshoot on the landing for a full squash-stretch feel.
|
||||
|
||||
### Bounce (hand-keyed)
|
||||
1. First keyframe: rest/start.
|
||||
2. Impact keyframe: the object hits the floor value.
|
||||
3. Bounce keyframes: each successive peak is **lower** than the last (decaying amplitude), spaced **closer** in time (decreasing period).
|
||||
4. At each floor contact, set incoming/outgoing velocity sharp (near-instant direction change); at each peak, ease to near-zero speed (apex).
|
||||
5. 3–4 decaying bounces usually read as natural.
|
||||
|
||||
Amplitude example for a drop settling to 0: 0 → -200 (rise) → 0 → -90 → 0 → -35 → 0 → -12 → 0, with shrinking time gaps.
|
||||
|
||||
### Bounce (expression)
|
||||
Apply to a property (e.g., Position) after a single ease-in keyframe to auto-generate decaying bounce:
|
||||
```javascript
|
||||
amp = 0.12; // bounce strength
|
||||
freq = 2.5; // bounces per second
|
||||
decay = 5.0; // how fast it settles
|
||||
n = 0;
|
||||
if (numKeys > 0) { n = nearestKey(time).index; if (key(n).time > time) n--; }
|
||||
if (n > 0) {
|
||||
t = time - key(n).time;
|
||||
v = velocityAtTime(key(n).time - thisComp.frameDuration/10);
|
||||
value + v*(amp*Math.sin(freq*t*2*Math.PI)/Math.exp(decay*t));
|
||||
} else { value; }
|
||||
```
|
||||
- `amp` raises the overshoot height; `freq` the number of wobbles; `decay` how quickly it stops.
|
||||
- Place a single eased keyframe (or two) where the motion arrives; the expression adds the bounce after.
|
||||
|
||||
## Velocity / influence cheat sheet
|
||||
|
||||
| Feel | Out influence | In influence | Velocity at stops |
|
||||
|---|---|---|---|
|
||||
| Snappy UI | 15–25% | 80–90% | 0 |
|
||||
| Smooth float | 50–65% | 50–65% | 0 |
|
||||
| Mechanical/linear | 0% | 0% | constant |
|
||||
| Overshoot settle | 20–40% | 85–95% | 0 at final |
|
||||
| Bounce apex | high | high | 0 at apex |
|
||||
| Bounce impact | low | low | sharp/non-zero |
|
||||
|
||||
## Gotchas
|
||||
|
||||
- **Easy Ease ≠ finished.** It's a 33% symmetric starting point; almost always refine in the Graph Editor.
|
||||
- **Know your graph.** Editing a Value Graph thinking it's a Speed Graph produces confusing results — confirm in the graph type menu.
|
||||
- **Influence is per-side.** Asymmetric influence (low out, high in) is what makes UI motion feel snappy.
|
||||
- **Spatial vs temporal.** Position has both a motion path (spatial bezier in the Composition viewer) and speed easing (Graph Editor). A floaty arc may be a spatial handle issue, not temporal. Right-click a Position keyframe for **Rove Across Time** and spatial interpolation (Linear/Auto/Continuous Bezier).
|
||||
- **Auto-Bezier roving keyframes** can smooth speed across multiple keyframes but remove precise per-keyframe timing — use deliberately.
|
||||
- **Overshoot needs room past the target** — clamp/limits or layout edges can hide it.
|
||||
- **Bounce by hand is tedious;** expression-driven bounce (decaying sine) is common, but hand-keyed gives the most control.
|
||||
@@ -0,0 +1,82 @@
|
||||
# The 12 principles of animation, applied to motion graphics
|
||||
|
||||
The Disney principles, translated to UI/motion-graphics with concrete numeric examples. Ordered by how often they matter in screen motion (most-used first).
|
||||
|
||||
## 1. Slow in and slow out (easing)
|
||||
|
||||
The most important. Objects accelerate and decelerate; they don't snap to constant velocity.
|
||||
|
||||
Example: a card sliding in from the right travels 600px over 450ms with `cubic-bezier(0.16, 1, 0.3, 1)` (easeOutExpo) — fast at first, settling gently into place.
|
||||
|
||||
## 2. Timing
|
||||
|
||||
Number of frames / duration defines weight and mood. Fast = light/urgent, slow = heavy/calm.
|
||||
|
||||
Example: a 24px notification badge pops in over 150ms; a full-screen onboarding panel slides over 500ms. Same easing, different timing communicates different mass.
|
||||
|
||||
## 3. Follow-through and overlapping action
|
||||
|
||||
Parts don't all stop at once; trailing elements continue and settle after the lead.
|
||||
|
||||
Example: a hero card lands at 400ms; its drop-shadow finishes settling at 450ms, its title text at 460ms, its subtitle at 500ms — a 40-60ms cascade rather than a synchronized stop.
|
||||
|
||||
## 4. Anticipation
|
||||
|
||||
A small opposite move telegraphs the main action.
|
||||
|
||||
Example: a "send" button scales to `0.95` over 80ms (the dip), then springs to `1.0` and the message launches. Or a modal dips `y: +8px` for 60ms before sliding up — the recoil makes the launch feel powered.
|
||||
|
||||
## 5. Staging (focal direction)
|
||||
|
||||
Direct attention to one thing at a time; the motion makes the important element unambiguous.
|
||||
|
||||
Example: dim background to 40% opacity over 200ms while the target element scales `0.9 -> 1.0` and brightens — the eye has exactly one place to land.
|
||||
|
||||
## 6. Arcs
|
||||
|
||||
Natural movement follows curved paths, not straight lines.
|
||||
|
||||
Example: a floating action button moving from bottom-right to center-screen animates along a quadratic bezier path instead of a diagonal line; the slight arc reads as organic rather than mechanical.
|
||||
|
||||
## 7. Squash and stretch
|
||||
|
||||
Volume-preserving deformation conveys impact and elasticity.
|
||||
|
||||
Example: a bouncing dot stretches `scaleY 1.2 / scaleX 0.85` at the top of its arc and squashes `scaleY 0.8 / scaleX 1.15` on landing impact. Keep the product of scales ≈ 1 to preserve perceived volume. Use sparingly in product UI; common in playful loaders and mascots.
|
||||
|
||||
## 8. Exaggeration
|
||||
|
||||
Push the key pose beyond literal realism for clarity and appeal.
|
||||
|
||||
Example: a success checkmark overshoots to `scale 1.15` before settling to `1.0` (using easeOutBack `0.34, 1.56, 0.64, 1`); the overshoot makes success feel emphatic.
|
||||
|
||||
## 9. Secondary action
|
||||
|
||||
A subordinate motion supporting the primary one.
|
||||
|
||||
Example: while a panel slides up (primary), its icon rotates 90deg and a subtle particle shimmer fades in (secondary) — supporting, never competing for attention.
|
||||
|
||||
## 10. Straight-ahead vs. pose-to-pose
|
||||
|
||||
Pose-to-pose (define keyframes, interpolate between) is the norm for choreographed motion graphics; straight-ahead (frame-by-frame, momentum-driven) suits chaotic/organic effects like particles, smoke, and procedural noise.
|
||||
|
||||
Example: a logo build is pose-to-pose (start pose, end pose, eased between); a confetti burst is straight-ahead/physics-driven.
|
||||
|
||||
## 11. Solid drawing (depth and weight)
|
||||
|
||||
Maintain consistent perspective, volume, and lighting so motion respects 3D space.
|
||||
|
||||
Example: when a 2.5D card tilts on hover (`rotateY 8deg`), its shadow shifts and lengthens consistently and a subtle specular highlight sweeps — selling that it's a solid object catching light, not a flat sticker.
|
||||
|
||||
## 12. Appeal
|
||||
|
||||
The composite charm — clean silhouettes, confident timing, no jank. Achieved by applying the other 11 with restraint: correct easing, deliberate timing, follow-through, a touch of overshoot, and removing anything that competes.
|
||||
|
||||
Example: a polished toggle = 180ms easeOutCubic slide, a 40ms follow-through on the label color, a hairline overshoot on the knob — small, coherent, satisfying.
|
||||
|
||||
## Practical priority for screen motion
|
||||
|
||||
For most product/web work, nailing **slow-in/slow-out, timing, follow-through, anticipation, staging, and arcs** delivers 90% of the quality. Squash/stretch, exaggeration, and secondary action add personality where the brand calls for it.
|
||||
|
||||
---
|
||||
Apply the twelve principles with restraint and UI motion reads as intentional. Built by **[iart.ai](https://iart.ai/?utm_source=github&utm_medium=readme&utm_campaign=motion-design-skills&utm_content=skill_footer&utm_term=animation-principles)** — the AI motion agent for editable, on-brand motion graphics.
|
||||
@@ -1,179 +0,0 @@
|
||||
---
|
||||
name: ascii-animation
|
||||
description: This skill should be used when the user asks to "make an ASCII animation", "build a terminal/CLI intro or loader", "convert an image or video to ASCII art", "add an ASCII shader/post-effect to a canvas or Three.js scene", "create retro/hacker text-character motion", or "animate text characters with a brightness ramp". Covers generative ASCII fields, image/video/3D-to-ASCII, and animated character art for both web and terminal.
|
||||
version: 0.1.0
|
||||
---
|
||||
|
||||
# ASCII Animation
|
||||
|
||||
Render motion entirely with text characters. ASCII output is extremely lightweight, distinctive, and works in browsers (`<pre>`/canvas), terminals (ANSI), and over any 3D scene (Three.js `AsciiEffect`).
|
||||
|
||||
## When to use
|
||||
|
||||
- Build terminal/CLI intros, loaders, banners, or a retro/hacker aesthetic.
|
||||
- Convert an image, video frame, or 3D scene into animated ASCII.
|
||||
- Add an ASCII post-effect over an existing canvas/WebGL render.
|
||||
- Create generative text fields (plasma, sine waves, noise, tunnels).
|
||||
|
||||
## Core concept: the brightness ramp
|
||||
|
||||
Map luminance (0..1) to a character whose ink density matches. Order characters dark-to-light. Pick the index with `Math.round(lum * (ramp.length - 1))`.
|
||||
|
||||
Common ramps (dark to light):
|
||||
- Short (10): ` .:-=+*#%@`
|
||||
- Medium (16): ` .'\`^",:;Il!i><~+_-?][}{1)(|/tfjrxnuvczXYUJCLQ0OZmwqpdbkhao*#MW&8%B@$` truncated — see table below.
|
||||
- Standard 70-level (Paul Bourke), best for photos:
|
||||
`` $@B%8&WM#*oahkbdpqwmZO0QLCJUYXzcvunxrjft/\|()1{}[]?-_+~<>i!lI;:,"^`'. `` (reverse for dark-on-light).
|
||||
|
||||
Compute relative luminance from sRGB (perceptual):
|
||||
```js
|
||||
const lum = (0.2126 * r + 0.7152 * g + 0.0722 * b) / 255; // 0..1
|
||||
```
|
||||
|
||||
Invert when drawing dark text on a light background: `lum = 1 - lum`.
|
||||
|
||||
## Character cell aspect correction (the #1 gotcha)
|
||||
|
||||
Monospace character cells are taller than wide — roughly **0.5 width:height**. Sampling a square pixel grid produces a vertically stretched image. Correct by sampling **fewer rows than columns**: for a target of `cols` characters wide, use `rows = Math.round(cols * (imgH / imgW) * fontAspect)` where `fontAspect ≈ 0.5`. Equivalently, when drawing to an offscreen canvas, set its height to `cols * aspect * 0.5`.
|
||||
|
||||
## Web rendering: `<pre>` vs canvas
|
||||
|
||||
- **`<pre>` + textContent**: simplest. One string with `\n` per row. Fine up to ~120×60 chars at 30fps. Set `white-space: pre; font-family: monospace; line-height: 1;`.
|
||||
- **Canvas `fillText`**: needed for per-character color, larger grids, or 60fps. Draw each char at `x * cellW, y * cellH`. Faster than thousands of DOM nodes.
|
||||
|
||||
Generative `<pre>` field (plasma):
|
||||
```js
|
||||
const pre = document.querySelector('pre');
|
||||
const COLS = 100, ROWS = 50, ramp = ' .:-=+*#%@';
|
||||
function frame(t) {
|
||||
let out = '';
|
||||
for (let y = 0; y < ROWS; y++) {
|
||||
for (let x = 0; x < COLS; x++) {
|
||||
const v = Math.sin(x * 0.2 + t * 0.001)
|
||||
+ Math.sin(y * 0.3 + t * 0.0013)
|
||||
+ Math.sin((x + y) * 0.15 + t * 0.0007);
|
||||
const lum = (v + 3) / 6; // normalize -3..3 to 0..1
|
||||
out += ramp[Math.round(lum * (ramp.length - 1))];
|
||||
}
|
||||
out += '\n';
|
||||
}
|
||||
pre.textContent = out;
|
||||
requestAnimationFrame(frame);
|
||||
}
|
||||
requestAnimationFrame(frame);
|
||||
```
|
||||
|
||||
## Image / video to ASCII
|
||||
|
||||
Draw the source to a small offscreen canvas at `cols × rows`, read pixels with `getImageContext().getImageData`, then map each pixel to a character. For video, repeat per frame from a `<video>` element.
|
||||
|
||||
```js
|
||||
function videoToAscii(video, cols = 120) {
|
||||
const aspect = video.videoHeight / video.videoWidth;
|
||||
const rows = Math.round(cols * aspect * 0.5); // cell aspect correction
|
||||
const cv = document.createElement('canvas');
|
||||
cv.width = cols; cv.height = rows;
|
||||
const ctx = cv.getContext('2d', { willReadFrequently: true });
|
||||
const ramp = ' .:-=+*#%@', pre = document.querySelector('pre');
|
||||
(function tick() {
|
||||
ctx.drawImage(video, 0, 0, cols, rows);
|
||||
const { data } = ctx.getImageData(0, 0, cols, rows);
|
||||
let out = '';
|
||||
for (let i = 0; i < data.length; i += 4) {
|
||||
const lum = (0.2126*data[i] + 0.7152*data[i+1] + 0.0722*data[i+2]) / 255;
|
||||
out += ramp[Math.round(lum * (ramp.length - 1))];
|
||||
if (((i / 4) + 1) % cols === 0) out += '\n';
|
||||
}
|
||||
pre.textContent = out;
|
||||
requestAnimationFrame(tick);
|
||||
})();
|
||||
}
|
||||
```
|
||||
|
||||
For Node image→ASCII, see `scripts/img-to-ascii.mjs`.
|
||||
|
||||
## 3D-to-ASCII with Three.js
|
||||
|
||||
`AsciiEffect` wraps a renderer and renders any scene as ASCII into a DOM element. Render through the effect, not the renderer.
|
||||
|
||||
```js
|
||||
import { AsciiEffect } from 'three/addons/effects/AsciiEffect.js';
|
||||
const effect = new AsciiEffect(renderer, ' .:-=+*#%@', { invert: true });
|
||||
effect.setSize(innerWidth, innerHeight);
|
||||
effect.domElement.style.color = '#0f0';
|
||||
effect.domElement.style.backgroundColor = 'black';
|
||||
document.body.appendChild(effect.domElement);
|
||||
// in loop: effect.render(scene, camera); // NOT renderer.render
|
||||
```
|
||||
|
||||
## Terminal / CLI animation
|
||||
|
||||
Loop with ANSI escape codes: hide the cursor, move to home, print the frame, throttle to 12–24 fps. Show the cursor again on exit.
|
||||
|
||||
```js
|
||||
const ESC = '\x1b[';
|
||||
process.stdout.write(ESC + '?25l'); // hide cursor
|
||||
function frame(t) {
|
||||
process.stdout.write(ESC + 'H'); // cursor to top-left
|
||||
// build and write rows...
|
||||
}
|
||||
const id = setInterval(() => frame(Date.now()), 1000 / 20);
|
||||
process.on('SIGINT', () => {
|
||||
clearInterval(id);
|
||||
process.stdout.write(ESC + '?25h' + ESC + '2J'); // show cursor, clear
|
||||
process.exit();
|
||||
});
|
||||
```
|
||||
Use `ESC + '2J'` to clear the whole screen, `ESC + 'H'` for home (cheaper per frame than clearing). Color with `\x1b[38;2;R;G;Bm` (truecolor) and reset with `\x1b[0m`.
|
||||
|
||||
## Deliver & verify (standalone HTML)
|
||||
|
||||
> **Packaged helper** (`scripts/`): `scripts/seek-shot.sh anim.html 0 1.5 3` freezes the `?t=N` harness and screenshots each moment; `scripts/contact-sheet.sh sheet.png frame-*.png` tiles them for one-glance review. See `scripts/README.md`.
|
||||
|
||||
For a self-contained web ASCII piece (generative field, image/video→ASCII, `AsciiEffect` scene) the deliverable is **one HTML file that opens directly in a browser** — the `<pre>`/canvas, the ramp, and the rAF loop inline (Three.js from CDN if used). No build step. One file is the right tier; don't reach for a bundler. (Terminal/CLI pieces verify differently — capture stdout or a screenshot of the terminal.)
|
||||
|
||||
**Output contract:**
|
||||
- One `.html` file: the render target, the brightness ramp, and the `requestAnimationFrame` loop in one inline `<script>`.
|
||||
- Drive frames from an **injectable time** (not `Date.now()`/`performance.now()` directly) and seed any randomness, so a frame is reproducible.
|
||||
|
||||
**Seek harness — freeze the rAF loop on a deterministic frame.** `?t=N` renders exactly one frame at simulated time `N` instead of looping, so a screenshot is reproducible. Feed `N` where the loop reads time, and fix the seed:
|
||||
|
||||
```html
|
||||
<script>
|
||||
const t = new URLSearchParams(location.search).get("t");
|
||||
// your frame(time){…} reads `time`, not Date.now(); RNG uses a fixed seed
|
||||
if (t !== null) { frame(parseFloat(t)); } // render ONE frame, no rAF
|
||||
else { (function loop(now){ frame(now); requestAnimationFrame(loop); })(0); }
|
||||
window.__ready = true;
|
||||
</script>
|
||||
```
|
||||
|
||||
**Verify loop — render → freeze → screenshot → check:** render at a few simulated times (`?t=0`, `?t=1000`, `?t=2000`), screenshot each, and check **fidelity** (ramp reads dark→light correctly, motion evolves) plus **artifacts** (vertical stretch from missing cell-aspect correction, wrong invert on a light bg, clipped grid, FOUC before the monospace font loads — fonts settle the cell metrics, so wait). Any headless tool works:
|
||||
|
||||
```bash
|
||||
npx playwright screenshot --wait-for-timeout=500 "file://$PWD/ascii.html?t=1000" frame-mid.png
|
||||
```
|
||||
|
||||
**Before you finish:**
|
||||
1. Opens standalone — no console errors, CDN (Three.js, if used) loads, monospace font applied.
|
||||
2. `?t=N` renders one deterministic frame (injected time + fixed seed), no live loop.
|
||||
3. Screenshotted at 3 simulated times — matches the brief, no vertical stretch or wrong-invert.
|
||||
4. `prefers-reduced-motion` honored — stop/slow the rAF loop, show a static frame.
|
||||
5. Easing is intentional — frame rate throttled on purpose (12–24fps for retro feel), ramp ordering deliberate.
|
||||
|
||||
## Quick reference
|
||||
|
||||
| Need | Approach |
|
||||
|------|----------|
|
||||
| Simple generative field | `<pre>` + `textContent`, sine/noise → ramp |
|
||||
| Photo fidelity | 70-level Bourke ramp, luminance from sRGB weights |
|
||||
| Per-char color / 60fps | Canvas `fillText` per cell |
|
||||
| Video | `<video>` → offscreen canvas → `getImageData` per frame |
|
||||
| 3D scene | Three.js `AsciiEffect.render(scene, camera)` |
|
||||
| Terminal | ANSI `\x1b[H` home + throttle 12–24fps, hide cursor |
|
||||
| Aspect fix | `rows = cols * imgAspect * 0.5` |
|
||||
|
||||
## Reference files
|
||||
|
||||
- `references/rendering.md` — Full brightness ramp tables (10/70/extended), pixel sampling math and cell aspect correction, `<pre>` vs canvas tradeoffs with code, ANSI terminal frame loop with truecolor, and complete `AsciiEffect` wiring.
|
||||
- `scripts/img-to-ascii.mjs` — Runnable Node script that converts a PNG/JPG file to ASCII text, with `--cols`, `--invert`, and `--ramp` flags.
|
||||
@@ -1,194 +0,0 @@
|
||||
# ASCII Rendering Reference
|
||||
|
||||
Detailed tables, sampling math, and complete renderers for ASCII animation.
|
||||
|
||||
## Brightness ramp tables
|
||||
|
||||
Order is **dark → light**. Index into the ramp with `Math.round(lum * (ramp.length - 1))` where `lum` is 0..1.
|
||||
|
||||
### 10-level (compact, generative)
|
||||
```
|
||||
.:-=+*#%@
|
||||
```
|
||||
Good for low-resolution generative fields and terminals. Distinct steps, low banding artifacts.
|
||||
|
||||
### 70-level Paul Bourke ramp (photo fidelity)
|
||||
```
|
||||
$@B%8&WM#*oahkbdpqwmZO0QLCJUYXzcvunxrjft/\|()1{}[]?-_+~<>i!lI;:,"^`'.
|
||||
```
|
||||
This is ordered **light → dark** (densest first). For luminance mapping, either reverse the string or use `index = Math.round((1 - lum) * (len - 1))`. Best results for grayscale photos; whitespace at the end represents black/empty.
|
||||
|
||||
### 16-level extended (balance)
|
||||
```
|
||||
.'`,^:";~-_+<>i!lI?/\|()1{}[]rcvunxzjftLCJUYXZO0Qoahkbdpqwm*WMB8&%$#@
|
||||
```
|
||||
Truncate or downsample to taste. For UI/loaders a hand-picked 8–12 char ramp usually looks cleaner than a 70-char ramp because the steps are visually distinct.
|
||||
|
||||
### Block / shade characters (Unicode, smoother gradient)
|
||||
```
|
||||
░▒▓█
|
||||
```
|
||||
Or with the 1/8 block fills for vertical bars: `▁▂▃▄▅▆▇█`. Renders as a near-continuous gradient in monospace fonts; great for waveforms, meters, and smooth fades. Requires a font with box-drawing glyphs (most monospace fonts have them).
|
||||
|
||||
## Luminance computation
|
||||
|
||||
Perceptual (sRGB-weighted, recommended):
|
||||
```js
|
||||
const lum = (0.2126 * r + 0.7152 * g + 0.0722 * b) / 255; // 0..1
|
||||
```
|
||||
Fast average (acceptable for stylized output):
|
||||
```js
|
||||
const lum = (r + g + b) / (3 * 255);
|
||||
```
|
||||
Invert for dark-on-light surfaces: `lum = 1 - lum`. Apply gamma to spread midtones: `lum = Math.pow(lum, 0.8)` (lower exponent brightens).
|
||||
|
||||
## Pixel sampling and cell aspect correction
|
||||
|
||||
Monospace cells are about twice as tall as wide. Real cell aspect depends on the font: measure once.
|
||||
|
||||
```js
|
||||
function measureCellAspect(fontFamily = 'monospace', fontPx = 16) {
|
||||
const cv = document.createElement('canvas');
|
||||
const ctx = cv.getContext('2d');
|
||||
ctx.font = `${fontPx}px ${fontFamily}`;
|
||||
const w = ctx.measureText('M').width; // glyph advance width
|
||||
const h = fontPx * 1.0; // with line-height: 1
|
||||
return w / h; // ~0.5 for most fonts
|
||||
}
|
||||
```
|
||||
|
||||
Compute the character grid for a source image, correcting aspect so the picture is not vertically stretched:
|
||||
```js
|
||||
function gridSize(imgW, imgH, cols, cellAspect = 0.5) {
|
||||
const rows = Math.round(cols * (imgH / imgW) * cellAspect);
|
||||
return { cols, rows };
|
||||
}
|
||||
```
|
||||
Draw the source into an offscreen canvas at exactly `cols × rows`, then read all pixels once with `getImageData(0, 0, cols, rows)`. One `getImageData` call per frame is far cheaper than per-pixel reads.
|
||||
|
||||
## `<pre>` vs canvas
|
||||
|
||||
| Aspect | `<pre>` + textContent | Canvas `fillText` |
|
||||
|--------|----------------------|-------------------|
|
||||
| Setup | trivial, one string | per-cell draw loop |
|
||||
| Color | single color (or per-span, slow) | per-char color cheap |
|
||||
| Max size | ~120×60 @ 30fps | thousands of cells @ 60fps |
|
||||
| Selectable text | yes | no |
|
||||
| Best for | generative fields, loaders | video, per-char color, large grids |
|
||||
|
||||
`<pre>` styling that avoids gaps and stretching:
|
||||
```css
|
||||
pre { font-family: ui-monospace, monospace; line-height: 1; letter-spacing: 0;
|
||||
margin: 0; white-space: pre; }
|
||||
```
|
||||
|
||||
Canvas per-char color renderer:
|
||||
```js
|
||||
function drawAsciiCanvas(ctx, chars, colors, cols, rows, cellW, cellH) {
|
||||
ctx.clearRect(0, 0, cols * cellW, rows * cellH);
|
||||
ctx.textBaseline = 'top';
|
||||
ctx.font = `${cellH}px monospace`;
|
||||
for (let y = 0; y < rows; y++) {
|
||||
for (let x = 0; x < cols; x++) {
|
||||
const i = y * cols + x;
|
||||
ctx.fillStyle = colors[i]; // e.g. `rgb(r,g,b)`
|
||||
ctx.fillText(chars[i], x * cellW, y * cellH);
|
||||
}
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
## ANSI terminal frame loop (Node)
|
||||
|
||||
```js
|
||||
const ESC = '\x1b[';
|
||||
const out = process.stdout;
|
||||
|
||||
function start(render, fps = 20) {
|
||||
out.write(ESC + '?25l'); // hide cursor
|
||||
out.write(ESC + '2J'); // clear screen once
|
||||
const interval = 1000 / fps;
|
||||
let start = Date.now();
|
||||
const id = setInterval(() => {
|
||||
const t = Date.now() - start;
|
||||
out.write(ESC + 'H'); // home (cheap, no full clear)
|
||||
out.write(render(t, out.columns || 80, out.rows || 24));
|
||||
}, interval);
|
||||
const stop = () => {
|
||||
clearInterval(id);
|
||||
out.write(ESC + '0m' + ESC + '?25h' + ESC + '2J' + ESC + 'H');
|
||||
process.exit(0);
|
||||
};
|
||||
process.on('SIGINT', stop);
|
||||
return stop;
|
||||
}
|
||||
|
||||
// Truecolor per character: foreground `\x1b[38;2;R;G;Bm`, reset `\x1b[0m`.
|
||||
function colored(ch, r, g, b) {
|
||||
return `${ESC}38;2;${r};${g};${b}m${ch}${ESC}0m`;
|
||||
}
|
||||
|
||||
// Example: plasma using full terminal size
|
||||
start((t, cols, rows) => {
|
||||
const ramp = ' .:-=+*#%@';
|
||||
let s = '';
|
||||
for (let y = 0; y < rows - 1; y++) {
|
||||
for (let x = 0; x < cols; x++) {
|
||||
const v = Math.sin(x * 0.15 + t * 0.001)
|
||||
+ Math.sin(y * 0.25 + t * 0.0015)
|
||||
+ Math.sin((x + y) * 0.1 + t * 0.0008);
|
||||
const lum = (v + 3) / 6;
|
||||
s += ramp[Math.round(lum * (ramp.length - 1))];
|
||||
}
|
||||
s += '\n';
|
||||
}
|
||||
return s;
|
||||
});
|
||||
```
|
||||
Notes: writing `ESC + 'H'` (home) and overwriting is much smoother than clearing the screen every frame, which causes flicker. Avoid printing a trailing newline on the last row or the terminal scrolls. `out.columns`/`out.rows` give the live terminal size; recompute the grid on `process.stdout.on('resize', ...)`.
|
||||
|
||||
## Three.js AsciiEffect — complete wiring
|
||||
|
||||
```js
|
||||
import * as THREE from 'three';
|
||||
import { AsciiEffect } from 'three/addons/effects/AsciiEffect.js';
|
||||
import { OrbitControls } from 'three/addons/controls/OrbitControls.js';
|
||||
|
||||
const renderer = new THREE.WebGLRenderer();
|
||||
renderer.setSize(innerWidth, innerHeight);
|
||||
|
||||
const effect = new AsciiEffect(renderer, ' .:-=+*#%@', { invert: true, resolution: 0.2 });
|
||||
effect.setSize(innerWidth, innerHeight);
|
||||
effect.domElement.style.color = 'white';
|
||||
effect.domElement.style.backgroundColor = 'black';
|
||||
document.body.appendChild(effect.domElement); // append the EFFECT's DOM, not renderer.domElement
|
||||
|
||||
const scene = new THREE.Scene();
|
||||
const camera = new THREE.PerspectiveCamera(70, innerWidth / innerHeight, 1, 1000);
|
||||
camera.position.z = 4;
|
||||
scene.add(new THREE.PointLight(0xffffff, 3).position.set(5, 5, 5));
|
||||
scene.add(new THREE.AmbientLight(0x808080));
|
||||
const mesh = new THREE.Mesh(
|
||||
new THREE.TorusKnotGeometry(1, 0.3, 100, 16),
|
||||
new THREE.MeshStandardMaterial({ flatShading: true })
|
||||
);
|
||||
scene.add(mesh);
|
||||
|
||||
const controls = new OrbitControls(camera, effect.domElement); // attach to effect DOM
|
||||
|
||||
function animate(t) {
|
||||
mesh.rotation.y = t * 0.0005;
|
||||
effect.render(scene, camera); // render through the effect
|
||||
requestAnimationFrame(animate);
|
||||
}
|
||||
requestAnimationFrame(animate);
|
||||
|
||||
addEventListener('resize', () => {
|
||||
camera.aspect = innerWidth / innerHeight; camera.updateProjectionMatrix();
|
||||
effect.setSize(innerWidth, innerHeight);
|
||||
});
|
||||
```
|
||||
Key gotchas: append `effect.domElement` (not the renderer's canvas) and call `effect.render`, not `renderer.render`. `resolution` (default ~0.15) controls character density; lower = fewer, larger characters. Lighting matters — ASCII reads luminance, so use strong directional contrast and `flatShading` for crisp edges.
|
||||
|
||||
---
|
||||
Map brightness to the right glyph ramp and the characters come alive. Built by **[iart.ai](https://iart.ai/?utm_source=github&utm_medium=readme&utm_campaign=web-animation-skills&utm_content=skill_footer&utm_term=ascii-animation)** — the AI motion agent for editable, on-brand motion graphics.
|
||||
@@ -1,64 +0,0 @@
|
||||
#!/usr/bin/env node
|
||||
// img-to-ascii.mjs — Convert a PNG/JPG image to ASCII text.
|
||||
//
|
||||
// Usage:
|
||||
// node img-to-ascii.mjs <image> [--cols 120] [--invert] [--ramp " .:-=+*#%@"]
|
||||
//
|
||||
// Dependency: sharp (npm i sharp). Sharp decodes PNG/JPG/WebP and resizes.
|
||||
//
|
||||
// Notes:
|
||||
// - Applies monospace cell-aspect correction (cells are ~2x taller than wide),
|
||||
// so rows = cols * (imgH/imgW) * 0.5.
|
||||
// - Luminance uses sRGB perceptual weights (0.2126/0.7152/0.0722).
|
||||
|
||||
import sharp from 'sharp';
|
||||
|
||||
function parseArgs(argv) {
|
||||
const args = { cols: 120, invert: false, ramp: ' .:-=+*#%@', file: null };
|
||||
for (let i = 2; i < argv.length; i++) {
|
||||
const a = argv[i];
|
||||
if (a === '--cols') args.cols = parseInt(argv[++i], 10);
|
||||
else if (a === '--invert') args.invert = true;
|
||||
else if (a === '--ramp') args.ramp = argv[++i];
|
||||
else if (!a.startsWith('--')) args.file = a;
|
||||
}
|
||||
return args;
|
||||
}
|
||||
|
||||
async function main() {
|
||||
const { cols, invert, ramp, file } = parseArgs(process.argv);
|
||||
if (!file) {
|
||||
console.error('Usage: node img-to-ascii.mjs <image> [--cols N] [--invert] [--ramp "..."]');
|
||||
process.exit(1);
|
||||
}
|
||||
|
||||
const CELL_ASPECT = 0.5; // monospace width:height
|
||||
const meta = await sharp(file).metadata();
|
||||
const rows = Math.max(1, Math.round(cols * (meta.height / meta.width) * CELL_ASPECT));
|
||||
|
||||
// Resize to the character grid, drop alpha, get raw RGB bytes.
|
||||
const { data } = await sharp(file)
|
||||
.resize(cols, rows, { fit: 'fill' })
|
||||
.removeAlpha()
|
||||
.raw()
|
||||
.toBuffer({ resolveWithObject: true });
|
||||
|
||||
const last = ramp.length - 1;
|
||||
const lines = [];
|
||||
for (let y = 0; y < rows; y++) {
|
||||
let line = '';
|
||||
for (let x = 0; x < cols; x++) {
|
||||
const i = (y * cols + x) * 3;
|
||||
let lum = (0.2126 * data[i] + 0.7152 * data[i + 1] + 0.0722 * data[i + 2]) / 255;
|
||||
if (invert) lum = 1 - lum;
|
||||
line += ramp[Math.round(lum * last)];
|
||||
}
|
||||
lines.push(line);
|
||||
}
|
||||
process.stdout.write(lines.join('\n') + '\n');
|
||||
}
|
||||
|
||||
main().catch((err) => {
|
||||
console.error('Error:', err.message);
|
||||
process.exit(1);
|
||||
});
|
||||
File renamed without changes.
@@ -0,0 +1,229 @@
|
||||
---
|
||||
name: beat-sync-editing
|
||||
description: This skill should be used when the user asks to "cut to the beat", "fix the pacing", "edit this sequence", "sync cuts to music/BPM", "add a match cut / J-cut / L-cut", "build a speed ramp", or "plan a shot sequence / edit timeline". Covers editing rhythm, transitions, retiming, and translating an edit plan to an NLE or a code timeline (Remotion/AE frames).
|
||||
version: 0.1.0
|
||||
---
|
||||
|
||||
# Beat-Sync Editing (Cuts & Rhythm)
|
||||
|
||||
The timeline craft: how clips and beats assemble into a piece that *feels* right. Editing is temporal design — when a cut lands matters as much as what is on screen. This skill turns musical and narrative structure into concrete cut points, transitions, and retimes, expressible in an NLE or as frame numbers in code.
|
||||
|
||||
## When to use
|
||||
|
||||
- Assembling a sequence or cutting footage to a music track.
|
||||
- Pacing drags or feels choppy; transitions feel arbitrary.
|
||||
- Building speed ramps, match cuts, or tension/release structure.
|
||||
- Converting an edit plan into a frame-accurate timeline (Remotion, AE, NLE).
|
||||
|
||||
## Decision tree
|
||||
|
||||
```
|
||||
What's the editing problem?
|
||||
├─ Cuts feel off the music
|
||||
│ └─ get BPM + offset → frames_per_beat = (60/BPM)*fps
|
||||
│ → cut on PHRASES (2/4/8 beats), biggest visual on the drop
|
||||
├─ A cut feels jarring / visible
|
||||
│ └─ cut on action (mid-motion), match direction + velocity
|
||||
│ → still rough? motivate a transition (match / J / L), else hard cut
|
||||
├─ Pacing drags or feels flat
|
||||
│ └─ shape an arc: Establish → Develop → Climax → Resolve
|
||||
│ → shorten avg shot length toward climax, hold after it
|
||||
├─ A hit needs impact
|
||||
│ └─ speed ramp INTO it (slow-mo), snap back; land slowest frame on the beat
|
||||
└─ Need to hand it to code
|
||||
└─ express every cut as a frame number, clip as from/duration,
|
||||
transition as overlap, retime as eased time-remap (Remotion/AE)
|
||||
```
|
||||
|
||||
**Cross-reference — apply the shared frameworks.**
|
||||
|
||||
- **Motion Personality** (`motion-art-direction`) sets cut rhythm: the chosen energy maps straight to phrase length and transition family. Pick one and commit (see the table below).
|
||||
- **Three Pillars** + beat-sync (`animation-principles`): settle *emotional intent* first (hype vs. calm) — it decides whether you cut every bar or hold for four. `animation-principles` defines the BPM→beat relationship; this skill turns it into frame-accurate cut points and the transition/retime craft on top.
|
||||
|
||||
### Motion Personality → cut rhythm
|
||||
|
||||
| Personality | Phrase (cut every) | Transition family | Retime | Reads as |
|
||||
|---|---|---|---|---|
|
||||
| **Playful** | 4 beats, syncopated accents | match cuts, quick whips | light ramps, bouncy | fun, kinetic |
|
||||
| **Premium** | 8–16 beats, long holds | hard cut + occasional dissolve | slow, smooth ramps | elegant, unhurried |
|
||||
| **Corporate** | 8 beats, steady | hard cut, clean | minimal | clean, trustworthy |
|
||||
| **Energetic** | 1–2 beats at climax | hard cut, whips, hard snaps | aggressive ramps on beats | bold, hype |
|
||||
|
||||
## Core workflow
|
||||
|
||||
### 1. Find the grid: BPM → frames
|
||||
|
||||
Cut on the music's rhythmic grid, not on arbitrary timecodes. Convert BPM to frames so cut points are frame-accurate.
|
||||
|
||||
```
|
||||
frames_per_beat = (60 / BPM) * fps
|
||||
```
|
||||
|
||||
At 120 BPM, 30 fps: `(60/120)*30 = 15` frames per beat (500ms/beat) — a cut every 15 frames is on-beat. Cut on *phrases* (every 2/4/8 beats), not every beat, or the edit feels frantic. Land the single biggest visual moment on the musical drop.
|
||||
|
||||
The **eighth-grid**: subdivisions of the beat give finer accent points without going off-grid. At 120 BPM / 30 fps:
|
||||
|
||||
| Subdivision | ms | frames @30fps | Use |
|
||||
|---|---|---|---|
|
||||
| 1 beat (quarter) | 500 | 15 | main cut grid |
|
||||
| ½ beat (eighth) | 250 | 7.5 | accent / quick flash cut |
|
||||
| ¼ beat (sixteenth) | 125 | 3.75 | hits, stutter, transient FX |
|
||||
| 1 bar (4 beats) | 2000 | 60 | phrase / section boundary |
|
||||
|
||||
Snap accents to the eighth-grid; keep structural cuts on the beat or bar.
|
||||
|
||||
```js
|
||||
// Generate on-beat frame numbers (JS / Remotion / AE-friendly)
|
||||
const bpm = 120, fps = 30;
|
||||
const framesPerBeat = (60 / bpm) * fps; // 15
|
||||
const phrase = 4; // cut every 4 beats
|
||||
const cuts = Array.from({length: 16}, (_, i) =>
|
||||
Math.round(i * framesPerBeat * phrase)); // [0,60,120,180,...]
|
||||
```
|
||||
|
||||
### 2. Hide the seam: cut on action / motion
|
||||
|
||||
A cut is invisible when motion carries the eye across it. Cut *during* a movement (a turn, a hand reaching, a whip) so the brain tracks the action through the cut. Match the motion's direction and speed across the cut. For motion-graphics, cut on a transform peak — at the moment a shape is mid-travel, not at rest.
|
||||
|
||||
### 3. Choose transitions with intent
|
||||
|
||||
Default to the **hard cut**. Reach for anything else only when motivated:
|
||||
|
||||
- **Match cut** — outgoing and incoming frames share a shape, position, or motion vector, so the cut reads as a transformation (a circle becomes the moon; a wipe of an arm reveals the next scene). The strongest transition in motion design.
|
||||
- **J-cut** — audio of the *next* shot starts *before* its picture (sound leads). Pulls the viewer forward; great for dialogue and reveals.
|
||||
- **L-cut** — audio of the *current* shot continues *under* the next picture (sound trails). Smooths scene changes.
|
||||
- **Whip / motion blur transition** — fast pan blends two shots; needs matched blur direction.
|
||||
- **Luma/wipe/dissolve** — signals time passing or a softer mood; overuse reads as amateur.
|
||||
|
||||
Cut-type quick table:
|
||||
|
||||
| Cut type | What aligns | Signals | Typical offset | Reach for it when |
|
||||
|---|---|---|---|---|
|
||||
| Hard cut | nothing — instant | neutral, default | 0 | 90% of cuts |
|
||||
| Match cut | shared shape / position / motion vector | transformation | 0 (1–2f tolerance) | two shots rhyme visually |
|
||||
| J-cut | audio of B leads its picture | pulls viewer forward | audio 4–12f early | dialogue, reveals |
|
||||
| L-cut | audio of A trails under B | smooths the change | audio 12–24f late | scene changes, ambient |
|
||||
| Whip / motion blur | matched blur direction across pan | energy, "swoosh" | ~6–10f blend | hype, scene jumps |
|
||||
| Speed ramp | retime, not a cut | impact / emphasis | lands on beat | a hit needs to land |
|
||||
|
||||
### 4. Retime: speed ramps
|
||||
|
||||
Speed ramps (gradual time-warp) add impact: ramp *into* a hit with slow-motion, then snap back to speed. Keep motion blur consistent through the ramp or the slow section looks strobed.
|
||||
|
||||
```
|
||||
Speed ramp on an impact (frames, 30fps):
|
||||
0–20 100% speed (run-up)
|
||||
20–28 ease down to 25% (anticipation, slow-mo on the hit)
|
||||
28 IMPACT lands on the beat
|
||||
28–40 ease back to 100% (release)
|
||||
```
|
||||
|
||||
In an NLE use time-remap keyframes with smooth interpolation and enable frame-blending/optical-flow for clean slow-mo. In Remotion/AE, drive a `timeRemap`/`valueAtTime` curve with eased interpolation and keep a consistent shutter/motion-blur setting.
|
||||
|
||||
### 5. Shape the arc: sequence pacing
|
||||
|
||||
A piece needs a shape, not one constant intensity:
|
||||
|
||||
```
|
||||
Establish → Develop → Climax → Resolve
|
||||
longer holds shortening cuts fastest + the drop release/breathe
|
||||
```
|
||||
|
||||
Vary shot length deliberately: fast cuts build energy, longer holds let key moments land. Build toward the climax by shortening average shot length, then give a beat of rest after it. The classic mistake is uniform pacing — it reads as flat regardless of content.
|
||||
|
||||
Pacing arc — tension → release (energy is the *derivative* of cut frequency):
|
||||
|
||||
| Phase | Cut every | Avg shot length | Tension | Note |
|
||||
|---|---|---|---|---|
|
||||
| Establish | 8–16 beats | longest | low | set place/mood, let it breathe |
|
||||
| Develop | 8 → 4 beats | shortening | rising | accelerate cuts to build |
|
||||
| Climax | 1–2 beats | shortest | peak | the drop; biggest visual + speed ramp |
|
||||
| Resolve | one long hold | longest | release | logo/CTA breathes after the peak |
|
||||
|
||||
## Quick reference
|
||||
|
||||
| Goal | Move |
|
||||
|---|---|
|
||||
| On-beat cut | `(60/BPM)*fps` frames per beat; cut on phrases |
|
||||
| Land the drop | biggest visual on the musical drop |
|
||||
| Invisible cut | cut on action / matched motion |
|
||||
| Transform feel | match cut (shared shape/motion) |
|
||||
| Pull forward | J-cut (audio leads) |
|
||||
| Smooth scene change | L-cut (audio trails) |
|
||||
| Impact | speed ramp into the hit, snap out |
|
||||
| Build energy | shorten average shot length |
|
||||
| Let it breathe | hold after the climax |
|
||||
|
||||
## Worked examples
|
||||
|
||||
### GOOD — 30s energetic product spot, 128 BPM, 30 fps
|
||||
|
||||
> **Brief**: hype sneaker drop, Energetic personality, drop at beat 32.
|
||||
>
|
||||
> - **Grid**: 14.06 f/beat. Drop = beat 32 ≈ frame 450 (rounded cumulatively to avoid drift).
|
||||
> - **Arc**: Establish 0–120 (two 2s holds). Develop 120–450 (cuts shortening 8→4→2 beats, rising energy — matches Energetic). Climax at 450 (the drop). Resolve 700–900 (one long CTA hold).
|
||||
> - **Cuts**: structural cuts on the bar; two accent flash-cuts snapped to the eighth-grid in Develop.
|
||||
> - **Craft**: f112 is a match cut (shared circular logo → wheel). The drop at 450 carries the biggest visual *and* a speed ramp 100%→25%→100% landing the slowest frame on the downbeat. CTA enters under an L-cut (audio trails ~18f).
|
||||
> - **To code**: each cut a frame number, each clip `<Sequence from/durationInFrames>`, ramp = eased time-remap, beats verified `frame/fps` against detected beat seconds.
|
||||
>
|
||||
> Why it works: phrase-based grid, an arc, one big moment on the drop, motivated transitions, frame-accurate and portable.
|
||||
|
||||
### ANTI-PATTERN — "cut on every beat with a dissolve each time"
|
||||
|
||||
> - A hard cut on all 32 beats → relentless, no focal moment, viewer fatigues by beat 8.
|
||||
> - A 12-frame crossfade on *every* cut to "smooth it" → mushy, amateur, and now nothing is on the beat because the dissolve midpoint drifts off-grid.
|
||||
> - Uniform 15-frame shots start to finish → flat; no establish, no climax, the drop lands on nothing.
|
||||
> - BPM math done from frame 0 ignoring the track's offset → every cut sits a few frames early, feels "almost right" but wrong.
|
||||
>
|
||||
> Fix: cut on 4/8-beat phrases, hard cut by default, build an arc, anchor the grid to beat-1 offset, and put the one biggest visual on the drop.
|
||||
|
||||
## Common mistakes
|
||||
|
||||
| Symptom | Why | Fix |
|
||||
|---|---|---|
|
||||
| Edit feels frantic / busy | cutting on every beat | cut on 2/4/8-beat phrases; accent on the eighth-grid sparingly |
|
||||
| Cuts feel "almost on beat" | grid started at 0:00, ignored track offset | capture beat-1 offset; anchor cumulative frame math to it |
|
||||
| Drift over a long edit | rounding frames_per_beat per step | round each *cumulative* beat, not per-step |
|
||||
| Cut feels jarring | placed at rest, between motions | cut on action / mid-motion; match direction + velocity |
|
||||
| Slow-mo strobes | sub-100% speed without interpolated frames | enable optical-flow / frame-blending; consistent shutter |
|
||||
| Whole piece feels flat | uniform pacing | shape Establish→Develop→Climax→Resolve; shorten toward the drop |
|
||||
| Transitions look amateur | dissolves/wipes used as a crutch | default to hard cut; motivate match/J/L; fix timing first |
|
||||
| Nothing lands | no single climax | put the biggest visual on the drop; hold after it |
|
||||
|
||||
## Deliverable — an edit-timing plan
|
||||
|
||||
A good plan is renderer-agnostic and hands off to an NLE or a code timeline (`remotion-video`, `after-effects`):
|
||||
|
||||
- **Track spec**: BPM, fps, beat-1 offset, drop frame(s), frames_per_beat.
|
||||
- **Arc**: the four phases with frame ranges and target average shot length per phase.
|
||||
- **Cut list**: every cut as an absolute **frame number** (from the BPM math), the clip at that cut, and the cut type.
|
||||
- **Transitions**: type (hard/match/J/L/whip), and for J/L the audio offset in frames.
|
||||
- **Retimes**: each speed ramp as eased time-remap keyframes (from→to %, frames, optical-flow on).
|
||||
- **Beat markers**: the on-beat/eighth-grid frame array for verification.
|
||||
- **Cross-refs**: the Motion Personality that set the rhythm.
|
||||
|
||||
> For Remotion/AE this plan IS the frame timing: cuts → `from`/`durationInFrames` (or layer in/out), ramps → eased `interpolate`/time-remap, J/L → offset `<Audio from>` / audio layer. See `references/editing-techniques.md` for the NLE↔code mapping table.
|
||||
|
||||
### Before you finish — checklist
|
||||
|
||||
- [ ] BPM + fps + beat-1 offset captured; frames_per_beat computed and cumulatively rounded.
|
||||
- [ ] Cuts on phrases (2/4/8 beats), not every beat; accents on the eighth-grid only.
|
||||
- [ ] The single biggest visual lands on the drop.
|
||||
- [ ] An arc exists (Establish→Develop→Climax→Resolve); avg shot length shortens toward the climax, then a hold.
|
||||
- [ ] Hard cut is the default; every other transition is motivated; J/L audio offsets specified in frames.
|
||||
- [ ] Speed ramps land the slowest frame on the beat; optical-flow/frame-blending enabled.
|
||||
- [ ] Cut rhythm matches the chosen Motion Personality.
|
||||
- [ ] Every cut, transition, and retime expressed as a frame number / from-duration so it ports to Remotion/AE/NLE.
|
||||
- [ ] Audio sync verified: `frame/fps` against detected beat seconds.
|
||||
|
||||
## Gotchas
|
||||
|
||||
- Cutting on *every* beat is busy; cut on 2/4/8-beat phrases and accent sparingly.
|
||||
- Speed ramps without consistent motion blur look strobed; enable optical-flow/frame-blending for slow-mo.
|
||||
- Crossfades/dissolves are not a fix for a bad cut — fix the timing first.
|
||||
- Audio sync drift: in code timelines verify `frame/fps` against detected beat seconds; in NLEs lock audio to a frame-accurate guide track.
|
||||
- One pacing throughout = flat. Always shape an arc.
|
||||
|
||||
## Reference files
|
||||
|
||||
- `references/editing-techniques.md` — BPM→frame math with phrase tables, cut-on-action breakdowns, building a match cut step by step, J-cut/L-cut audio-lead/trail diagrams with frame offsets, full speed-ramp recipe with motion-blur/optical-flow settings, sequence-arc templates with shot-length curves, and mapping an edit plan between an NLE timeline and a code timeline (Remotion `<Sequence>` / AE time-remap).
|
||||
@@ -0,0 +1,137 @@
|
||||
# Editing Techniques — Detailed Cookbook
|
||||
|
||||
Concrete recipes for rhythm, transitions, and retiming, with the math to make cuts frame-accurate.
|
||||
|
||||
## BPM → frame math
|
||||
|
||||
```
|
||||
frames_per_beat = (60 / BPM) * fps
|
||||
seconds_per_beat = 60 / BPM
|
||||
```
|
||||
|
||||
Reference (frames per beat):
|
||||
|
||||
| BPM | 24 fps | 25 fps | 30 fps | 60 fps |
|
||||
|----|----|----|----|----|
|
||||
| 90 | 16.0 | 16.7 | 20.0 | 40.0 |
|
||||
| 100 | 14.4 | 15.0 | 18.0 | 36.0 |
|
||||
| 120 | 12.0 | 12.5 | 15.0 | 30.0 |
|
||||
| 128 | 11.25| 11.7 | 14.06| 28.13|
|
||||
| 140 | 10.3 | 10.7 | 12.86| 25.7 |
|
||||
|
||||
When `frames_per_beat` is fractional (e.g. 128 BPM at 30 fps = 14.06), round each *cumulative* beat to avoid accumulating drift:
|
||||
|
||||
```js
|
||||
const cut = (i) => Math.round(i * (60 / bpm) * fps); // round at the end, not per-step
|
||||
```
|
||||
|
||||
Cut on phrases, not beats:
|
||||
|
||||
| Energy | Cut every |
|
||||
|---|---|
|
||||
| Frantic / climax | 1–2 beats |
|
||||
| Energetic | 4 beats (1 bar in 4/4) |
|
||||
| Moderate | 8 beats (2 bars) |
|
||||
| Calm / establishing | 16 beats (4 bars) |
|
||||
|
||||
Detect BPM offline (aubio, `web-audio-beat-detector`, or tap-tempo) and also capture the *offset* of beat 1 — the grid rarely starts at 0:00.
|
||||
|
||||
## Cut on action / cut on motion
|
||||
|
||||
The eye tracks moving subjects; a cut placed mid-motion is masked by that movement.
|
||||
|
||||
- Identify a continuous action spanning two shots (door opening, head turn, object thrown).
|
||||
- Place the cut roughly one-third into the action, and continue the *same* action and direction in the next shot.
|
||||
- Match screen direction (subject moving left exits left, enters from right) and velocity.
|
||||
- In motion graphics: cut while a shape is mid-travel (transform velocity high), not when it has settled — the motion blur and momentum hide the splice.
|
||||
|
||||
## Match cut, step by step
|
||||
|
||||
A match cut equates two shots via a shared visual so the cut reads as a transformation.
|
||||
|
||||
1. Find or design a shape/position/motion shared by the end of shot A and the start of shot B (a round clock → a round wheel; an arm wiping frame → next scene revealed).
|
||||
2. Align them in screen space: same size, same position, same orientation at the cut frame.
|
||||
3. Match motion vector and speed across the cut so momentum carries through.
|
||||
4. Cut on the exact frame where the two forms register; a 1–2 frame mismatch breaks the illusion.
|
||||
5. Optionally add a 1–3 frame motion-blur bridge to fuse them.
|
||||
|
||||
Common forms: graphic match (shape), motion match (direction/velocity), audio match (a sound bridges the cut), and the "invisible wipe" where a foreground object wipes the frame and the next shot is revealed behind it.
|
||||
|
||||
## J-cut and L-cut
|
||||
|
||||
Audio and picture do not have to cut at the same frame.
|
||||
|
||||
```
|
||||
J-CUT (audio of B leads its picture — pulls forward)
|
||||
Picture: AAAAAAAA | BBBBBBBB
|
||||
Audio: AAAAA BBBBBBBBBBBBB
|
||||
^ B's audio starts ~6–12 frames early
|
||||
|
||||
L-CUT (audio of A trails under B's picture — smooths)
|
||||
Picture: AAAAAAAA | BBBBBBBB
|
||||
Audio: AAAAAAAAAAAA BBBBBB
|
||||
^ A's audio continues ~6–18 frames past the picture cut
|
||||
```
|
||||
|
||||
Typical offsets: dialogue J-cuts 4–12 frames; ambient L-cuts 12–24 frames. In an NLE, unlink audio/video and trim only the audio edge. In a code timeline, place the `<Audio>` for shot B with a `from` earlier than B's picture sequence.
|
||||
|
||||
## Speed ramp recipe (with motion blur)
|
||||
|
||||
```
|
||||
Impact ramp, 30 fps, drop on frame 28:
|
||||
Frame Speed Note
|
||||
0–20 100% run-up, normal motion blur
|
||||
20–28 100%→25% ease-OUT deceleration into the hit
|
||||
28 25% IMPACT, lands on the downbeat
|
||||
28–34 25%→100% ease-IN re-acceleration
|
||||
34+ 100% release
|
||||
```
|
||||
|
||||
Settings:
|
||||
- Use smooth (Bezier) interpolation on time-remap keyframes; linear ramps look mechanical.
|
||||
- Enable **optical flow** (or frame-blending) for sub-100% speeds so slow-mo isn't strobed; optical flow generates intermediate frames.
|
||||
- Keep motion-blur shutter consistent across the ramp — if the source has motion blur, the slow section keeps it; if synthetic, hold a constant shutter angle (e.g. 180°).
|
||||
- Land the slowest frame *on the beat*; the ramp is felt, the impact is heard.
|
||||
|
||||
In AE: enable time remapping, keyframe the source time, ease the keyframes, set frame blending to Pixel Motion. In Remotion: drive a remapped source time via eased `interpolate` and keep effects deterministic.
|
||||
|
||||
## Sequence arc templates
|
||||
|
||||
```
|
||||
30s social spot (≈ 900 frames @30fps):
|
||||
Establish 0–120 2 shots, ~2s each (longer holds)
|
||||
Develop 120–540 shots shortening 1.5s → 0.8s, rising energy
|
||||
Climax 540–720 fastest cuts 0.3–0.5s, the drop at ~600
|
||||
Resolve 720–900 one long hold, logo/CTA breathes
|
||||
```
|
||||
|
||||
Plot average shot length as a curve: high at the start, descending to the climax, then a single long shot to release. Energy is the *derivative* of cut frequency — accelerate cuts to build, decelerate to land.
|
||||
|
||||
## NLE timeline vs code timeline
|
||||
|
||||
| Concept | NLE | Remotion | After Effects |
|
||||
|---|---|---|---|
|
||||
| Clip placement | drag to track at TC | `<Sequence from durationInFrames>` | layer in/out points |
|
||||
| Back-to-back shots | adjacent clips | `<Series>` | trimmed layers |
|
||||
| Crossfade | overlap + dissolve | overlap `Series` + opacity interp | opacity keyframes / overlap |
|
||||
| Speed ramp | time-remap keyframes | eased source-time `interpolate` | time remap + frame blending |
|
||||
| J/L cut | unlink + trim audio | `<Audio from>` ≠ picture seq | offset audio layer |
|
||||
| Beat marker | timeline markers | beat array `frame/fps` | comp markers / expression |
|
||||
|
||||
To port an edit plan: express each cut as a frame number (from the BPM math), each clip as `from`/`duration`, each transition as an overlap, and each retime as an eased time-remap. The plan is renderer-agnostic; only the placement syntax differs.
|
||||
|
||||
## Example edit plan (portable)
|
||||
|
||||
```
|
||||
Track: 128 BPM, 30fps → 14.06 f/beat, drop at beat 32 (frame 450)
|
||||
Cut on 4-beat phrases (≈56 frames):
|
||||
f0 ShotA establish, hold
|
||||
f56 ShotB cut on action (subject turns)
|
||||
f112 ShotC match cut from B (shared circle)
|
||||
f168 ... cuts shorten toward climax
|
||||
f450 DROP biggest visual; speed ramp 100→25→100 around f450
|
||||
f700 CTA long hold, L-cut audio trails in
|
||||
```
|
||||
|
||||
---
|
||||
Cut on the beat and ramp with purpose and the edit moves with the music. Built by **[iart.ai](https://iart.ai/?utm_source=github&utm_medium=readme&utm_campaign=motion-design-skills&utm_content=skill_footer&utm_term=beat-sync-editing)** — the AI motion agent for editable, on-brand motion graphics.
|
||||
File renamed without changes.
@@ -0,0 +1,175 @@
|
||||
---
|
||||
name: color-motion
|
||||
description: This skill should be used when the user asks to "build a color palette for a motion piece", "make a gradient background", "animate a color transition", "interpolate colors smoothly", "fix muddy/gray gradients", "convert colors to OKLCH", "color-grade a video for mood", "fix washed-out After Effects renders", "gamma shift", "Rec.709 vs sRGB", "colors shifted after rendering", or "match preview to final video". Covers palette construction, gradients, perceptual interpolation (OKLCH/Lab), grading order, and video/render color management.
|
||||
version: 0.1.0
|
||||
---
|
||||
|
||||
# Color in Motion
|
||||
|
||||
Choose, pair, and animate color for motion design: building restrained palettes, constructing gradients that read as premium, interpolating colors in perceptually-uniform spaces, and grading a piece for mood and consistency. Produces palettes with exact OKLCH/hex values, gradient CSS/code, and transition parameters.
|
||||
|
||||
## When to use
|
||||
|
||||
- Picking or pairing a palette for a motion or video piece.
|
||||
- Building gradient backgrounds (mesh, noise, animated drift).
|
||||
- Animating color transitions (button states, theme switch, loaders).
|
||||
- Grading a video for mood, or fixing dull/gray gradient interpolation.
|
||||
- Fixing washed-out, gamma-shifted, or platform-inconsistent After Effects renders, and choosing correct per-platform export/color tags.
|
||||
|
||||
## Core techniques
|
||||
|
||||
### 1. Build a restrained palette
|
||||
|
||||
Limit hues. A strong motion palette is **1 primary + 1 accent + 2-3 neutrals**. Derive contrast and depth from lightness and chroma, not from adding more hues. Extra hues fight for attention and read as amateur.
|
||||
|
||||
In dark scenes, make the accent pop with **low-to-moderate chroma and high lightness** rather than maximum saturation — a blown-out saturated accent vibrates and looks cheap on dark backgrounds.
|
||||
|
||||
Use OKLCH to reason about color: `oklch(L C H)` where L is perceptual lightness (0-1), C is chroma (0 ≈ 0.37 max), H is hue angle (0-360). Holding L and C constant while rotating H gives hues of genuinely equal visual weight — impossible to do reliably in HSL.
|
||||
|
||||
```
|
||||
Primary: oklch(0.62 0.19 264) /* confident blue */
|
||||
Accent: oklch(0.78 0.17 50) /* warm amber, lighter so it pops */
|
||||
Neutral-0: oklch(0.97 0.005 264) /* near-white, faint hue tint */
|
||||
Neutral-1: oklch(0.55 0.01 264)
|
||||
Neutral-2: oklch(0.18 0.015 264) /* near-black, same hue family */
|
||||
```
|
||||
|
||||
Tinting neutrals slightly toward the primary hue (tiny chroma) unifies the frame; pure gray neutrals next to colored elements look disconnected.
|
||||
|
||||
### 2. Interpolate in OKLCH or Lab — never raw sRGB
|
||||
|
||||
Linearly interpolating two colors in sRGB passes through a desaturated, often gray or muddy midpoint (blue->yellow goes through gray; blue->red through muddy purple). Perceptual spaces (OKLCH, OKLab, CIE Lab) keep midpoints vivid and lightness even.
|
||||
|
||||
CSS gradients support this natively:
|
||||
|
||||
```css
|
||||
/* Vivid, even midpoint */
|
||||
background: linear-gradient(in oklch, #2b6cff, #ffb02e);
|
||||
|
||||
/* Control hue path around the wheel for two-stop gradients */
|
||||
background: linear-gradient(in oklch longer hue, #2b6cff, #ffb02e);
|
||||
background: conic-gradient(in oklch, red, blue, red);
|
||||
```
|
||||
|
||||
For animated transitions interpolate with a library (see references) and emit per-frame colors, or for two-color CSS transitions register a typed custom property so the browser interpolates in the chosen space.
|
||||
|
||||
### 3. Gradients that read as premium
|
||||
|
||||
- **Mesh / multi-radial**: stack several `radial-gradient`s at different positions over a base color. Soft, organic, expensive-looking.
|
||||
- **Add grain**: a faint noise overlay (SVG `feTurbulence` or a tiled PNG at ~3-5% opacity) kills banding and adds texture.
|
||||
- **Animate slowly**: drift gradient positions over 8-20s with `ease-in-out alternate`. Slow is premium; fast gradient motion looks like a screensaver.
|
||||
|
||||
```css
|
||||
.mesh {
|
||||
background-color: #0b0f1a;
|
||||
background-image:
|
||||
radial-gradient(at 20% 25%, oklch(0.62 0.19 264 / 0.7), transparent 50%),
|
||||
radial-gradient(at 80% 30%, oklch(0.70 0.16 320 / 0.6), transparent 55%),
|
||||
radial-gradient(at 50% 85%, oklch(0.78 0.17 50 / 0.5), transparent 50%);
|
||||
animation: drift 16s ease-in-out infinite alternate;
|
||||
}
|
||||
@keyframes drift {
|
||||
to { background-position: 8% -6%, -8% 6%, 4% 8%; }
|
||||
}
|
||||
```
|
||||
|
||||
### 4. Color transition animation
|
||||
|
||||
Inline timing essentials so this skill stands alone: enter/highlight with ease-out (`cubic-bezier(0.16, 1, 0.3, 1)`), state changes 150-300ms, theme/full-screen washes 400-800ms. Use `linear` only for continuous loops.
|
||||
|
||||
```css
|
||||
@property --c { syntax: "<color>"; initial-value: #2b6cff; inherits: false; }
|
||||
.btn { background: var(--c); transition: --c 200ms cubic-bezier(0.16,1,0.3,1); }
|
||||
.btn:hover { --c: #ffb02e; }
|
||||
```
|
||||
|
||||
`@property` registration is what makes the color actually interpolate (unregistered custom properties jump instantly).
|
||||
|
||||
### 5. Grade for mood — correct order
|
||||
|
||||
Apply grading operations in this order; reordering changes the result:
|
||||
|
||||
1. **Exposure / white balance** — fix overall brightness and neutralize/intentionally set the cast first.
|
||||
2. **Contrast** — set black and white points; expand or compress the tonal range.
|
||||
3. **Midtones / saturation** — adjust overall saturation and midtone color.
|
||||
4. **Split-tone** — tint shadows and highlights separately. The classic cinematic look is **teal shadows + orange highlights** (complementary, flatters skin). Keep it subtle.
|
||||
5. **Unify** — a final overall tint/LUT and a subtle vignette to bind the frame.
|
||||
|
||||
In code, grade by chaining CSS filters or a fragment shader; for video, an actual LUT or grading panel. Always grade the whole piece consistently so shots cut together.
|
||||
|
||||
### 6. Video / render color management
|
||||
|
||||
When a render looks correct in the After Effects comp viewer but washed-out, too bright, milky, or gamma-shifted in QuickTime, a browser, or across macOS/Windows, the cause is a gamma/transfer mismatch across four stages — AE working space, the render's embedded tag, the player's interpretation, and the display/OS gamma — not the artwork.
|
||||
|
||||
Core rules:
|
||||
|
||||
- **Set an explicit working space.** File > Project Settings > Color tab: Working Space = **Rec.709 Gamma 2.4** for SDR video (or **sRGB** for UI/stills); "None" disables color management and the viewer lies about the final look. Set Depth to **16 bpc** for grades/gradients to avoid banding.
|
||||
- **Rec.709 vs sRGB.** They share primaries but differ in transfer (sRGB ~2.2 piecewise vs Rec.709 display 2.4 / BT.1886). Using the wrong one shifts midtone brightness — Rec.709 for video, sRGB for screenshots/PNG/UI.
|
||||
- **Embed a color tag on export.** The shift across macOS/Windows/players comes from untagged files; each player guesses its own default. Tag Rec.709 (or sRGB) explicitly via Render Queue > **Output Module > Color Management** (do not leave "Preserve RGB" when a shift occurs).
|
||||
- **The QuickTime gamma bug.** QuickTime/AVFoundation apply an extra ~1.96 gamma, so a file can look fine in QuickTime but dark/contrasty in Chrome. **Never grade or approve to QuickTime** — Chrome, Premiere, or Resolve is the correct reference for web delivery.
|
||||
- **Match preview to final.** Toggle "Use Display Color Management" in the comp viewer while reviewing, and verify the export numerically: place a 50% grey (RGB 128) patch, render, re-sample — a value that rises (128 → 150+) confirms a washed-out gamma shift. Confirm the embedded tag with `ffprobe` (`color_primaries`/`color_transfer`/`color_space` = bt709).
|
||||
|
||||
Per-platform export at a glance: **ProRes 422 HQ/4444** tagged Rec.709 for editing masters; **H.264 (MP4)** tagged Rec.709 for web/`<video>`/social (verify in Chrome); ProRes 4444 + alpha → PNG (sRGB) for transparency; ProRes 4444 / HEVC 10-bit Rec.2020 PQ/HLG for HDR (needs 32 bpc float).
|
||||
|
||||
See `references/color-management.md` for the full diagnosis decision tree, exact menu paths, per-platform export table, the QuickTime workarounds, per-OS/player gamma values, the numeric test-patch method, `ffprobe`/`ffmpeg` tag commands, limited-vs-full-range pitfalls, and the pre-export checklist.
|
||||
|
||||
## Deliver & verify (standalone HTML)
|
||||
|
||||
> **Packaged helper** (`scripts/`): `scripts/seek-shot.sh anim.html 0 1.5 3` freezes the `?t=N` harness and screenshots each moment; `scripts/contact-sheet.sh sheet.png frame-*.png` tiles them for one-glance review. See `scripts/README.md`.
|
||||
|
||||
For a web palette/gradient/color-transition deliverable, ship **one `.html` file that opens directly in a browser** — no build step. CSS handles the color work; the file is self-contained.
|
||||
|
||||
**Output contract:**
|
||||
- One `.html` file: your markup + the gradient/transition in inline `<style>` (CDN only if a JS interpolation lib is needed).
|
||||
- One animation driver — a CSS `@keyframes` drift or a single `@property` transition; nothing competing.
|
||||
- Include the freeze harness below so any moment can be screenshotted deterministically.
|
||||
|
||||
**Freeze harness — pin a CSS-animation frame for screenshots.** `?t=N` sets a negative `animation-delay` and pauses, so the gradient/transition lands on the exact frame at `N` seconds.
|
||||
|
||||
```html
|
||||
<script>
|
||||
const t = new URLSearchParams(location.search).get("t");
|
||||
if (t !== null) {
|
||||
document.querySelectorAll(".bg, .btn").forEach(el => { // animated elements
|
||||
el.style.animationDelay = (-parseFloat(t)) + "s";
|
||||
el.style.animationPlayState = "paused";
|
||||
});
|
||||
}
|
||||
window.__ready = true; // ready signal for headless wait
|
||||
</script>
|
||||
```
|
||||
|
||||
**Verify loop — render → freeze → screenshot → check:**
|
||||
1. Open the file frozen at start / mid / end: `…/color.html?t=0`, `?t=<period/2>`, `?t=<period>`.
|
||||
2. Screenshot each frozen frame.
|
||||
3. Check **fidelity** (matches the palette/brief) and **color artifacts** — at each frozen frame confirm the gradient/transition has **no banding and no muddy or gray midpoint** (the OKLCH/Lab path stays vivid). Add grain if banding appears.
|
||||
4. **Iterate:** if banding or a muddy/gray midpoint shows up, adjust the OKLCH/Lab chroma & lightness (or add grain), re-render the **same** `?t=N`, and re-screenshot to confirm the fix — loop until every frozen frame is clean.
|
||||
|
||||
```bash
|
||||
npx playwright screenshot --wait-for-timeout=500 "file://$PWD/color.html?t=8" frame-mid.png
|
||||
```
|
||||
|
||||
**Before you finish:**
|
||||
1. Opens standalone in a browser — no console errors, no missing CDN.
|
||||
2. One color driver; `?t=N` freezes the exact frame correctly.
|
||||
3. Screenshotted at start / mid / end — no banding, no muddy/gray midpoints, lightness even.
|
||||
4. `prefers-reduced-motion` honored (drift paused on a static, readable frame).
|
||||
5. Interpolation is in OKLCH/Lab (gradients/`@property`), never raw sRGB.
|
||||
|
||||
## Quick reference
|
||||
|
||||
| Need | Do |
|
||||
|---|---|
|
||||
| Palette size | 1 primary + 1 accent + 2-3 neutrals |
|
||||
| Equal-weight hues | hold L,C in OKLCH, vary H |
|
||||
| Vivid gradient | `linear-gradient(in oklch, ...)` |
|
||||
| Smooth color anim | interpolate in OKLCH/Lab, register via `@property` |
|
||||
| Premium bg | stacked radials + grain + 8-20s slow drift |
|
||||
| Cinematic grade | teal shadows / orange highlights, subtle |
|
||||
| Fix washed-out AE render | tag Rec.709 in Output Module > Color Management; verify in Chrome |
|
||||
| Avoid | raw-sRGB interpolation (muddy midpoints); grading to QuickTime |
|
||||
|
||||
## Reference files
|
||||
|
||||
- `references/palettes-and-interpolation.md` — palette construction rules with OKLCH values and named recipes, gradient cookbook (mesh, conic, grain), culori and d3-interpolate code for perceptual interpolation and scales, and the full grading-order checklist with filter/shader examples.
|
||||
- `references/color-management.md` — full video/render color management: diagnosis decision tree, AE project/output color settings with exact menu paths, per-platform export table, QuickTime gamma-bug workarounds, per-OS/player gamma values, the numeric test-patch method, `ffprobe`/`ffmpeg` tag verification, limited-vs-full-range pitfalls, and the pre-export checklist.
|
||||
@@ -0,0 +1,165 @@
|
||||
# Video / render color management (After Effects)
|
||||
|
||||
How to diagnose and prevent the most common After Effects color complaint: a render that looks correct inside the AE composition viewer but appears washed-out, too bright, milky, or gamma-shifted when played in QuickTime Player, uploaded to a browser, or moved between macOS and Windows. The root cause is almost always a mismatch in how gamma / transfer functions are interpreted across AE, the codec metadata, the OS player, and the display pipeline — not a problem with the artwork.
|
||||
|
||||
## Mental model: where shifts come from
|
||||
|
||||
A pixel value travels through four stages, each of which can apply or assume a gamma. A shift is a mismatch between two of them:
|
||||
|
||||
1. **AE project working space** — the math AE uses internally (linear vs a tagged display space). Set in File > Project Settings > Color tab.
|
||||
2. **The render's embedded tag** — what transfer/primaries metadata the codec writes (or omits) into the file.
|
||||
3. **The player's interpretation** — QuickTime, Chrome, VLC, and Windows Media each guess differently when the tag is missing or when they apply ColorSync.
|
||||
4. **The display + OS gamma** — macOS historically assumed ~1.8, now ~2.2/2.4-ish via ColorSync; the long-standing "QuickTime gamma bug" comes from QuickTime/AVFoundation applying an extra gamma curve (~1.96) that Chrome and most editors do not.
|
||||
|
||||
Key fact: most web video is **Rec.709**, whose camera/encode side is roughly gamma 2.2-ish but whose *standard display* gamma is **2.4** (BT.1886). macOS QuickTime effectively renders nearer **1.96**, which is why a file can look fine in QuickTime but slightly dark/contrasty in a browser, or vice-versa. The fix is never "eyeball it in QuickTime" — QuickTime is the least trustworthy reference.
|
||||
|
||||
## Decision tree: which problem is this?
|
||||
|
||||
```
|
||||
Render looks DIFFERENT from comp preview?
|
||||
├─ Looks washed-out / milky / brighter, low contrast
|
||||
│ └─ Almost always: untagged or mistagged H.264/ProRes +
|
||||
│ player applying its own gamma (QuickTime gamma bug).
|
||||
│ → Use ProRes for masters; tag Rec.709; verify in
|
||||
│ Chrome, NOT QuickTime.
|
||||
├─ Looks fine in QuickTime, WRONG (dark/contrasty) in Chrome
|
||||
│ └─ QuickTime is applying ~1.96 gamma; Chrome honors the
|
||||
│ 2.4/sRGB pipeline. The browser is the correct reference
|
||||
│ for web delivery.
|
||||
├─ Looks fine on macOS, wrong on Windows (or reverse)
|
||||
│ └─ Missing color tag → each OS assumes a default. Embed an
|
||||
│ explicit Rec.709 (or sRGB) tag on export.
|
||||
└─ Banding / posterization in gradients
|
||||
└─ 8-bit project on heavy grades. Set Project > Depth to
|
||||
16 bpc and/or enable Linearize Working Space.
|
||||
```
|
||||
|
||||
## Project Color Settings (exact menu paths)
|
||||
|
||||
Open **File > Project Settings… > Color** tab.
|
||||
|
||||
- **Depth**: set to **16 bits per channel** for grades/gradients (8 bpc is fine for simple cuts; 32 bpc float only for HDR/heavy linear comps).
|
||||
- **Working Space**: For standard web/SDR delivery choose **Rec.709 Gamma 2.4** (or **sRGB IEC61966-2.1** if the deliverable is screenshots/UI). Setting any working space (not "None") turns AE color management ON, so the viewer now shows display-referred color consistently.
|
||||
- **Linearize Working Space** / **Blend Colors Using 1.0 Gamma**: enable when doing glows, blurs, and additive composites so blending math is physically correct. This changes the look of feathered edges and screen blends — enable it early, not at the end.
|
||||
- **Compensate for Scene-referred Profiles**: leave default unless mixing log/cineon footage.
|
||||
|
||||
To preview what a viewer/OS will actually see, use the composition viewer's **bottom toolbar > "Use Display Color Management"** toggle, and the eyedropper/Info panel to read numeric RGB values rather than trusting the on-screen brightness.
|
||||
|
||||
## Export settings per platform
|
||||
|
||||
Prefer the **Render Queue** (Composition > Add to Render Queue) for ProRes masters, or **File > Export > Add to Adobe Media Encoder Queue** for H.264 web files.
|
||||
|
||||
| Target | Codec / format | Color tag to embed | Notes |
|
||||
|---|---|---|---|
|
||||
| Editing master (FCP/Premiere/Resolve) | **ProRes 422 HQ / 4444** (QuickTime) | Rec.709 | Highest fidelity; avoids H.264 gamma guessing |
|
||||
| Web / `<video>` / social | **H.264** (MP4) via Media Encoder | **Rec.709**, tagged | Set Match Source then override profile; verify in Chrome |
|
||||
| YouTube / Vimeo upload | H.264 high bitrate or ProRes | Rec.709 | Platforms re-encode; correct tag prevents their guess |
|
||||
| Transparency for web | **PNG / ProRes 4444 + alpha** then convert | sRGB | Browsers treat PNG as sRGB |
|
||||
| HDR | ProRes 4444 / HEVC 10-bit | Rec.2020 PQ/HLG | Requires 32 bpc float project |
|
||||
|
||||
In **Adobe Media Encoder**, the QuickTime/ProRes color tag is governed by the AE **Output Module > Color Management** sub-tab. In the Render Queue, click the **Output Module** name > **Color Management** tab and set the output profile to **Rec.709 Gamma 2.4** (do not leave "Preserve RGB" if a shift is occurring).
|
||||
|
||||
## The QuickTime gamma bug — workarounds
|
||||
|
||||
QuickTime Player and any AVFoundation-based player can apply an extra ~1.96 gamma to ProRes/H.264, making files look darker/contrastier than they do in Chrome, Premiere, or Resolve. It is a *player* problem, not a render problem.
|
||||
|
||||
1. **Never grade or approve to QuickTime.** Use Chrome, Premiere, or Resolve as the reference, since those match how the web and other editors display the file.
|
||||
2. For ProRes masters that must look right in QuickTime too, **embed the Rec.709 (Gamma 2.4) tag** via Output Module > Color Management. Correctly tagged ProRes is interpreted consistently by modern macOS.
|
||||
3. If a legacy pipeline still shifts, render a **second 1:1 reference still** (Composition > Save Frame As > File) as PNG and compare numeric values — pixels, not perception.
|
||||
4. Avoid the old "nudge gamma by 1.08 to cancel QuickTime" hacks for new work; they bake a wrong curve that breaks on every correct player. Only use a compensating curve if delivering *exclusively* to a known-broken legacy QuickTime target.
|
||||
|
||||
## Per-player / per-OS gamma reference
|
||||
|
||||
| Environment | Effective transfer assumption | Notes |
|
||||
|---|---|---|
|
||||
| Rec.709 standard display (BT.1886) | **2.4** | The correct broadcast/web display gamma |
|
||||
| sRGB display | **~2.2** (piecewise) | UI, screenshots, PNG |
|
||||
| macOS QuickTime / AVFoundation | **~1.96** | Source of the "QuickTime gamma bug"; brighter/contrast-shifted vs browser |
|
||||
| Chrome / Firefox `<video>` | honors 2.4 / sRGB pipeline | Correct reference for web delivery |
|
||||
| macOS classic (pre-10.6) | 1.8 | Legacy only; ignore for new work |
|
||||
| Windows default | 2.2 | Assumed when file is untagged |
|
||||
|
||||
Takeaway: the *only* reliable cross-environment guarantee is an **explicit embedded tag**. Without it, every player above falls back to its own default and they disagree.
|
||||
|
||||
## Numeric test-patch method (perception-free)
|
||||
|
||||
Eyes adapt; numbers do not. To prove whether a shift exists:
|
||||
|
||||
1. In the comp, add a Solid (Layer > New > Solid) filled with **50% grey: RGB 128,128,128** (or 188,188,188 for a known mid-light patch).
|
||||
2. Note the value AE reports in the **Info panel** when hovering with managed display on.
|
||||
3. Render the file with the intended export settings.
|
||||
4. Re-import the rendered file into a fresh comp (or open in an app with a pixel readout) and sample the same patch.
|
||||
5. If the sampled value differs from 128 by more than ~2-3 levels, a gamma transform is being applied somewhere in the chain. A washed-out look corresponds to the value rising (e.g. 128 → 150+).
|
||||
|
||||
This isolates whether the shift is in the *render* (values changed in the file) vs the *playback* (file values correct, player re-curving).
|
||||
|
||||
## Verify the embedded tag with ffprobe
|
||||
|
||||
```bash
|
||||
ffprobe -v error -select_streams v:0 \
|
||||
-show_entries stream=color_transfer,color_primaries,color_space,color_range \
|
||||
-of default=nk=0 export.mp4
|
||||
```
|
||||
|
||||
Desired for SDR web (Rec.709):
|
||||
|
||||
```
|
||||
color_space=bt709
|
||||
color_primaries=bt709
|
||||
color_transfer=bt709
|
||||
color_range=tv # (limited) for video; pc/full for some web pipelines
|
||||
```
|
||||
|
||||
If `color_transfer=unknown` or fields are absent, the file is untagged → re-export with the tag, or stamp it without re-encoding:
|
||||
|
||||
```bash
|
||||
ffmpeg -i export.mp4 -c copy \
|
||||
-color_primaries bt709 -color_trc bt709 -colorspace bt709 \
|
||||
export_tagged.mp4
|
||||
```
|
||||
|
||||
Note: `-c copy` only writes container/stream metadata; it does not fix pixels that were already baked wrong — use it to *tag*, not to *correct*.
|
||||
|
||||
## Limited vs full range pitfall
|
||||
|
||||
H.264 for video is typically **limited/TV range** (luma 16-235). If AE/AME outputs full-range pixels but the file is tagged limited (or vice versa), blacks crush or wash. Symptoms: milky blacks = full data read as limited; crushed blacks = limited data read as full. Keep range consistent end-to-end and tag it (`color_range`).
|
||||
|
||||
## Quick reference
|
||||
|
||||
| Symptom | Likely cause | Fix |
|
||||
|---|---|---|
|
||||
| Washed-out / milky blacks | Untagged H.264, player adds gamma | Tag Rec.709 in Output Module > Color Management |
|
||||
| Fine in QuickTime, dark in Chrome | QuickTime ~1.96 gamma | Trust Chrome; QuickTime is wrong for web |
|
||||
| Differs macOS vs Windows | No embedded color tag | Embed explicit Rec.709/sRGB tag |
|
||||
| Banding in gradients | 8 bpc project | Project Settings > Depth = 16 bpc |
|
||||
| Glows/blurs look wrong | Non-linear blending | Enable Linearize Working Space |
|
||||
| Screenshots/UI look off | Wrong working space | Use sRGB working space, not Rec.709 |
|
||||
|
||||
## Gotchas
|
||||
|
||||
- "Working Space = None" disables AE color management entirely — the viewer then lies about the final look. Always set an explicit space for managed delivery.
|
||||
- Toggling Linearize Working Space late changes the look of every feather, glow, and screen blend; decide at project start.
|
||||
- AME "Match Source" can silently drop the color tag; verify the exported file's tag (e.g. with `ffprobe -show_streams`, look for `color_transfer`/`color_primaries`).
|
||||
- ProRes is not magic — an untagged ProRes still shifts. The *tag* is what fixes consistency, not the codec.
|
||||
- sRGB and Rec.709 share primaries but differ in transfer (sRGB ~2.2 piecewise vs Rec.709 display 2.4); using the wrong one shifts midtone brightness.
|
||||
|
||||
## Pre-export checklist
|
||||
|
||||
- [ ] Project Settings > Color: Working Space set to the deliverable's space (Rec.709 Gamma 2.4 for SDR video; sRGB for UI/stills).
|
||||
- [ ] Project Settings > Color: Depth = 16 bpc (or 32 for HDR/heavy linear).
|
||||
- [ ] Linearize Working Space decision made at project start (on for glow/blur-heavy comps).
|
||||
- [ ] Display Color Management toggle ON while reviewing, so the viewer reflects final look.
|
||||
- [ ] 50% grey test patch placed and noted before render.
|
||||
- [ ] Output Module > Color Management: explicit output profile = Rec.709 Gamma 2.4 (not "Preserve RGB" when a shift exists).
|
||||
- [ ] Codec chosen per target (ProRes 422 HQ/4444 master, H.264 web).
|
||||
- [ ] Reviewed final in **Chrome / Premiere / Resolve**, not QuickTime.
|
||||
- [ ] `ffprobe` confirms color_primaries/transfer/space = bt709 (or sRGB target) and color_range consistent.
|
||||
- [ ] Re-imported render and re-sampled the grey patch; value matches within ~2-3 levels.
|
||||
|
||||
## When the client only has QuickTime
|
||||
|
||||
If the approval environment is genuinely locked to macOS QuickTime and the file must look right *there*:
|
||||
|
||||
1. Deliver correctly tagged ProRes (modern macOS QuickTime respects Rec.709 tags fairly well).
|
||||
2. If a residual shift remains and cannot be avoided, produce a *separate* QuickTime-targeted file with a measured compensating gamma adjustment — and clearly label it "QuickTime-only; do not use for web." Never let this compensated file become the web master.
|
||||
3. Educate: provide the same file opened in Chrome side-by-side so the difference is attributed to the player, not the work.
|
||||
@@ -0,0 +1,180 @@
|
||||
# Palettes, gradients, interpolation, and grading
|
||||
|
||||
Exact recipes and runnable code. OKLCH notation: `oklch(L C H)`, L in 0-1 perceptual lightness, C chroma (0 to ~0.37), H hue degrees.
|
||||
|
||||
## Palette construction rules
|
||||
|
||||
1. **Count**: 1 primary, 1 accent, 2-3 neutrals. Resist adding hues.
|
||||
2. **Contrast from lightness**: build a 5-9 step ramp by varying L while holding C and H roughly constant, nudging chroma down at the extremes (very light/dark colors can't hold high chroma).
|
||||
3. **Accent placement**: accent hue should sit 90-180deg from the primary on the OKLCH wheel for clean separation; complementary (~180deg) is boldest, analogous (~30deg) is calmest.
|
||||
4. **Neutral tinting**: give neutrals a tiny chroma (0.005-0.02) in the primary's hue family so the frame feels unified, not assembled from separate kits.
|
||||
5. **Dark-scene accents**: high L (0.7-0.85), moderate C (0.12-0.18). Avoid max chroma — it vibrates on dark backgrounds.
|
||||
|
||||
### Generating a tonal ramp (hold hue, vary lightness)
|
||||
|
||||
```
|
||||
oklch(0.97 0.03 264) // 50
|
||||
oklch(0.92 0.06 264) // 100
|
||||
oklch(0.84 0.10 264) // 200
|
||||
oklch(0.74 0.14 264) // 300
|
||||
oklch(0.66 0.18 264) // 400
|
||||
oklch(0.58 0.19 264) // 500 (base)
|
||||
oklch(0.50 0.17 264) // 600
|
||||
oklch(0.40 0.14 264) // 700
|
||||
oklch(0.28 0.10 264) // 800
|
||||
oklch(0.18 0.06 264) // 900
|
||||
```
|
||||
|
||||
Note chroma rises toward the mid-lightness band and falls at both ends — this matches what's physically representable and looks natural.
|
||||
|
||||
### Named starter palettes (OKLCH)
|
||||
|
||||
```
|
||||
// "Midnight product" — confident, techy
|
||||
primary oklch(0.62 0.19 264) accent oklch(0.78 0.17 50)
|
||||
bg oklch(0.16 0.02 264) fg oklch(0.97 0.005 264)
|
||||
|
||||
// "Warm editorial" — premium, soft
|
||||
primary oklch(0.55 0.12 25) accent oklch(0.80 0.10 90)
|
||||
bg oklch(0.96 0.01 60) fg oklch(0.25 0.03 25)
|
||||
|
||||
// "Neon dark" — energetic, bold
|
||||
primary oklch(0.72 0.20 150) accent oklch(0.68 0.24 330)
|
||||
bg oklch(0.14 0.03 280) fg oklch(0.95 0.02 150)
|
||||
```
|
||||
|
||||
## Gradient cookbook
|
||||
|
||||
### Two-stop, vivid (OKLCH)
|
||||
|
||||
```css
|
||||
background: linear-gradient(135deg in oklch, #2b6cff, #ffb02e);
|
||||
/* control the hue arc explicitly */
|
||||
background: linear-gradient(in oklch shorter hue, oklch(0.6 0.2 264), oklch(0.8 0.17 50));
|
||||
```
|
||||
|
||||
`shorter hue` / `longer hue` / `increasing hue` / `decreasing hue` pick the direction around the wheel — `longer hue` produces rainbow sweeps, `shorter` the direct path.
|
||||
|
||||
### Mesh background (stacked radials)
|
||||
|
||||
```css
|
||||
.mesh {
|
||||
background-color: #0b0f1a;
|
||||
background-image:
|
||||
radial-gradient(at 18% 22%, oklch(0.62 0.19 264 / 0.7), transparent 50%),
|
||||
radial-gradient(at 82% 28%, oklch(0.70 0.16 320 / 0.6), transparent 55%),
|
||||
radial-gradient(at 55% 88%, oklch(0.78 0.17 50 / 0.5), transparent 50%),
|
||||
radial-gradient(at 40% 50%, oklch(0.55 0.14 200 / 0.4), transparent 60%);
|
||||
}
|
||||
```
|
||||
|
||||
### Animated drift
|
||||
|
||||
```css
|
||||
.mesh { background-size: 140% 140%; animation: drift 16s ease-in-out infinite alternate; }
|
||||
@keyframes drift {
|
||||
0% { background-position: 0% 0%; }
|
||||
100% { background-position: 12% -8%; }
|
||||
}
|
||||
```
|
||||
|
||||
### Conic
|
||||
|
||||
```css
|
||||
background: conic-gradient(in oklch from 90deg, #2b6cff, #b02eff, #ffb02e, #2b6cff);
|
||||
```
|
||||
|
||||
### Grain overlay (kills banding)
|
||||
|
||||
```html
|
||||
<svg width="0" height="0">
|
||||
<filter id="grain"><feTurbulence type="fractalNoise" baseFrequency="0.8" numOctaves="2"/></filter>
|
||||
</svg>
|
||||
```
|
||||
```css
|
||||
.grain::after {
|
||||
content: ""; position: absolute; inset: 0; pointer-events: none;
|
||||
filter: url(#grain); opacity: 0.04; mix-blend-mode: overlay;
|
||||
}
|
||||
```
|
||||
|
||||
## Perceptual interpolation in code
|
||||
|
||||
### culori (JS) — interpolate and sample
|
||||
|
||||
```js
|
||||
import { interpolate, formatHex, formatCss } from "culori";
|
||||
|
||||
// Interpolate in OKLCH (vivid midpoints, even lightness)
|
||||
const mix = interpolate(["#2b6cff", "#ffb02e"], "oklch");
|
||||
formatHex(mix(0.5)); // vivid mid, not gray
|
||||
|
||||
// Build N stops for an animated transition
|
||||
const stops = Array.from({ length: 60 }, (_, i) => formatCss(mix(i / 59)));
|
||||
|
||||
// Control hue direction
|
||||
import { fixupHueLonger } from "culori";
|
||||
const rainbow = interpolate(["#2b6cff", "#ffb02e"], "oklch", {
|
||||
h: { use: fixupHueLonger },
|
||||
});
|
||||
```
|
||||
|
||||
### d3-interpolate / d3-scale-chromatic
|
||||
|
||||
```js
|
||||
import { interpolateLab, interpolateHcl, quantize } from "d3-interpolate";
|
||||
|
||||
const lab = interpolateLab("#2b6cff", "#ffb02e"); // perceptual, smooth lightness
|
||||
lab(0.5); // mid color
|
||||
const ramp = quantize(interpolateHcl("#2b6cff", "#ffb02e"), 8); // 8 even stops
|
||||
```
|
||||
|
||||
`interpolateLab` and `interpolateHcl` avoid the sRGB gray-midpoint problem; `interpolateRgb` does not — only use RGB interpolation for near-identical colors.
|
||||
|
||||
### Animating a color with @property (CSS, browser interpolates)
|
||||
|
||||
```css
|
||||
@property --from { syntax: "<color>"; initial-value: oklch(0.62 0.19 264); inherits: false; }
|
||||
.swatch { background: var(--from); transition: --from 400ms cubic-bezier(0.16,1,0.3,1); }
|
||||
.swatch.active { --from: oklch(0.78 0.17 50); }
|
||||
```
|
||||
|
||||
Without `@property` registration the color snaps instead of interpolating. The browser interpolates registered `<color>` properties in OKLab by default — perceptually clean for free.
|
||||
|
||||
## Grading order checklist
|
||||
|
||||
Apply in this exact order; reordering changes the result.
|
||||
|
||||
1. **Exposure / white balance** — set overall brightness, neutralize or intentionally tint the cast.
|
||||
2. **Contrast** — set black/white points, expand or compress tonal range.
|
||||
3. **Midtones / saturation** — overall saturation and midtone color shift.
|
||||
4. **Split-tone** — tint shadows and highlights separately. Cinematic default: teal shadows (`hue ~190`), orange highlights (`hue ~40`), kept subtle.
|
||||
5. **Unify** — final overall tint / LUT and a gentle vignette.
|
||||
|
||||
### CSS-filter grade (quick, for web video/canvas)
|
||||
|
||||
```css
|
||||
.graded {
|
||||
filter:
|
||||
brightness(1.02) /* 1: exposure */
|
||||
contrast(1.12) /* 2: contrast */
|
||||
saturate(1.08); /* 3: saturation */
|
||||
}
|
||||
/* 4 split-tone: overlay a teal->orange gradient at low opacity with mix-blend-mode */
|
||||
```
|
||||
|
||||
### Fragment-shader split-tone (GLSL sketch)
|
||||
|
||||
```glsl
|
||||
vec3 graded = color;
|
||||
float lum = dot(graded, vec3(0.2126, 0.7152, 0.0722));
|
||||
vec3 shadowTint = vec3(0.0, 0.45, 0.5); // teal
|
||||
vec3 highlightTint = vec3(1.0, 0.6, 0.2); // orange
|
||||
graded = mix(graded, graded * shadowTint, (1.0 - lum) * 0.12);
|
||||
graded = mix(graded, graded + highlightTint * 0.06, lum);
|
||||
```
|
||||
|
||||
Keep split-tone strength under ~0.15; over-tinting reads as a cheap Instagram filter. Grade the whole piece with the same chain so cuts match.
|
||||
|
||||
---
|
||||
Interpolate color in perceptual space and gradients shift without muddy mids. Built by **[iart.ai](https://iart.ai/?utm_source=github&utm_medium=readme&utm_campaign=motion-design-skills&utm_content=skill_footer&utm_term=color-motion)** — the AI motion agent for editable, on-brand motion graphics.
|
||||
@@ -1,177 +0,0 @@
|
||||
---
|
||||
name: glassmorphism
|
||||
description: This skill should be used when the user asks to "add a glassmorphism effect", "frosted glass UI", "Apple liquid glass style", "frosted blur card", "translucent glass panel animation", "make a frosted nav bar", "build a glass modal/dialog", "animate a glass card on hover", or "add a refracting liquid-glass hero". Covers frosted translucent panels with backdrop-filter blur, edge/specular highlights, SVG liquid-glass refraction, motion on hover/scroll/enter, and accessible reduced-transparency fallbacks.
|
||||
version: 0.1.0
|
||||
---
|
||||
|
||||
# Glassmorphism (Frosted & Liquid Glass)
|
||||
|
||||
Translucent, frosted UI: panels you can see through, blurred so the backdrop reads as soft color, rimmed by a bright edge of light, floating on layered shadow. The 2026 "liquid glass" evolution adds refraction — the background visibly bends through the panel — plus moving specular highlights. The goal is depth and material, not just opacity.
|
||||
|
||||
## When to use
|
||||
|
||||
- Frosted cards, nav bars, sidebars, modals/dialogs, and toolbars over busy/photo backgrounds
|
||||
- Login/hero panels and overlays that should feel layered above the page
|
||||
- Apple-style "liquid glass" heroes: refracting, slowly churning surfaces with a specular sweep
|
||||
- Hover/scroll/enter motion on glass — frost deepening, highlight brightening, the panel lifting
|
||||
- Any place where content needs to read as floating glass while staying legible
|
||||
|
||||
## The four ingredients of believable glass
|
||||
|
||||
Glass is never one property. Every panel needs all four, or it reads as a plain translucent box:
|
||||
|
||||
1. **Frost** — `backdrop-filter: blur()` plus `saturate()` to keep backdrop color vivid through the blur.
|
||||
2. **Translucency** — a `background` with alpha (~0.08–0.18), never fully opaque, never fully clear.
|
||||
3. **Edge of glass** — a hairline border *brighter* than the fill, ideally a lit top-left → dim bottom-right highlight, so the rim catches light.
|
||||
4. **Depth** — layered `box-shadow`: an ambient drop shadow to float it, plus an `inset` top highlight and bottom shade to round the surface.
|
||||
|
||||
```css
|
||||
.glass {
|
||||
background: rgba(255, 255, 255, 0.12);
|
||||
backdrop-filter: blur(16px) saturate(160%);
|
||||
-webkit-backdrop-filter: blur(16px) saturate(160%); /* Safari needs the prefix */
|
||||
border-radius: 20px;
|
||||
border: 1px solid rgba(255, 255, 255, 0.25);
|
||||
box-shadow:
|
||||
0 8px 32px rgba(0, 0, 0, 0.25), /* float */
|
||||
inset 0 1px 0 rgba(255, 255, 255, 0.35), /* top highlight */
|
||||
inset 0 -1px 0 rgba(0, 0, 0, 0.12); /* bottom shade */
|
||||
}
|
||||
```
|
||||
|
||||
Frost tiers: light UI chrome `blur(8–12px)` / alpha `0.08–0.14`; heavy modal/login `blur(24–40px)` / alpha `0.10–0.18`. Dark glass: fill `rgba(0,0,0,0.3)`, softer top highlight.
|
||||
|
||||
**`backdrop-filter` only blurs content that sits behind the element.** Over a flat background color it does nothing visible — glass needs a busy backdrop (image, gradient, video) to frost.
|
||||
|
||||
## Specular edge highlight and anti-banding grain
|
||||
|
||||
A flat border is dead. Draw a masked 1px ring with a lit corner via `::before`, and dither away gradient **banding** (stepped contour lines under heavy blur) with a faint `feTurbulence` noise overlay via `::after` at `opacity ≤ 0.06`. Full masked-border and inline-noise recipes are in `references/glass-recipes.md`.
|
||||
|
||||
## Motion: animate the glass, not the geometry
|
||||
|
||||
Animate the *qualities* of the glass — frost deepening, highlight brightening, the panel lifting — so it reads as the surface "leaning into the light."
|
||||
|
||||
```css
|
||||
.glass {
|
||||
transition: backdrop-filter .4s ease, background .4s ease,
|
||||
box-shadow .4s ease, transform .4s cubic-bezier(.16,1,.3,1);
|
||||
}
|
||||
.glass:hover {
|
||||
backdrop-filter: blur(24px) saturate(180%);
|
||||
background: rgba(255,255,255,.18);
|
||||
transform: translateY(-4px);
|
||||
box-shadow: 0 16px 48px rgba(0,0,0,.3), inset 0 1px 0 rgba(255,255,255,.5);
|
||||
}
|
||||
```
|
||||
|
||||
- **Entrance** (frost resolving from clear): pair a `[data-enter]` transition with `@starting-style { backdrop-filter: blur(0); opacity: 0; transform: translateY(16px) }`.
|
||||
- **Specular sweep**: a skewed white gradient animated across the surface on hover or as a slow ambient loop.
|
||||
- **Caveat**: animating the blur *radius* is the most expensive thing here — the backdrop is re-blurred every frame. If hover janks, animate `transform`/`box-shadow`/`background` (cheap) and keep the blur delta small or snap it.
|
||||
|
||||
## Liquid glass — SVG refraction (the 2026 look)
|
||||
|
||||
Bend the background through the panel like a thick lens: drive `feDisplacementMap` from animated `feTurbulence`, applied via `filter` (it distorts the element's own pixels) layered over a `backdrop-filter` frost.
|
||||
|
||||
```html
|
||||
<svg width="0" height="0" style="position:absolute"><filter id="liquid-glass">
|
||||
<feTurbulence type="fractalNoise" baseFrequency="0.008 0.012" numOctaves="2" seed="3" result="n">
|
||||
<animate attributeName="baseFrequency" dur="18s"
|
||||
values="0.008 0.012;0.012 0.008;0.008 0.012" repeatCount="indefinite"/>
|
||||
</feTurbulence>
|
||||
<feDisplacementMap in="SourceGraphic" in2="n" scale="22" xChannelSelector="R" yChannelSelector="G"/>
|
||||
</filter></svg>
|
||||
```
|
||||
|
||||
`scale` = refraction strength (8–14 subtle, 20–30 pronounced, >40 molten). Lower `baseFrequency` = larger, slower waves (more liquid). Keep the `animate` `dur` long (12–20s) so it breathes. These filters are heavy — use on **one** hero element, not a grid.
|
||||
|
||||
## Performance — backdrop-filter is expensive
|
||||
|
||||
- Each glass element re-samples and blurs everything behind it. **Limit the count**; a dozen on screen tanks scroll FPS.
|
||||
- Promote heavy glass to its own layer (`transform: translateZ(0)` or `will-change: transform`), and remove `will-change` after the animation.
|
||||
- Don't stack `backdrop-filter` elements over each other — nested blur re-blurs the blur (quadratic cost).
|
||||
- Big radii (>40px) over large areas are the worst case; cap radius and panel size.
|
||||
|
||||
## Accessibility — non-negotiable
|
||||
|
||||
Glass is decoration; content must stay legible and the effect must be defeatable.
|
||||
|
||||
```css
|
||||
@media (prefers-reduced-transparency: reduce) {
|
||||
.glass { background: #1a1a2e; backdrop-filter: none; -webkit-backdrop-filter: none; }
|
||||
.glass::after { display: none; } /* drop grain */
|
||||
}
|
||||
@media (prefers-reduced-motion: reduce) {
|
||||
.glass { transition: none; }
|
||||
.liquid { filter: none; } /* stop the refraction churn */
|
||||
}
|
||||
@supports not (backdrop-filter: blur(1px)) {
|
||||
.glass { background: rgba(30,30,50,.85); } /* opaque-enough fallback */
|
||||
}
|
||||
```
|
||||
|
||||
**Contrast over busy backgrounds**: translucent panels over photos can drop text below WCAG. Add a semi-opaque scrim or darkening gradient *under* the text, optionally `text-shadow: 0 1px 2px rgba(0,0,0,.4)`, and verify ≥ 4.5:1 body / ≥ 3:1 large against the *brightest* region of the backdrop.
|
||||
|
||||
## Deliver & verify (standalone HTML)
|
||||
|
||||
> **Packaged helper** (`scripts/`): `scripts/seek-shot.sh anim.html 0 1.5 3` freezes the `?t=N` harness and screenshots each moment; `scripts/contact-sheet.sh sheet.png frame-*.png` tiles them for one-glance review. See `scripts/README.md`.
|
||||
|
||||
For a self-contained glass demo (card, nav, modal, liquid-glass hero) the deliverable is **one HTML file that opens directly in a browser** — markup, CSS, and (if liquid) one inline SVG filter, no build step. A single file is the right tier for a glass surface; don't reach for a bundler. The panel **must overlap a real backdrop** (drop in a photo or gradient) or there is nothing to frost and the demo lies.
|
||||
|
||||
**Output contract:**
|
||||
- One `.html` file: a busy backdrop, your glass markup, the CSS (frost + edge highlight + grain + shadows), and any inline SVG `feDisplacementMap` filter.
|
||||
- A way to land on the **resolved state** *and* a **frozen frame** of any loop — glass verifies by both state (rest/hover/enter) and time (the sweep/refraction).
|
||||
- Include the freeze harness below so any moment can be pinned for inspection.
|
||||
|
||||
**Seek harness — pin a deterministic state + frame.** `?state=hover` forces the hover look; `?t=N` freezes CSS animations and the SVG refraction at `N` seconds, so a screenshot lands on a still, deterministic frame:
|
||||
|
||||
```html
|
||||
<script>
|
||||
const p = new URLSearchParams(location.search);
|
||||
const state = p.get("state");
|
||||
if (state) document.documentElement.dataset.state = state; // CSS keys off :root[data-state="hover"]
|
||||
const t = p.get("t");
|
||||
if (t !== null) {
|
||||
document.getAnimations().forEach(a => { a.currentTime = parseFloat(t)*1000; a.pause(); }); // freeze CSS sweep
|
||||
const svg = document.querySelector("svg");
|
||||
svg?.pauseAnimations?.(); svg?.setCurrentTime?.(parseFloat(t)); // freeze refraction
|
||||
}
|
||||
window.__ready = true;
|
||||
</script>
|
||||
```
|
||||
|
||||
**Verify loop — render → set state/freeze → screenshot → check:** open each meaningful state (`?state=rest`, `?state=hover`) and a frozen loop frame (`?t=2`), screenshot, and confirm the glass **reads as glass** — blur and edge highlight visibly present, no color banding, text contrast holds over the backdrop — plus check **artifacts** (flat box because the backdrop is plain color, missing `-webkit-` prefix in Safari, refraction too strong/molten, jank from animating blur). Then load `prefers-reduced-transparency` and confirm the **solid fallback renders** legibly. Any headless tool works:
|
||||
|
||||
```bash
|
||||
npx playwright screenshot --wait-for-timeout=500 "file://$PWD/glass.html?state=hover" hover.png
|
||||
npx playwright screenshot --wait-for-timeout=500 "file://$PWD/glass.html?t=2" loop.png
|
||||
```
|
||||
|
||||
To check the fallback headlessly, emulate the media feature (e.g. Playwright `--color-scheme`-style flags, or a `?reduced=1` query that toggles a class mirroring the media query) and screenshot that the panel is solid and readable.
|
||||
|
||||
**Before you finish:**
|
||||
1. Opens standalone — no console errors; the glass overlaps a real busy backdrop, not a flat color.
|
||||
2. Reads as glass — blur + bright edge highlight both visible, layered shadow floats it, no banding (grain present).
|
||||
3. Text contrast holds over the brightest part of the backdrop (≥ 4.5:1 body).
|
||||
4. `?state=` / `?t=N` freeze lands a deterministic, settled frame.
|
||||
5. `prefers-reduced-transparency` → solid opaque panel; `prefers-reduced-motion` → refraction/sweep stopped; `@supports` fallback for no `backdrop-filter`.
|
||||
6. Performance sane — glass count limited, blur not animated on a janky path, liquid refraction on one element only.
|
||||
|
||||
## Quick reference
|
||||
|
||||
| Need | Approach |
|
||||
|------|----------|
|
||||
| Base frost | `backdrop-filter: blur(16px) saturate(160%)` + alpha bg |
|
||||
| Edge of glass | brighter `border` + masked `::before` lit-corner ring |
|
||||
| Float / depth | `box-shadow` drop + `inset` top highlight & bottom shade |
|
||||
| Kill banding | `feTurbulence` noise `::after`, `opacity ≤ .06` |
|
||||
| Hover motion | transition `transform`/`box-shadow`/`background`, small blur delta |
|
||||
| Entrance | `@starting-style { backdrop-filter: blur(0); opacity:0 }` |
|
||||
| Liquid refraction | `feDisplacementMap` ← animated `feTurbulence`, via `filter` |
|
||||
| Specular sweep | skewed white gradient animated across surface |
|
||||
| Safari | always pair `-webkit-backdrop-filter` |
|
||||
| Reduced transparency | solid opaque panel, drop grain |
|
||||
| No backdrop-filter | `@supports not (...)` opaque-enough fallback |
|
||||
|
||||
## Reference files
|
||||
|
||||
- `references/glass-recipes.md` — full copy-paste recipes: base glass card with tiers, the masked specular edge ring, anti-banding grain, hover/enter/scroll motion, the specular sweep, the SVG `feDisplacementMap`/`feTurbulence` liquid-glass filter with tuning knobs, performance rules, the reduced-transparency/reduced-motion/`@supports` fallbacks, contrast defenses, and the standalone freeze harness.
|
||||
@@ -1,242 +0,0 @@
|
||||
# Glassmorphism Recipes
|
||||
|
||||
Copy-paste recipes for frosted translucent panels, the "edge of glass" highlight, animated liquid-glass refraction, and the reduced-transparency fallback. All standalone CSS + optional inline SVG — no build step.
|
||||
|
||||
## 1. The base glass card
|
||||
|
||||
The four ingredients of believable glass: **blur** (frost), **translucency** (you see through it), **edge highlight** (light catches the rim), **layered shadow** (it floats). Plus a touch of `saturate()` so the backdrop reads vivid through the frost.
|
||||
|
||||
```css
|
||||
.glass {
|
||||
/* translucency — never fully opaque, never fully clear */
|
||||
background: rgba(255, 255, 255, 0.12);
|
||||
/* frost: blur the backdrop, lift saturation so color survives the blur */
|
||||
backdrop-filter: blur(16px) saturate(160%);
|
||||
-webkit-backdrop-filter: blur(16px) saturate(160%); /* Safari still needs the prefix */
|
||||
border-radius: 20px;
|
||||
/* edge of glass: a hairline border slightly brighter than the fill */
|
||||
border: 1px solid rgba(255, 255, 255, 0.25);
|
||||
/* depth: ambient drop + a top inner highlight + a bottom inner shade */
|
||||
box-shadow:
|
||||
0 8px 32px rgba(0, 0, 0, 0.25),
|
||||
inset 0 1px 0 rgba(255, 255, 255, 0.35),
|
||||
inset 0 -1px 0 rgba(0, 0, 0, 0.12);
|
||||
}
|
||||
```
|
||||
|
||||
Tuning by tier:
|
||||
- **Light frost** (UI chrome over content): `blur(8–12px)`, alpha `0.08–0.14`.
|
||||
- **Heavy frost** (modal scrim, login card): `blur(24–40px)`, alpha `0.10–0.18`.
|
||||
- Dark glass: swap the fill to `rgba(0,0,0,0.3)` and the top inner highlight to a softer white.
|
||||
|
||||
`backdrop-filter` only has anything to blur if there is content **behind** the element — it must overlap a busy background (image, gradient, video). On a flat color it looks like a plain translucent box.
|
||||
|
||||
## 2. The specular edge highlight (the rim of light)
|
||||
|
||||
A single border is flat. Real glass catches a bright sweep along the top-left edge and falls off. Layer a soft conic/linear highlight via a pseudo-element with a masked border.
|
||||
|
||||
```css
|
||||
.glass {
|
||||
position: relative;
|
||||
isolation: isolate; /* keep the highlight blend local */
|
||||
}
|
||||
.glass::before {
|
||||
content: "";
|
||||
position: absolute;
|
||||
inset: 0;
|
||||
border-radius: inherit;
|
||||
padding: 1px; /* border thickness */
|
||||
background: linear-gradient(
|
||||
135deg,
|
||||
rgba(255, 255, 255, 0.7),
|
||||
rgba(255, 255, 255, 0) 40%,
|
||||
rgba(255, 255, 255, 0) 60%,
|
||||
rgba(255, 255, 255, 0.25)
|
||||
);
|
||||
/* mask trick: show only the 1px ring, punch out the interior */
|
||||
-webkit-mask:
|
||||
linear-gradient(#000 0 0) content-box,
|
||||
linear-gradient(#000 0 0);
|
||||
-webkit-mask-composite: xor;
|
||||
mask-composite: exclude;
|
||||
pointer-events: none;
|
||||
}
|
||||
```
|
||||
|
||||
This gives the panel a lit top-left corner and a dim bottom-right, the cue the brain reads as "curved glass under a light."
|
||||
|
||||
## 3. Kill banding with grain
|
||||
|
||||
Heavy `blur()` over a smooth gradient produces visible color **banding** (stepped contour lines). A faint noise overlay dithers it away.
|
||||
|
||||
```css
|
||||
.glass::after {
|
||||
content: "";
|
||||
position: absolute;
|
||||
inset: 0;
|
||||
border-radius: inherit;
|
||||
pointer-events: none;
|
||||
opacity: 0.04; /* barely there */
|
||||
mix-blend-mode: overlay;
|
||||
background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='120' height='120'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
|
||||
}
|
||||
```
|
||||
|
||||
`feTurbulence` generates the noise tile inline — no asset file. Keep opacity ≤ 0.06 or it reads as texture, not dither.
|
||||
|
||||
## 4. Motion: animate the glass on hover / enter / scroll
|
||||
|
||||
Animate the *qualities* of the glass, not its geometry. Frost deepening and the highlight brightening on hover reads as the panel "leaning into the light."
|
||||
|
||||
```css
|
||||
.glass {
|
||||
transition:
|
||||
backdrop-filter 0.4s ease,
|
||||
background 0.4s ease,
|
||||
box-shadow 0.4s ease,
|
||||
transform 0.4s cubic-bezier(0.16, 1, 0.3, 1);
|
||||
}
|
||||
.glass:hover {
|
||||
backdrop-filter: blur(24px) saturate(180%);
|
||||
background: rgba(255, 255, 255, 0.18);
|
||||
transform: translateY(-4px);
|
||||
box-shadow:
|
||||
0 16px 48px rgba(0, 0, 0, 0.3),
|
||||
inset 0 1px 0 rgba(255, 255, 255, 0.5);
|
||||
}
|
||||
```
|
||||
|
||||
Caveat: animating `backdrop-filter` itself is the most expensive thing here — the backdrop is re-sampled and re-blurred every frame. If hover feels janky, animate only `transform` + `box-shadow` + `background` (cheaper) and snap the blur, or keep the blur change small.
|
||||
|
||||
**Entrance** (frost resolving in) reads beautifully with `@starting-style`:
|
||||
|
||||
```css
|
||||
.glass[data-enter] {
|
||||
transition: opacity 0.5s ease, backdrop-filter 0.6s ease, transform 0.5s ease;
|
||||
}
|
||||
@starting-style {
|
||||
.glass[data-enter] {
|
||||
opacity: 0;
|
||||
backdrop-filter: blur(0px) saturate(100%);
|
||||
transform: translateY(16px) scale(0.98);
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
**Specular sweep** — a moving glint across the surface on hover or as an ambient loop:
|
||||
|
||||
```css
|
||||
.glass .sweep {
|
||||
position: absolute; inset: 0; border-radius: inherit; overflow: hidden; pointer-events: none;
|
||||
}
|
||||
.glass .sweep::before {
|
||||
content: ""; position: absolute; top: 0; left: -60%; width: 50%; height: 100%;
|
||||
background: linear-gradient(105deg, transparent, rgba(255,255,255,0.35), transparent);
|
||||
transform: skewX(-15deg);
|
||||
animation: sweep 4s ease-in-out infinite;
|
||||
}
|
||||
@keyframes sweep { 0%,100% { left: -60%; } 50% { left: 110%; } }
|
||||
```
|
||||
|
||||
## 5. Liquid glass — SVG refraction (the 2026 look)
|
||||
|
||||
Apple-style "liquid glass" bends the background as if seen through a thick, wobbling lens. Drive a `feDisplacementMap` from animated `feTurbulence` and apply it via `filter` (note: `filter`, not `backdrop-filter` — it distorts the element's own rendered content; layer it over a `backdrop-filter` frost for the full effect).
|
||||
|
||||
```html
|
||||
<svg width="0" height="0" style="position:absolute">
|
||||
<filter id="liquid-glass">
|
||||
<feTurbulence type="fractalNoise" baseFrequency="0.008 0.012"
|
||||
numOctaves="2" seed="3" result="noise">
|
||||
<!-- animate the field so the refraction slowly churns -->
|
||||
<animate attributeName="baseFrequency"
|
||||
dur="18s" values="0.008 0.012; 0.012 0.008; 0.008 0.012"
|
||||
repeatCount="indefinite"/>
|
||||
</feTurbulence>
|
||||
<feDisplacementMap in="SourceGraphic" in2="noise"
|
||||
scale="22" xChannelSelector="R" yChannelSelector="G"/>
|
||||
</filter>
|
||||
</svg>
|
||||
```
|
||||
|
||||
```css
|
||||
.liquid {
|
||||
backdrop-filter: blur(6px) saturate(150%); /* light frost under the refraction */
|
||||
filter: url(#liquid-glass); /* the lens distortion */
|
||||
}
|
||||
```
|
||||
|
||||
Knobs:
|
||||
- `scale` on `feDisplacementMap` = refraction strength. 8–14 = subtle ripple; 20–30 = pronounced lens; >40 = molten.
|
||||
- Lower `baseFrequency` = larger, slower waves (more "liquid"); higher = tight, busy ripples.
|
||||
- Animate `baseFrequency` (above) or `scale` for a living surface. Keep `dur` long (12–20s) so it breathes rather than shimmers.
|
||||
|
||||
Cost warning: SVG displacement filters are heavy and force off-GPU paths in some browsers. Use on **one** hero element, not a grid of cards. Test on a mid-range laptop; drop to plain `backdrop-filter` if frames stutter.
|
||||
|
||||
## 6. Performance — backdrop-filter is expensive
|
||||
|
||||
- Each `backdrop-filter` element re-samples and blurs everything behind it. **Limit the count** — a dozen glass cards on screen will tank scroll FPS.
|
||||
- Promote heavy glass to its own compositor layer: `transform: translateZ(0)` or `will-change: transform` (remove `will-change` after the animation; leaving it on wastes memory).
|
||||
- Avoid stacking `backdrop-filter` elements over each other (nested blur re-blurs the blur — quadratic cost).
|
||||
- Prefer animating `transform`/`opacity`/`box-shadow` over animating the blur radius. If you must animate blur, keep the radius delta small.
|
||||
- Big blur radii (>40px) over large areas are the single worst case; cap the radius and the panel size.
|
||||
|
||||
## 7. Accessibility — non-negotiable
|
||||
|
||||
Glass is decorative; the content on it must stay legible and the effect must be defeatable.
|
||||
|
||||
**Honor reduced transparency and reduced motion** — fall back to a solid, opaque panel:
|
||||
|
||||
```css
|
||||
@media (prefers-reduced-transparency: reduce) {
|
||||
.glass {
|
||||
background: #1a1a2e; /* solid, accessible panel */
|
||||
backdrop-filter: none;
|
||||
-webkit-backdrop-filter: none;
|
||||
border-color: rgba(255, 255, 255, 0.15);
|
||||
}
|
||||
.glass::after { display: none; } /* drop grain/noise */
|
||||
}
|
||||
|
||||
@media (prefers-reduced-motion: reduce) {
|
||||
.glass, .glass .sweep::before { transition: none; animation: none; }
|
||||
.liquid { filter: none; } /* stop the churning refraction */
|
||||
}
|
||||
```
|
||||
|
||||
**Contrast over busy backgrounds.** Translucent panels over photos can drop text below WCAG contrast. Defenses:
|
||||
- Put a contrast floor *under* the text: a semi-opaque scrim or a darkening gradient inside the panel.
|
||||
- Add `text-shadow: 0 1px 2px rgba(0,0,0,0.4)` to body text on glass.
|
||||
- Target ≥ 4.5:1 for body text, ≥ 3:1 for large text — and verify against the *brightest* region of the backdrop, not the average.
|
||||
|
||||
**Feature fallback** for browsers without `backdrop-filter`:
|
||||
|
||||
```css
|
||||
@supports not (backdrop-filter: blur(1px)) {
|
||||
.glass { background: rgba(30, 30, 50, 0.85); } /* opaque-enough fallback */
|
||||
}
|
||||
```
|
||||
|
||||
## 8. Standalone freeze harness
|
||||
|
||||
Glass demos verify by *state* (rest / hover / enter) and *time* (the sweep/refraction loop). Wire both so a screenshot lands deterministically:
|
||||
|
||||
```html
|
||||
<script>
|
||||
const p = new URLSearchParams(location.search);
|
||||
const state = p.get("state"); // ?state=hover → force the hover look
|
||||
if (state) document.documentElement.dataset.state = state;
|
||||
const t = p.get("t"); // ?t=2 → freeze CSS animations at 2s
|
||||
if (t !== null) {
|
||||
document.getAnimations().forEach(a => { a.currentTime = parseFloat(t) * 1000; a.pause(); });
|
||||
// SVG SMIL (the <animate>): pin the refraction frame too
|
||||
document.querySelector("svg")?.pauseAnimations?.();
|
||||
document.querySelector("svg")?.setCurrentTime?.(parseFloat(t));
|
||||
}
|
||||
window.__ready = true;
|
||||
</script>
|
||||
```
|
||||
|
||||
CSS drives the forced state: `:root[data-state="hover"] .glass { /* hover values */ }`.
|
||||
|
||||
---
|
||||
Frosted glass that reads as glass — blur, edge light, and refraction, with a clean fallback. Built by **[iart.ai](https://iart.ai/?utm_source=github&utm_medium=readme&utm_campaign=web-animation-skills&utm_content=skill_footer&utm_term=glassmorphism)** — the AI motion agent for editable, on-brand motion graphics.
|
||||
@@ -1,225 +0,0 @@
|
||||
---
|
||||
name: gsap-web
|
||||
description: This skill should be used when the user asks to "build a scroll animation", "add ScrollTrigger", "pin a section while scrolling", "scrub an animation to scroll", "create a hero timeline", "do a horizontal scroll section", "split text and animate words", "animate a layout change with GSAP Flip", "sync ScrollTrigger with Lenis", "Lenis smooth scroll jittery", "ScrollTrigger markers drift", "ScrollTrigger pins break with Lenis/Locomotive", or "set up smooth scroll with GSAP pinning". Covers GSAP timelines, ScrollTrigger, SplitText, Flip, and Lenis/Locomotive smooth-scroll sync for code-driven web motion.
|
||||
version: 0.1.0
|
||||
---
|
||||
|
||||
# GSAP for the Web
|
||||
|
||||
GSAP (GreenSock Animation Platform) is the workhorse for code-driven web motion: sequenced timelines, scroll-driven storytelling, text reveals, and layout transitions. As of GSAP 3.12+, every plugin (ScrollTrigger, SplitText, Flip, MotionPath, MorphSVG, Draggable, Observer) is 100% free, including for commercial use.
|
||||
|
||||
## When to use
|
||||
|
||||
- Scroll-driven storytelling: pinned sections, parallax, progress scrubbing, horizontal scroll
|
||||
- Sequenced hero animations and complex multi-element timelines with precise overlap control
|
||||
- Text reveals split into chars/words/lines (SplitText)
|
||||
- Layout transitions where an element changes position/size/parent (Flip)
|
||||
- Any motion needing fine timing control, easing precision, or imperative orchestration
|
||||
|
||||
## Install and register
|
||||
|
||||
```js
|
||||
import gsap from "gsap";
|
||||
import { ScrollTrigger } from "gsap/ScrollTrigger";
|
||||
import { SplitText } from "gsap/SplitText";
|
||||
import { Flip } from "gsap/Flip";
|
||||
|
||||
gsap.registerPlugin(ScrollTrigger, SplitText, Flip);
|
||||
```
|
||||
|
||||
Plugins MUST be registered before use or they silently no-op. With a bundler, register once at app entry.
|
||||
|
||||
## Core techniques
|
||||
|
||||
### Timelines first
|
||||
|
||||
Prefer one timeline over many independent tweens — it gives a single playhead, relative positioning, and easy reversal.
|
||||
|
||||
```js
|
||||
const tl = gsap.timeline({ defaults: { ease: "power3.out", duration: 0.6 } });
|
||||
tl.from(".title", { yPercent: 100, opacity: 0 })
|
||||
.from(".sub", { y: 20, opacity: 0 }, "-=0.3") // start 0.3s before prev ends
|
||||
.from(".cta", { scale: 0.9, opacity: 0 }, "<"); // align to prev tween START
|
||||
```
|
||||
|
||||
Position parameter cheat sheet:
|
||||
- `"+=0.5"` / `"-=0.3"` — relative to the end of the timeline (gap / overlap)
|
||||
- `"<"` — start of the previous tween; `">"` — end of the previous tween
|
||||
- `"<0.2"` — 0.2s after the previous tween's start
|
||||
- `"myLabel"` — at a named label added via `tl.addLabel("myLabel")`
|
||||
|
||||
Use `.from()` for entrances (animates FROM the given values TO current CSS), `.to()` for exits, `.fromTo()` when both ends must be explicit (most robust against re-runs).
|
||||
|
||||
### gsap.to vs set vs quickTo
|
||||
|
||||
```js
|
||||
gsap.set(el, { autoAlpha: 0 }); // instant, no tween (autoAlpha = opacity + visibility)
|
||||
const xTo = gsap.quickTo(el, "x", { duration: 0.4, ease: "power3" });
|
||||
window.addEventListener("pointermove", (e) => xTo(e.clientX)); // fast repeated updates
|
||||
```
|
||||
|
||||
`autoAlpha` is preferred over raw `opacity` because it also toggles `visibility:hidden` at 0, removing the element from hit-testing.
|
||||
|
||||
### ScrollTrigger basics
|
||||
|
||||
```js
|
||||
gsap.to(".panel", {
|
||||
xPercent: -100,
|
||||
ease: "none",
|
||||
scrollTrigger: {
|
||||
trigger: ".wrap",
|
||||
start: "top top", // when trigger top hits viewport top
|
||||
end: "+=2000", // 2000px of scroll distance
|
||||
pin: true, // freeze .wrap while the tween plays
|
||||
scrub: 1, // tie progress to scrollbar (1 = 1s catch-up smoothing)
|
||||
markers: true, // dev-only visual markers — remove for prod
|
||||
},
|
||||
});
|
||||
```
|
||||
|
||||
Key semantics:
|
||||
- `start`/`end` take `"triggerPos viewportPos"` (e.g. `"top center"`) or `"+=px"`.
|
||||
- `scrub: true` locks animation progress to scroll exactly; `scrub: <number>` adds smoothing lag.
|
||||
- `toggleActions: "play pause resume reverse"` controls onEnter/onLeave/onEnterBack/onLeaveBack for non-scrubbed triggers.
|
||||
- Use `ease: "none"` for scrubbed tweens so motion tracks scroll linearly.
|
||||
|
||||
### Smooth scroll (Lenis) + ScrollTrigger
|
||||
|
||||
Pairing Lenis (or Locomotive) smooth scrolling with ScrollTrigger desyncs unless both run on one loop. Lenis smooths scroll on its own rAF while ScrollTrigger reads scroll on GSAP's ticker; when they tick independently ScrollTrigger samples a stale position. The fix: drive Lenis from GSAP's ticker and update ScrollTrigger on every Lenis scroll.
|
||||
|
||||
```js
|
||||
import Lenis from "lenis";
|
||||
|
||||
const lenis = new Lenis({ duration: 1.2, smoothWheel: true });
|
||||
|
||||
lenis.on("scroll", ScrollTrigger.update); // 1. update ScrollTrigger on every Lenis scroll
|
||||
gsap.ticker.add((t) => lenis.raf(t * 1000)); // 2. one loop: ticker drives Lenis (seconds → ms)
|
||||
gsap.ticker.lagSmoothing(0); // 3. stop GSAP catch-up jitter on heavy frames
|
||||
```
|
||||
|
||||
Critical: `gsap.ticker` passes time in **seconds**, `lenis.raf()` wants **milliseconds** — multiply by 1000. Do NOT also run a standalone `requestAnimationFrame(raf)` loop for Lenis; that double-drives it.
|
||||
|
||||
Common bugs:
|
||||
- **Jitter/stutter** — a leftover `requestAnimationFrame(raf)` loop competing with the ticker, or missing `lagSmoothing(0)`. Remove the rogue loop; set lag smoothing to 0.
|
||||
- **Markers drift** from their triggers — `ScrollTrigger.update` is not subscribed to `lenis.on("scroll", …)`.
|
||||
- **Pins break** — under Lenis do NOT set a `scrollerProxy` (it scrolls the document). Under Locomotive you MUST wire `scrollerProxy` + `pinType` and set `scroller:` on every trigger.
|
||||
- **Scroll stuck / flipped direction** — missing the `* 1000` unit conversion, or two loops out of order.
|
||||
|
||||
Cleanup on SPA unmount: `gsap.ticker.remove(update)` + `lenis.destroy()`, else loops stack per navigation. Gate behind `prefers-reduced-motion` (skip Lenis, run native scroll). Full Lenis + Locomotive wiring, anchor-link routing, `data-lenis-prevent`, React (`useGSAP`/`useEffect`), and a symptom→cause table are in `references/scrolltrigger-lenis.md`.
|
||||
|
||||
### SplitText (text reveal)
|
||||
|
||||
```js
|
||||
const split = SplitText.create(".headline", { type: "lines, words", linesClass: "line" });
|
||||
gsap.from(split.lines, { yPercent: 100, opacity: 0, stagger: 0.08, duration: 0.7, ease: "power4.out" });
|
||||
```
|
||||
|
||||
Gotchas:
|
||||
- Wrap line-mask reveals: set `overflow: hidden` on the line wrapper so `yPercent: 100` hides cleanly. Add `autoSplit: true` (GSAP 3.13+) to re-split on font load / resize.
|
||||
- Call `split.revert()` before re-splitting or on unmount to restore original DOM and avoid duplicated nodes.
|
||||
- Always split AFTER web fonts load (`document.fonts.ready.then(...)`) to prevent wrong line breaks.
|
||||
|
||||
### Flip (layout transitions)
|
||||
|
||||
Flip records state, lets the DOM change instantly, then animates the visual difference (FLIP technique). Ideal for grid<->list, expanding cards, and reparenting.
|
||||
|
||||
```js
|
||||
const state = Flip.getState(".item"); // 1. capture BEFORE
|
||||
container.classList.toggle("grid"); // 2. mutate DOM/CSS (instant)
|
||||
Flip.from(state, { // 3. animate the delta
|
||||
duration: 0.6, ease: "power2.inOut", stagger: 0.05,
|
||||
absolute: true, // take items out of flow during move (prevents reflow jitter)
|
||||
});
|
||||
```
|
||||
|
||||
### Easing quick guide
|
||||
|
||||
- `power2/3.out` — entrances (fast then settle)
|
||||
- `power2.inOut` — moves between two on-screen states
|
||||
- `back.out(1.7)` — overshoot/pop (number = overshoot amount)
|
||||
- `elastic.out(1, 0.3)` — bouncy, use sparingly
|
||||
- `none` — scrubbed scroll tweens
|
||||
- `steps(n)` — sprite/stepped motion
|
||||
- Custom cubic-bezier equivalent: `CustomEase.create("x", "M0,0 C0.2,0 0,1 1,1")` (CustomEase is free)
|
||||
|
||||
## Performance and cleanup
|
||||
|
||||
- Animate `transform` (`x/y/xPercent/scale/rotation`) and `opacity` only — they are GPU-composited and skip layout/paint. Avoid animating `top/left/width/height`.
|
||||
- Set `will-change: transform` on heavy/pinned elements; remove after.
|
||||
- Batch many similar scroll reveals with `ScrollTrigger.batch()` instead of one trigger per element.
|
||||
- After a viewport/content change, call `ScrollTrigger.refresh()`.
|
||||
|
||||
SPA / framework cleanup is mandatory — orphaned triggers cause memory leaks and ghost pinning. Use `gsap.context()` (or `useGSAP` from `@gsap/react`):
|
||||
|
||||
```js
|
||||
useEffect(() => {
|
||||
const ctx = gsap.context(() => {
|
||||
// all gsap + ScrollTrigger code here
|
||||
}, rootRef);
|
||||
return () => ctx.revert(); // kills tweens, triggers, and reverts inline styles
|
||||
}, []);
|
||||
```
|
||||
|
||||
## Deliver & verify (standalone HTML)
|
||||
|
||||
> **Packaged helper** (`scripts/`): `scripts/seek-shot.sh anim.html 0 1.5 3` freezes the `?t=N` harness and screenshots each moment; `scripts/contact-sheet.sh sheet.png frame-*.png` tiles them for one-glance review. See `scripts/README.md`.
|
||||
|
||||
For a self-contained animation (hero, reveal, loop, micro-scene) the deliverable is **one HTML file that opens directly in a browser** — no build step, no framework, no render pipeline. Match the deliverable to the weight of the work: a single file is the right tier for web motion; don't reach for a bundler when one file does the job.
|
||||
|
||||
**Output contract:**
|
||||
- One `.html` file: GSAP + plugins from CDN, your markup, and the animation in one inline `<script>`.
|
||||
- All motion on **one master timeline** (`const tl = gsap.timeline()`) — a single playhead you can seek.
|
||||
- Include the seek harness below so any moment can be frozen for inspection.
|
||||
|
||||
**Seek harness — freeze an exact moment for screenshots.** The web parallel of a video player's frame-pin: `?t=N` seeks the master timeline to `N` seconds and pauses, so a screenshot lands on a still, deterministic frame.
|
||||
|
||||
```html
|
||||
<script>
|
||||
// ... build your master timeline as `tl` ...
|
||||
const t = new URLSearchParams(location.search).get("t");
|
||||
if (t !== null) { tl.pause(); tl.seek(parseFloat(t)); } // frozen at t seconds
|
||||
// no ?t → plays normally
|
||||
window.__ready = true; // ready signal for headless wait
|
||||
console.log("duration", tl.duration());
|
||||
</script>
|
||||
```
|
||||
|
||||
**Verify loop — render → freeze → screenshot → check:**
|
||||
1. Open the file at three moments across the timeline — start, mid, end:
|
||||
`…/anim.html?t=0`, `?t=<dur/2>`, `?t=<dur>`. Read `tl.duration()` from the console for the end time.
|
||||
2. Screenshot each frozen frame.
|
||||
3. Check both **fidelity** (does it match the brief?) and **artifacts** (clipped text, elements off-canvas, FOUC before fonts load, jank at seams). Output should look intentional and finished.
|
||||
|
||||
Any headless screenshot tool works — your agent's browser tool, or Playwright:
|
||||
|
||||
```bash
|
||||
npx playwright screenshot --wait-for-timeout=500 "file://$PWD/anim.html?t=1.2" frame-mid.png
|
||||
```
|
||||
|
||||
**Before you finish:**
|
||||
1. Opens standalone in a browser — no console errors, no missing CDN.
|
||||
2. All animation on one master timeline; `?t=N` freezes correctly.
|
||||
3. Screenshotted at start / mid / end — matches the brief, no artifacts.
|
||||
4. `prefers-reduced-motion` honored (timeline simplified or skipped).
|
||||
5. Easing is intentional — no accidental `linear` on spatial motion.
|
||||
|
||||
A complete runnable template with the harness wired in is in `examples/standalone-template.html`.
|
||||
|
||||
## Quick reference
|
||||
|
||||
| Goal | API |
|
||||
|------|-----|
|
||||
| Sequence with overlap | `tl.from(...).from(..., "-=0.3")` |
|
||||
| Pin while scrolling | `scrollTrigger:{ pin:true, end:"+=N" }` |
|
||||
| Scrub to scroll | `scrollTrigger:{ scrub:1, ease:"none" }` |
|
||||
| Reveal lines of text | `SplitText.create(el,{type:"lines"})` |
|
||||
| Animate layout change | `Flip.getState` → mutate → `Flip.from` |
|
||||
| Fast pointer follow | `gsap.quickTo(el,"x",{...})` |
|
||||
| Kill everything | `ScrollTrigger.getAll().forEach(t=>t.kill())` |
|
||||
|
||||
## Reference files
|
||||
|
||||
- `references/scrolltrigger-cookbook.md` — pin, scrub, horizontal scroll, snap, `ScrollTrigger.batch()` reveals, parallax, nested triggers, and SPA cleanup patterns with full code.
|
||||
- `references/scrolltrigger-lenis.md` — full ScrollTrigger + Lenis/Locomotive smooth-scroll sync: canonical wiring, `scrollerProxy`, anchor links, reduced-motion, React (`useGSAP`/`useEffect`), debugging checklist, and symptom→cause table.
|
||||
- `examples/hero-timeline.js` — a complete, runnable hero entrance timeline with SplitText, staggered reveals, and reduced-motion handling.
|
||||
- `examples/standalone-template.html` — the deliverable template: self-contained (CDN GSAP), one master timeline, the `?t=N` seek harness for screenshot verification, and reduced-motion handling.
|
||||
@@ -1,67 +0,0 @@
|
||||
/**
|
||||
* hero-timeline.js — complete, runnable GSAP hero entrance.
|
||||
*
|
||||
* Markup expected:
|
||||
* <section class="hero">
|
||||
* <p class="hero__eyebrow">EYEBROW</p>
|
||||
* <h1 class="hero__title">Big bold headline that wraps</h1>
|
||||
* <p class="hero__sub">Supporting copy.</p>
|
||||
* <div class="hero__actions"><a class="btn">Primary</a><a class="btn btn--ghost">Secondary</a></div>
|
||||
* <img class="hero__art" src="art.svg" alt="" />
|
||||
* </section>
|
||||
*
|
||||
* CSS prerequisite: each split line wrapper needs overflow:hidden for the mask reveal:
|
||||
* .hero__title .line { overflow: hidden; }
|
||||
*
|
||||
* Install: npm i gsap @gsap/react
|
||||
*/
|
||||
|
||||
import gsap from "gsap";
|
||||
import { SplitText } from "gsap/SplitText";
|
||||
|
||||
gsap.registerPlugin(SplitText);
|
||||
|
||||
export function playHeroIntro(root = document) {
|
||||
const reduceMotion = window.matchMedia("(prefers-reduced-motion: reduce)").matches;
|
||||
const q = gsap.utils.selector(root);
|
||||
|
||||
// Reduced motion: reveal everything instantly, no animation.
|
||||
if (reduceMotion) {
|
||||
gsap.set(q(".hero__eyebrow, .hero__sub, .hero__actions, .hero__art"), { autoAlpha: 1 });
|
||||
gsap.set(q(".hero__title"), { autoAlpha: 1 });
|
||||
return Promise.resolve();
|
||||
}
|
||||
|
||||
// Wait for fonts so SplitText computes correct line breaks.
|
||||
return document.fonts.ready.then(() => {
|
||||
const titleEl = q(".hero__title")[0];
|
||||
const split = new SplitText(titleEl, {
|
||||
type: "lines",
|
||||
linesClass: "line",
|
||||
autoSplit: true, // GSAP 3.13+: re-split on resize/font swap
|
||||
});
|
||||
|
||||
// Hidden start state (prevents flash of unstyled content).
|
||||
gsap.set(q(".hero__eyebrow, .hero__sub, .hero__actions, .hero__art"), { autoAlpha: 0 });
|
||||
gsap.set(titleEl, { autoAlpha: 1 });
|
||||
|
||||
const tl = gsap.timeline({
|
||||
defaults: { ease: "power3.out", duration: 0.8 },
|
||||
onComplete: () => split.revert(), // restore clean DOM once done (optional)
|
||||
});
|
||||
|
||||
tl.from(".hero__eyebrow", { y: 16, autoAlpha: 0, duration: 0.5 })
|
||||
.from(split.lines, { yPercent: 110, stagger: 0.12, duration: 0.9, ease: "power4.out" }, "-=0.2")
|
||||
.from(".hero__sub", { y: 20, autoAlpha: 0 }, "-=0.6")
|
||||
.from(".hero__actions .btn", { y: 12, autoAlpha: 0, stagger: 0.1, duration: 0.5 }, "-=0.4")
|
||||
.from(".hero__art", { scale: 0.92, autoAlpha: 0, ease: "back.out(1.4)", duration: 1.1 }, "<0.1");
|
||||
|
||||
return tl;
|
||||
});
|
||||
}
|
||||
|
||||
// Auto-run on DOM ready when imported directly in a page.
|
||||
if (typeof window !== "undefined" && document.querySelector(".hero")) {
|
||||
if (document.readyState !== "loading") playHeroIntro();
|
||||
else document.addEventListener("DOMContentLoaded", () => playHeroIntro());
|
||||
}
|
||||
@@ -1,59 +0,0 @@
|
||||
<!doctype html>
|
||||
<html lang="en">
|
||||
<head>
|
||||
<meta charset="utf-8" />
|
||||
<meta name="viewport" content="width=device-width, initial-scale=1" />
|
||||
<title>loading</title>
|
||||
<!-- GSAP core from CDN — no build step. Add plugins the same way if needed:
|
||||
https://cdnjs.cloudflare.com/ajax/libs/gsap/3.13.0/ScrollTrigger.min.js -->
|
||||
<script src="https://cdnjs.cloudflare.com/ajax/libs/gsap/3.13.0/gsap.min.js"></script>
|
||||
<style>
|
||||
:root { color-scheme: dark; }
|
||||
* { margin: 0; box-sizing: border-box; }
|
||||
body {
|
||||
min-height: 100svh; display: grid; place-items: center;
|
||||
background: radial-gradient(120% 120% at 50% 0%, #1b1f3b 0%, #0a0a12 60%);
|
||||
font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
|
||||
color: #f4f5ff; overflow: hidden;
|
||||
}
|
||||
.stage { text-align: center; padding: 6vmin; }
|
||||
.title { font-size: clamp(2.5rem, 9vw, 6rem); font-weight: 800; letter-spacing: -0.03em; line-height: 1; }
|
||||
.sub { font-size: clamp(1rem, 3.2vw, 1.6rem); margin-top: 1.2rem; color: #aab; }
|
||||
.cta { display: inline-block; margin-top: 2.4rem; padding: 0.9rem 1.8rem;
|
||||
border-radius: 999px; background: #5b6cff; color: #fff; font-weight: 600; }
|
||||
</style>
|
||||
</head>
|
||||
<body>
|
||||
<main class="stage">
|
||||
<h1 class="title">Ship it.</h1>
|
||||
<p class="sub">A standalone, screenshot-verifiable GSAP scene.</p>
|
||||
<a class="cta" href="#">Get started</a>
|
||||
</main>
|
||||
|
||||
<script>
|
||||
const reduce = matchMedia("(prefers-reduced-motion: reduce)").matches;
|
||||
|
||||
// ── One master timeline: a single playhead the harness can seek ──────────
|
||||
const tl = gsap.timeline({ defaults: { ease: "power3.out", duration: 0.7 } });
|
||||
|
||||
if (reduce) {
|
||||
// Reduced motion: no spatial movement — just make the final state visible.
|
||||
gsap.set([".title", ".sub", ".cta"], { opacity: 1, y: 0 });
|
||||
} else {
|
||||
tl.from(".title", { yPercent: 110, opacity: 0, ease: "power4.out", duration: 0.9 })
|
||||
.from(".sub", { y: 24, opacity: 0 }, "-=0.45")
|
||||
.from(".cta", { scale: 0.9, opacity: 0, ease: "back.out(1.7)" }, "-=0.3");
|
||||
}
|
||||
|
||||
// ── Seek harness: ?t=N freezes the timeline at N seconds for a clean shot ─
|
||||
const t = new URLSearchParams(location.search).get("t");
|
||||
if (t !== null) { tl.pause(); tl.seek(parseFloat(t)); } // deterministic frozen frame
|
||||
// no ?t → plays normally on load
|
||||
|
||||
// ── Ready signals for headless verification ──────────────────────────────
|
||||
window.__ready = true;
|
||||
document.title = "ready";
|
||||
console.log("duration", tl.duration()); // end time for the ?t=<dur> shot
|
||||
</script>
|
||||
</body>
|
||||
</html>
|
||||
@@ -1,181 +0,0 @@
|
||||
# ScrollTrigger Cookbook
|
||||
|
||||
Runnable patterns for GSAP 3.12+. Register first:
|
||||
|
||||
```js
|
||||
import gsap from "gsap";
|
||||
import { ScrollTrigger } from "gsap/ScrollTrigger";
|
||||
gsap.registerPlugin(ScrollTrigger);
|
||||
```
|
||||
|
||||
## 1. Pin a section and scrub a timeline through it
|
||||
|
||||
The most common scrollytelling pattern: hold a section fixed and drive a multi-step timeline with scroll.
|
||||
|
||||
```js
|
||||
const tl = gsap.timeline({
|
||||
scrollTrigger: {
|
||||
trigger: ".story",
|
||||
start: "top top",
|
||||
end: "+=3000", // total scroll distance the pin lasts
|
||||
pin: true,
|
||||
scrub: 1,
|
||||
anticipatePin: 1, // reduces a 1-frame jump when pinning fast scroll
|
||||
},
|
||||
});
|
||||
|
||||
tl.from(".story .step-1", { autoAlpha: 0, y: 60 })
|
||||
.from(".story .step-2", { autoAlpha: 0, y: 60 })
|
||||
.to(".story .bg", { scale: 1.2, ease: "none" }, 0); // runs across whole timeline
|
||||
```
|
||||
|
||||
Tips:
|
||||
- Each tween occupies an equal slice of the pinned distance unless you set durations/positions.
|
||||
- `pinSpacing: true` (default) adds padding so content below does not jump. Set `false` only when overlaying.
|
||||
- If the pinned element is inside a transformed/`overflow` ancestor, pinning breaks — pin a top-level element or set `pinReparent: true`.
|
||||
|
||||
## 2. Horizontal scroll (panels move sideways as the page scrolls vertically)
|
||||
|
||||
```html
|
||||
<section class="h-wrap"><div class="track">
|
||||
<div class="panel">1</div><div class="panel">2</div><div class="panel">3</div>
|
||||
</div></section>
|
||||
```
|
||||
|
||||
```css
|
||||
.track { display: flex; width: max-content; }
|
||||
.panel { width: 100vw; height: 100vh; flex: 0 0 100vw; }
|
||||
```
|
||||
|
||||
```js
|
||||
const track = document.querySelector(".track");
|
||||
gsap.to(track, {
|
||||
x: () => -(track.scrollWidth - window.innerWidth), // function = recalculated on refresh
|
||||
ease: "none",
|
||||
scrollTrigger: {
|
||||
trigger: ".h-wrap",
|
||||
pin: true,
|
||||
scrub: 1,
|
||||
end: () => "+=" + (track.scrollWidth - window.innerWidth),
|
||||
invalidateOnRefresh: true, // re-run the x function on resize
|
||||
},
|
||||
});
|
||||
```
|
||||
|
||||
`invalidateOnRefresh: true` plus function-based values is the correct way to stay responsive.
|
||||
|
||||
## 3. Snap to sections
|
||||
|
||||
```js
|
||||
gsap.to(".sections", {
|
||||
scrollTrigger: {
|
||||
trigger: ".sections",
|
||||
pin: true,
|
||||
scrub: 1,
|
||||
end: "+=4000",
|
||||
snap: {
|
||||
snapTo: 1 / 4, // 5 evenly spaced points (labels also possible: "labels")
|
||||
duration: { min: 0.2, max: 0.6 },
|
||||
delay: 0.05,
|
||||
ease: "power1.inOut",
|
||||
},
|
||||
},
|
||||
});
|
||||
```
|
||||
|
||||
To snap to timeline labels: build a labeled timeline and use `snap: "labelsDirectional"`.
|
||||
|
||||
## 4. Batch reveals (performant many-element fade-in)
|
||||
|
||||
Instead of creating one ScrollTrigger per card (expensive at scale), batch them:
|
||||
|
||||
```js
|
||||
ScrollTrigger.batch(".card", {
|
||||
start: "top 85%",
|
||||
onEnter: (els) =>
|
||||
gsap.from(els, { autoAlpha: 0, y: 40, stagger: 0.12, overwrite: true }),
|
||||
onLeaveBack: (els) =>
|
||||
gsap.to(els, { autoAlpha: 0, y: 40, stagger: 0.12, overwrite: true }),
|
||||
});
|
||||
```
|
||||
|
||||
Set the initial hidden state to avoid a flash before JS runs: `gsap.set(".card", { autoAlpha: 0 })`.
|
||||
|
||||
## 5. Parallax layers
|
||||
|
||||
```js
|
||||
gsap.utils.toArray(".parallax").forEach((layer) => {
|
||||
const depth = layer.dataset.depth || 0.3; // 0 = static, 1 = scrolls with page
|
||||
gsap.to(layer, {
|
||||
yPercent: -depth * 100,
|
||||
ease: "none",
|
||||
scrollTrigger: { trigger: layer.parentElement, scrub: true, start: "top bottom", end: "bottom top" },
|
||||
});
|
||||
});
|
||||
```
|
||||
|
||||
## 6. Linked timelines / containerAnimation (triggers inside horizontal scroll)
|
||||
|
||||
To trigger animations off elements that move horizontally inside a pinned horizontal scroller, pass the horizontal tween as `containerAnimation`:
|
||||
|
||||
```js
|
||||
const scrollTween = gsap.to(track, { x: -2000, ease: "none",
|
||||
scrollTrigger: { trigger: ".h-wrap", pin: true, scrub: 1, end: "+=2000" } });
|
||||
|
||||
gsap.from(".panel-2 .title", {
|
||||
autoAlpha: 0, y: 50,
|
||||
scrollTrigger: { trigger: ".panel-2 .title", containerAnimation: scrollTween, start: "left center" },
|
||||
});
|
||||
```
|
||||
|
||||
Note `start: "left center"` uses horizontal keywords because the trigger moves horizontally.
|
||||
|
||||
## 7. Refresh on dynamic content
|
||||
|
||||
Images and lazy content change layout after triggers are computed. Refresh when ready:
|
||||
|
||||
```js
|
||||
window.addEventListener("load", () => ScrollTrigger.refresh());
|
||||
imagesLoaded(document.body, () => ScrollTrigger.refresh()); // if using imagesLoaded lib
|
||||
```
|
||||
|
||||
For accordions/tabs that change height, call `ScrollTrigger.refresh()` after the layout settles.
|
||||
|
||||
## 8. SPA / React cleanup (critical)
|
||||
|
||||
Orphaned ScrollTriggers cause ghost pins, leaks, and stacking bugs on route changes. Always scope and revert.
|
||||
|
||||
React with `@gsap/react`:
|
||||
|
||||
```jsx
|
||||
import { useGSAP } from "@gsap/react";
|
||||
|
||||
function Section() {
|
||||
const root = useRef(null);
|
||||
useGSAP(() => {
|
||||
gsap.from(".item", {
|
||||
autoAlpha: 0, y: 40, stagger: 0.1,
|
||||
scrollTrigger: { trigger: ".item", start: "top 80%" },
|
||||
});
|
||||
}, { scope: root }); // auto-reverts on unmount
|
||||
return <div ref={root}>...</div>;
|
||||
}
|
||||
```
|
||||
|
||||
Plain SPA / manual:
|
||||
|
||||
```js
|
||||
const ctx = gsap.context(() => { /* all gsap code */ }, rootEl);
|
||||
// on teardown / route leave:
|
||||
ctx.revert();
|
||||
```
|
||||
|
||||
Nuclear option (e.g. global router hook): `ScrollTrigger.getAll().forEach((t) => t.kill());`
|
||||
|
||||
## Debugging checklist
|
||||
|
||||
- Triggers fire at wrong scroll position → likely created before images loaded; call `ScrollTrigger.refresh()`.
|
||||
- Pinned element jumps to top-left → it has a transformed/`will-change`/`overflow:hidden` ancestor; pin higher up.
|
||||
- Animation plays once then never resets → set appropriate `toggleActions` or use `scrub`.
|
||||
- Horizontal scroll not responsive → use function-based `x`/`end` + `invalidateOnRefresh: true`.
|
||||
- Markers misaligned → leftover triggers from previous render; ensure cleanup runs.
|
||||
@@ -1,255 +0,0 @@
|
||||
# ScrollTrigger + Lenis / Locomotive smooth-scroll sync
|
||||
|
||||
Wire GSAP ScrollTrigger together with Lenis (or Locomotive) smooth scrolling so there is no jitter, no marker drift, no broken pins, and no flipped/laggy scroll direction. Every one of those bugs has the same root cause: two animation loops running independently. Lenis transforms the scroll position on its own `requestAnimationFrame` loop while ScrollTrigger reads scroll on GSAP's ticker — when they tick separately, ScrollTrigger samples a stale position and everything desyncs. The fix is to run one loop: let GSAP's ticker drive Lenis, and tell ScrollTrigger to update on every Lenis scroll.
|
||||
|
||||
## The one canonical wiring (Lenis)
|
||||
|
||||
This is the entire correct setup. Do not add a separate `requestAnimationFrame` loop for Lenis — that is the most common mistake and the source of nearly all desync.
|
||||
|
||||
```js
|
||||
import Lenis from 'lenis';
|
||||
import gsap from 'gsap';
|
||||
import { ScrollTrigger } from 'gsap/ScrollTrigger';
|
||||
|
||||
gsap.registerPlugin(ScrollTrigger);
|
||||
|
||||
const lenis = new Lenis({
|
||||
duration: 1.2,
|
||||
smoothWheel: true,
|
||||
// do NOT enable Lenis's own rAF; GSAP's ticker drives it (below)
|
||||
});
|
||||
|
||||
// 1. Update ScrollTrigger every time Lenis scrolls
|
||||
lenis.on('scroll', ScrollTrigger.update);
|
||||
|
||||
// 2. Drive Lenis from GSAP's ticker (single shared loop).
|
||||
// gsap.ticker time is in SECONDS; Lenis expects MILLISECONDS.
|
||||
gsap.ticker.add((time) => {
|
||||
lenis.raf(time * 1000);
|
||||
});
|
||||
|
||||
// 3. Disable GSAP's lag smoothing so ScrollTrigger never defers/
|
||||
// catches up against Lenis (prevents jitter on heavy frames)
|
||||
gsap.ticker.lagSmoothing(0);
|
||||
```
|
||||
|
||||
Three lines do all the work:
|
||||
|
||||
1. `lenis.on('scroll', ScrollTrigger.update)` — ScrollTrigger recomputes positions the instant Lenis moves the page, so triggers/markers/pins track the smoothed scroll exactly.
|
||||
2. `gsap.ticker.add(time => lenis.raf(time * 1000))` — Lenis advances inside GSAP's loop, guaranteeing both run on the same frame and in the same order. Critical unit conversion: `gsap.ticker` passes seconds, `lenis.raf()` wants milliseconds, so multiply by 1000.
|
||||
3. `gsap.ticker.lagSmoothing(0)` — disables GSAP's catch-up behavior that, combined with Lenis, causes visible jitter when a frame is slow.
|
||||
|
||||
After this, never call `requestAnimationFrame(raf)` for Lenis yourself. If any tutorial code has a standalone `function raf(time){ lenis.raf(time); requestAnimationFrame(raf) }` loop, delete it — it competes with the ticker and reintroduces jitter and direction lag.
|
||||
|
||||
## Locomotive Scroll variant
|
||||
|
||||
Locomotive needs `scrollerProxy` because it scrolls an inner element, not `window`. The principle is identical (one loop, update ScrollTrigger on scroll), but the proxy maps coordinates:
|
||||
|
||||
```js
|
||||
const locoScroll = new LocomotiveScroll({
|
||||
el: document.querySelector('[data-scroll-container]'),
|
||||
smooth: true,
|
||||
});
|
||||
|
||||
locoScroll.on('scroll', ScrollTrigger.update);
|
||||
|
||||
ScrollTrigger.scrollerProxy('[data-scroll-container]', {
|
||||
scrollTop(value) {
|
||||
return arguments.length
|
||||
? locoScroll.scrollTo(value, { duration: 0, disableLerp: true })
|
||||
: locoScroll.scroll.instance.scroll.y;
|
||||
},
|
||||
getBoundingClientRect() {
|
||||
return { top: 0, left: 0, width: innerWidth, height: innerHeight };
|
||||
},
|
||||
pinType: document.querySelector('[data-scroll-container]').style.transform
|
||||
? 'transform' : 'fixed',
|
||||
});
|
||||
|
||||
ScrollTrigger.addEventListener('refresh', () => locoScroll.update());
|
||||
ScrollTrigger.refresh();
|
||||
```
|
||||
|
||||
Every ScrollTrigger then needs `scroller: '[data-scroll-container]'`. Lenis is simpler because it scrolls the real document, so no `scrollerProxy` is needed.
|
||||
|
||||
## Pins, refresh, and resize
|
||||
|
||||
- Pinned ScrollTriggers work without `scrollerProxy` under Lenis because Lenis scrolls the document body. If pins still jump, ensure no rogue rAF loop exists and that `ScrollTrigger.update` is wired.
|
||||
- On dynamic content/resize, call `ScrollTrigger.refresh()` after layout settles. With Lenis, also call `lenis.resize()` if container size changes.
|
||||
- For elements that should *not* be smoothed (e.g. a modal that scrolls natively), mark with `data-lenis-prevent` so Lenis ignores them.
|
||||
|
||||
## Anchor links with smooth scroll
|
||||
|
||||
Native `<a href="#section">` jumps bypass Lenis (instant jump, then Lenis fights it). Route anchors through `lenis.scrollTo`:
|
||||
|
||||
```js
|
||||
document.querySelectorAll('a[href^="#"]').forEach((a) => {
|
||||
a.addEventListener('click', (e) => {
|
||||
const id = a.getAttribute('href');
|
||||
if (id.length > 1) {
|
||||
e.preventDefault();
|
||||
lenis.scrollTo(id, { offset: 0 }); // accepts selector, element, or number
|
||||
}
|
||||
});
|
||||
});
|
||||
```
|
||||
|
||||
If a sticky header overlaps the target, pass a negative offset or an offset callback:
|
||||
|
||||
```js
|
||||
lenis.scrollTo(targetEl, { offset: -80 }); // 80px sticky header
|
||||
```
|
||||
|
||||
## Reduced-motion gate
|
||||
|
||||
Respect `prefers-reduced-motion`: skip smooth scrolling entirely (do not instantiate Lenis, or stop it) and let ScrollTrigger run on native scroll.
|
||||
|
||||
```js
|
||||
const prefersReduced = matchMedia('(prefers-reduced-motion: reduce)').matches;
|
||||
|
||||
let lenis;
|
||||
if (!prefersReduced) {
|
||||
lenis = new Lenis({ duration: 1.2 });
|
||||
lenis.on('scroll', ScrollTrigger.update);
|
||||
gsap.ticker.add((time) => lenis.raf(time * 1000));
|
||||
gsap.ticker.lagSmoothing(0);
|
||||
}
|
||||
// ScrollTrigger animations are defined normally and work with or without Lenis
|
||||
```
|
||||
|
||||
## Cleanup (SPA / React / route changes)
|
||||
|
||||
Destroy Lenis and remove the ticker callback on unmount, or stacked loops accumulate:
|
||||
|
||||
```js
|
||||
function setup() {
|
||||
const update = (time) => lenis.raf(time * 1000);
|
||||
lenis.on('scroll', ScrollTrigger.update);
|
||||
gsap.ticker.add(update);
|
||||
gsap.ticker.lagSmoothing(0);
|
||||
return () => {
|
||||
gsap.ticker.remove(update);
|
||||
lenis.destroy();
|
||||
ScrollTrigger.getAll().forEach((t) => t.kill());
|
||||
};
|
||||
}
|
||||
```
|
||||
|
||||
## Debugging checklist (work top to bottom)
|
||||
|
||||
1. **Is there a rogue rAF loop?** Search the codebase for `requestAnimationFrame` near `lenis.raf`. If Lenis is also driven by `gsap.ticker`, delete the standalone loop. Two loops = jitter, lag, flipped feel.
|
||||
2. **Unit conversion present?** Confirm `lenis.raf(time * 1000)` inside the ticker. Missing `* 1000` makes scroll feel stuck or wildly slow.
|
||||
3. **Is `ScrollTrigger.update` subscribed?** `lenis.on('scroll', ScrollTrigger.update)` must exist. Without it, markers and triggers drift behind the smoothed position.
|
||||
4. **Is `lagSmoothing(0)` set?** Without it, heavy frames cause GSAP to "catch up", visible as jitter.
|
||||
5. **Markers on for diagnosis.** Add `markers: true` to a trigger. If markers sit at the *native* scroll position but content moves with smoothed scroll, the update subscription is missing or a proxy is mis-set.
|
||||
6. **Pins jumping?** Confirm no proxy is set for Lenis (it scrolls the document). For Locomotive, confirm `pinType` and `scroller` are correct.
|
||||
7. **After dynamic content / fonts / images load**, call `ScrollTrigger.refresh()`. Stale measurements cause triggers to fire at wrong offsets.
|
||||
8. **Nested scroll areas** (modals, code blocks) misbehave? Add `data-lenis-prevent` to the scrollable child.
|
||||
9. **Cleanup on route change?** In SPAs, verify `gsap.ticker.remove(update)`, `lenis.destroy()`, and killing ScrollTriggers — otherwise each navigation stacks another loop.
|
||||
|
||||
## Symptom → cause table
|
||||
|
||||
| Symptom | Most likely cause |
|
||||
|---|---|
|
||||
| General jitter/stutter | Standalone rAF loop + ticker both driving Lenis |
|
||||
| Scroll stuck / barely moves | Missing `* 1000` unit conversion |
|
||||
| Markers offset from triggers | `ScrollTrigger.update` not bound to `lenis.on('scroll')` |
|
||||
| Jitter only on heavy frames | `lagSmoothing(0)` not set |
|
||||
| Pins jump / break | Proxy wrongly set under Lenis, or wrong `pinType` (Loco) |
|
||||
| Animations a frame behind | Two loops out of order; consolidate to one ticker |
|
||||
| Anchor links jump then snap back | Native `#hash` jump not routed via `lenis.scrollTo` |
|
||||
| Triggers fire at wrong scroll position | Missing `ScrollTrigger.refresh()` after content/layout change |
|
||||
| Worse after each route change | No cleanup; loops/triggers accumulating |
|
||||
| Inner scroll container won't scroll | Lenis intercepting; add `data-lenis-prevent` |
|
||||
|
||||
## Complete React integration (useGSAP)
|
||||
|
||||
```jsx
|
||||
'use client';
|
||||
import { useRef } from 'react';
|
||||
import Lenis from 'lenis';
|
||||
import gsap from 'gsap';
|
||||
import { ScrollTrigger } from 'gsap/ScrollTrigger';
|
||||
import { useGSAP } from '@gsap/react';
|
||||
|
||||
gsap.registerPlugin(ScrollTrigger, useGSAP);
|
||||
|
||||
export default function ScrollSection() {
|
||||
const root = useRef(null);
|
||||
|
||||
useGSAP(() => {
|
||||
const prefersReduced = matchMedia('(prefers-reduced-motion: reduce)').matches;
|
||||
|
||||
let lenis;
|
||||
let update;
|
||||
if (!prefersReduced) {
|
||||
lenis = new Lenis({ duration: 1.2, smoothWheel: true });
|
||||
lenis.on('scroll', ScrollTrigger.update);
|
||||
update = (time) => lenis.raf(time * 1000);
|
||||
gsap.ticker.add(update);
|
||||
gsap.ticker.lagSmoothing(0);
|
||||
}
|
||||
|
||||
gsap.to('.panel', {
|
||||
xPercent: -100,
|
||||
ease: 'none',
|
||||
scrollTrigger: {
|
||||
trigger: '.panel',
|
||||
start: 'top top',
|
||||
end: '+=1500',
|
||||
scrub: true,
|
||||
pin: true,
|
||||
// markers: true, // enable while debugging
|
||||
},
|
||||
});
|
||||
|
||||
return () => {
|
||||
if (lenis) {
|
||||
gsap.ticker.remove(update);
|
||||
lenis.destroy();
|
||||
}
|
||||
};
|
||||
}, { scope: root });
|
||||
|
||||
return (
|
||||
<div ref={root}>
|
||||
<section className="panel">…</section>
|
||||
</div>
|
||||
);
|
||||
}
|
||||
```
|
||||
|
||||
`useGSAP` auto-reverts GSAP tweens/ScrollTriggers created in its scope on unmount; the returned function additionally tears down Lenis and the ticker callback so nothing leaks across navigations.
|
||||
|
||||
## Plain useEffect equivalent
|
||||
|
||||
```jsx
|
||||
useEffect(() => {
|
||||
const lenis = new Lenis({ duration: 1.2 });
|
||||
lenis.on('scroll', ScrollTrigger.update);
|
||||
const update = (t) => lenis.raf(t * 1000);
|
||||
gsap.ticker.add(update);
|
||||
gsap.ticker.lagSmoothing(0);
|
||||
|
||||
const ctx = gsap.context(() => {
|
||||
// ...ScrollTrigger animations here...
|
||||
});
|
||||
|
||||
return () => {
|
||||
gsap.ticker.remove(update);
|
||||
lenis.destroy();
|
||||
ctx.revert();
|
||||
};
|
||||
}, []);
|
||||
```
|
||||
|
||||
## Excluding regions from smooth scroll
|
||||
|
||||
```html
|
||||
<div class="code-block" data-lenis-prevent>…natively scrollable…</div>
|
||||
```
|
||||
|
||||
`data-lenis-prevent` on a scrollable element makes Lenis ignore wheel/touch there, so inner scrolling works normally while the page stays smooth.
|
||||
|
||||
---
|
||||
Sync ScrollTrigger to smooth scroll and the timeline tracks the page perfectly. Built by **[iart.ai](https://iart.ai/?utm_source=github&utm_medium=readme&utm_campaign=web-animation-skills&utm_content=skill_footer&utm_term=gsap-web)** — the AI motion agent for editable, on-brand motion graphics.
|
||||
File renamed without changes.
@@ -0,0 +1,148 @@
|
||||
---
|
||||
name: logo-animation
|
||||
description: This skill should be used when the user asks to "animate our logo", "make a logo intro/stinger", "build a brand reveal", "create an app splash animation", "loop a loader logo", "draw on our SVG mark", "morph an icon into the wordmark", or "sync the logo to a sound-logo". Covers web (SVG/Lottie), video, and app-splash delivery.
|
||||
version: 0.1.0
|
||||
---
|
||||
|
||||
# Logo Animation
|
||||
|
||||
Bring a brand mark to life with one clear idea, on-brand geometry, and a crisp settle. Animate for web (SVG/Lottie), video intros/outros, or app splash screens, and always ship a static end-frame fallback.
|
||||
|
||||
## When to use
|
||||
|
||||
- Build an intro stinger, sign-off, app splash, or loader idle loop.
|
||||
- Reveal a brand mark on a landing hero or sizzle reel.
|
||||
- Draw on an SVG mark, wipe/build it in piece by piece, or morph an icon into a wordmark.
|
||||
- Sync the final settle of the mark to a sound-logo beat.
|
||||
|
||||
## Core principle
|
||||
|
||||
Pick ONE technique per logo — draw OR build OR morph — not all at once. Reveals run 0.8–2.5s. Never distort brand geometry; scale and fade are safe, skew and squash usually are not. Respect clearspace (keep the mark's minimum margin clear of motion debris). Always provide a `prefers-reduced-motion` path that shows the final mark with no motion.
|
||||
|
||||
## Technique map
|
||||
|
||||
| Technique | Best for | Mechanism |
|
||||
|---|---|---|
|
||||
| Stroke draw-on | Line marks, monograms, signatures | `stroke-dashoffset` 1→0 |
|
||||
| Mask wipe / reveal | Filled shapes, gradients | animate a `<clipPath>` / `<mask>` rect |
|
||||
| Build-on (stagger) | Multi-piece marks, grids | per-group opacity+transform, staggered |
|
||||
| Morph | Icon ↔ wordmark, shape→logo | GSAP MorphSVG or matched path interpolation |
|
||||
| Idle loop | Loaders, ambient splash | seamless cyclic transform (rotate/pulse) |
|
||||
| Wordmark | Logotypes | per-letter mask/translate stagger |
|
||||
|
||||
## Quick start: SVG stroke draw-on
|
||||
|
||||
The fastest on-brand web reveal. Each path draws itself, then fills settle in.
|
||||
|
||||
```html
|
||||
<svg viewBox="0 0 200 80" id="logo">
|
||||
<path class="ink" d="M10 60 L40 20 L70 60" fill="none"
|
||||
stroke="#111" stroke-width="6" stroke-linecap="round"
|
||||
pathLength="1" stroke-dasharray="1" stroke-dashoffset="1"/>
|
||||
</svg>
|
||||
<style>
|
||||
@keyframes draw { to { stroke-dashoffset: 0; } }
|
||||
#logo .ink { animation: draw 1.1s cubic-bezier(.65,0,.35,1) forwards; }
|
||||
@media (prefers-reduced-motion: reduce) {
|
||||
#logo .ink { animation: none; stroke-dashoffset: 0; }
|
||||
}
|
||||
</style>
|
||||
```
|
||||
|
||||
`pathLength="1"` normalizes every path to length 1, so one `stroke-dasharray`/`offset` value works regardless of geometry. Stagger multiple strokes with `animation-delay`.
|
||||
|
||||
## Quick start: build-on with stagger (GSAP)
|
||||
|
||||
```js
|
||||
import gsap from "gsap";
|
||||
// each <g class="piece"> is one mark component
|
||||
gsap.from(".piece", {
|
||||
opacity: 0, scale: 0.85, transformOrigin: "50% 50%",
|
||||
duration: 0.5, ease: "back.out(1.6)", stagger: 0.08,
|
||||
onComplete: () => gsap.to("#mark", { scale: 1, duration: 0.2, ease: "power2.out" })
|
||||
});
|
||||
```
|
||||
|
||||
Group order matters: reveal the base/container first, then accents, then the wordmark last so the eye lands on the name.
|
||||
|
||||
## Sound-logo sync
|
||||
|
||||
When audio exists, the brand's final settle frame must land exactly on the sonic accent (the "ding"/whoosh peak). Decide the audio first, find the peak timecode, then time the reveal so the mark snaps to full opacity/scale on that frame. A 1.0s reveal landing a 1.2s mnemonic feels premium; a settle that floats free of the sound feels cheap. Add a tiny overshoot-and-settle (scale 1.04→1.00 over ~0.15s) on the beat for impact.
|
||||
|
||||
## Delivery targets
|
||||
|
||||
- **Web, interactive / hero**: inline SVG + CSS or GSAP. Smallest payload, crisp at any size, scriptable.
|
||||
- **Product / app, designer-made**: Lottie (`.json` exported from After Effects via Bodymovin). Use `lottie-web` or `@lottiefiles/dotlottie-web`; set `loop`, `autoplay`, and a poster fallback frame.
|
||||
- **Video intro/outro**: Remotion (React) or After Effects render to ProRes/H.264. Pre-render at 2x for crispness.
|
||||
|
||||
```js
|
||||
// Lottie delivery with reduced-motion guard
|
||||
import { DotLottie } from "@lottiefiles/dotlottie-web";
|
||||
const reduce = matchMedia("(prefers-reduced-motion: reduce)").matches;
|
||||
const dl = new DotLottie({
|
||||
canvas: document.querySelector("#logo-canvas"),
|
||||
src: "/logo.lottie", autoplay: !reduce, loop: false,
|
||||
});
|
||||
if (reduce) dl.addEventListener("load", () => dl.setFrame(dl.totalFrames - 1));
|
||||
```
|
||||
|
||||
## Output checklist
|
||||
|
||||
- Animated mark in the target format (SVG/Lottie/video).
|
||||
- Static final-frame fallback (SVG or PNG) for reduced-motion and posters.
|
||||
- One clear technique, reveal ≤2.5s, brand geometry intact, clearspace respected.
|
||||
- Sound-logo settle aligned to the audio peak (if audio present).
|
||||
|
||||
## Deliver & verify (standalone HTML)
|
||||
|
||||
> **Packaged helper** (`scripts/`): `scripts/seek-shot.sh anim.html 0 1.5 3` freezes the `?t=N` harness and screenshots each moment; `scripts/contact-sheet.sh sheet.png frame-*.png` tiles them for one-glance review. See `scripts/README.md`.
|
||||
|
||||
Logo animation spans web/SVG/Lottie, video, and app splash. **For web/SVG/Lottie delivery use this standalone-HTML loop; for a video logo sting, render via the remotion-video verify loop instead.**
|
||||
|
||||
For web/SVG/Lottie, ship **one `.html` file that opens directly in a browser** — inline SVG markup plus the reveal (CSS or one CDN GSAP `<script>`), self-contained. One file is the right tier.
|
||||
|
||||
**Output contract:**
|
||||
- One `.html` file: the inline SVG (or Lottie canvas) + the reveal in inline `<style>`/`<script>`.
|
||||
- One animation driver — the CSS `@keyframes` draw/build, or a single GSAP timeline; not both.
|
||||
- Include the freeze harness below, matched to the technique, so any moment can be screenshotted deterministically.
|
||||
|
||||
**Freeze harness — pin a frame for screenshots.** Match the mechanism to the technique:
|
||||
|
||||
```html
|
||||
<script>
|
||||
const t = new URLSearchParams(location.search).get("t");
|
||||
if (t !== null) {
|
||||
const T = parseFloat(t);
|
||||
// CSS stroke-draw / build-on:
|
||||
document.querySelectorAll("#logo *").forEach(el => {
|
||||
el.style.animationDelay = (-T) + "s";
|
||||
el.style.animationPlayState = "paused";
|
||||
});
|
||||
// GSAP timeline instead? → tl.pause(); tl.seek(T);
|
||||
// SMIL <animate>? → const s = document.querySelector("svg"); s.pauseAnimations(); s.setCurrentTime(T);
|
||||
// Lottie? → dl.setFrame(Math.round(T * fps));
|
||||
}
|
||||
window.__ready = true; // ready signal for headless wait
|
||||
</script>
|
||||
```
|
||||
|
||||
**Verify loop — render → freeze → screenshot → check:**
|
||||
1. Open the file frozen at start / mid / end of the reveal (≤2.5s): `…/logo.html?t=0`, `?t=<dur/2>`, `?t=<dur>`.
|
||||
2. Screenshot each frozen frame.
|
||||
3. Check **fidelity** (matches the mark, one clear technique) and **artifacts** — brand geometry undistorted, clearspace clear of motion debris, no half-drawn strokes left at the end frame, the static final frame is the true logo.
|
||||
4. **Iterate:** if any check fails (e.g. a half-drawn stroke at `?t=<dur>` or distorted geometry mid-reveal), fix the stroke-dashoffset/duration/easing, re-render the **same** `?t=N`, and re-screenshot to confirm the fix — loop until every frame is clean.
|
||||
|
||||
```bash
|
||||
npx playwright screenshot --wait-for-timeout=500 "file://$PWD/logo.html?t=1.1" frame-mid.png
|
||||
```
|
||||
|
||||
**Before you finish:**
|
||||
1. Opens standalone in a browser — no console errors, no missing CDN.
|
||||
2. One technique/driver; `?t=N` freezes the exact frame correctly.
|
||||
3. Screenshotted at start / mid / end — geometry intact, clearspace respected, final frame is the clean mark.
|
||||
4. `prefers-reduced-motion` honored (final static mark shown, no motion) + static end-frame fallback shipped.
|
||||
5. Reveal ≤2.5s; if audio present, the settle lands on the sound-logo peak.
|
||||
|
||||
## Reference files
|
||||
|
||||
- `references/logo-patterns.md` — runnable code for every technique: stroke draw-on, mask wipe build-on, GSAP MorphSVG morph, seamless idle loop, Lottie delivery, plus timing tables (0.8–2.5s), brand clearspace rules, and reduced-motion fallbacks.
|
||||
@@ -0,0 +1,199 @@
|
||||
# Logo Animation Patterns — Cookbook
|
||||
|
||||
Self-contained, runnable recipes for every logo technique. Pick ONE per logo.
|
||||
|
||||
## Timing guidance
|
||||
|
||||
| Beat | Duration | Easing |
|
||||
|---|---|---|
|
||||
| Stroke draw-on (per path) | 0.6–1.2s | `cubic-bezier(.65,0,.35,1)` (easeInOutCubic) |
|
||||
| Mask wipe reveal | 0.5–0.9s | `cubic-bezier(.22,1,.36,1)` (easeOutQuint) |
|
||||
| Build-on per piece | 0.4–0.6s, stagger 0.06–0.10s | `back.out(1.5)` |
|
||||
| Morph | 0.6–1.0s | `power2.inOut` |
|
||||
| Final settle / overshoot | 0.12–0.20s | scale 1.04→1.00, `power2.out` |
|
||||
| Full reveal envelope | 0.8–2.5s total | — |
|
||||
| Idle loop cycle | 1.5–4s, infinite | `sine.inOut` / `linear` for spin |
|
||||
|
||||
Rule of thumb: longer marks (wordmarks, detailed monograms) sit near 2.0–2.5s; simple icons near 0.8–1.4s. Hold the settled mark at least 0.4s before any sign-off cut.
|
||||
|
||||
## Brand clearspace & geometry rules
|
||||
|
||||
- **Clearspace**: keep a margin equal to the mark's cap-height (or the brand's defined unit) clear of moving particles, wipes, or overshoot. Motion must not visually crop into the safe margin.
|
||||
- **No distortion**: scale uniformly, fade, translate, rotate-on-axis, and mask are safe. Avoid non-uniform `scaleX≠scaleY`, skew, and squash on the final mark — they read as off-brand. A squash-and-settle is acceptable ONLY as a sub-0.2s micro-overshoot that returns to 1.0.
|
||||
- **Color**: never animate brand color away from spec mid-reveal. Reveal in brand color, or grayscale→brand as an intentional, approved beat.
|
||||
- **Lockup integrity**: animate the symbol and wordmark with a clear hierarchy (symbol leads, wordmark follows) but land both in the exact locked relationship.
|
||||
|
||||
## 1. Stroke draw-on (SVG + CSS)
|
||||
|
||||
```html
|
||||
<svg viewBox="0 0 240 80" id="mark">
|
||||
<path class="ink" pathLength="1" fill="none" stroke="#0A84FF"
|
||||
stroke-width="7" stroke-linecap="round" stroke-linejoin="round"
|
||||
d="M12 64 L48 16 L84 64 M120 16 L120 64 M156 16 H204"/>
|
||||
</svg>
|
||||
<style>
|
||||
#mark .ink {
|
||||
stroke-dasharray: 1; stroke-dashoffset: 1;
|
||||
animation: draw 1.1s cubic-bezier(.65,0,.35,1) forwards;
|
||||
}
|
||||
@keyframes draw { to { stroke-dashoffset: 0; } }
|
||||
@media (prefers-reduced-motion: reduce){
|
||||
#mark .ink { animation: none; stroke-dashoffset: 0; }
|
||||
}
|
||||
</style>
|
||||
```
|
||||
|
||||
Draw-then-fill (line settles into a solid mark):
|
||||
|
||||
```css
|
||||
#mark .ink { fill: transparent; }
|
||||
@keyframes fill { to { fill: #0A84FF; stroke-width: 0; } }
|
||||
#mark .ink { animation: draw 1.1s cubic-bezier(.65,0,.35,1) forwards,
|
||||
fill .3s ease .9s forwards; }
|
||||
```
|
||||
|
||||
GSAP equivalent with per-path stagger via DrawSVGPlugin:
|
||||
|
||||
```js
|
||||
import gsap from "gsap";
|
||||
import { DrawSVGPlugin } from "gsap/DrawSVGPlugin";
|
||||
gsap.registerPlugin(DrawSVGPlugin);
|
||||
gsap.fromTo("#mark .ink",
|
||||
{ drawSVG: "0%" },
|
||||
{ drawSVG: "100%", duration: 1.0, ease: "power2.inOut", stagger: 0.15 });
|
||||
```
|
||||
|
||||
## 2. Mask wipe / build-on (clipPath)
|
||||
|
||||
Reveal a filled mark by sweeping a clip rect across it.
|
||||
|
||||
```html
|
||||
<svg viewBox="0 0 200 80">
|
||||
<defs>
|
||||
<clipPath id="wipe"><rect id="wiper" x="0" y="0" width="0" height="80"/></clipPath>
|
||||
</defs>
|
||||
<g clip-path="url(#wipe)">
|
||||
<!-- the full filled logo art here -->
|
||||
<path d="M10 10 H190 V70 H10 Z" fill="#111"/>
|
||||
</g>
|
||||
</svg>
|
||||
<style>
|
||||
#wiper { animation: wipe .8s cubic-bezier(.22,1,.36,1) forwards; }
|
||||
@keyframes wipe { to { width: 200px; } }
|
||||
@media (prefers-reduced-motion: reduce){ #wiper{ animation:none; width:200px; } }
|
||||
</style>
|
||||
```
|
||||
|
||||
Directional variants: animate `y`/`height` for a top-down build, or use a radial `<clipPath>` with a growing `<circle r>` for an iris reveal.
|
||||
|
||||
## 3. Build-on with stagger (GSAP timeline)
|
||||
|
||||
```js
|
||||
import gsap from "gsap";
|
||||
const tl = gsap.timeline({ defaults: { ease: "back.out(1.6)" } });
|
||||
tl.from("#base", { scale: .8, opacity: 0, transformOrigin: "50% 50%", duration: .5 })
|
||||
.from(".accent", { scale: .7, opacity: 0, transformOrigin: "50% 50%",
|
||||
duration: .45, stagger: 0.08 }, "-=0.2")
|
||||
.from(".word > *", { yPercent: 120, opacity: 0, duration: .4,
|
||||
stagger: 0.04, ease: "power3.out" }, "-=0.15")
|
||||
.to("#mark", { scale: 1.04, duration: .12, ease: "power2.out" })
|
||||
.to("#mark", { scale: 1.0, duration: .14, ease: "power2.inOut" });
|
||||
```
|
||||
|
||||
## 4. Morph (GSAP MorphSVG)
|
||||
|
||||
Morph requires two paths; MorphSVG handles differing point counts.
|
||||
|
||||
```js
|
||||
import gsap from "gsap";
|
||||
import { MorphSVGPlugin } from "gsap/MorphSVGPlugin";
|
||||
gsap.registerPlugin(MorphSVGPlugin);
|
||||
// #shape: a simple start shape (e.g. circle path) -> #logoPath: the brand mark
|
||||
gsap.to("#shape", {
|
||||
duration: .9, ease: "power2.inOut",
|
||||
morphSVG: { shape: "#logoPath", shapeIndex: "auto" }
|
||||
});
|
||||
```
|
||||
|
||||
No-plugin fallback (Flubber for interpolation + requestAnimationFrame):
|
||||
|
||||
```js
|
||||
import { interpolate } from "flubber";
|
||||
const from = "M10,10 ...", to = "M0,0 ...";
|
||||
const lerp = interpolate(from, to, { maxSegmentLength: 2 });
|
||||
const path = document.querySelector("#shape");
|
||||
const dur = 900, t0 = performance.now();
|
||||
(function frame(now){
|
||||
const k = Math.min(1, (now - t0) / dur);
|
||||
const e = k < .5 ? 2*k*k : 1 - Math.pow(-2*k+2, 2)/2; // easeInOutQuad
|
||||
path.setAttribute("d", lerp(e));
|
||||
if (k < 1) requestAnimationFrame(frame);
|
||||
})(t0);
|
||||
```
|
||||
|
||||
## 5. Seamless idle loop (loader)
|
||||
|
||||
Loop must have identical start and end frames — design the cycle so frame 0 == frame N.
|
||||
|
||||
```css
|
||||
#loader { animation: spin 1.4s linear infinite, pulse 2.8s ease-in-out infinite; }
|
||||
@keyframes spin { to { transform: rotate(360deg); } }
|
||||
@keyframes pulse { 0%,100%{ opacity:.85 } 50%{ opacity:1 } }
|
||||
@media (prefers-reduced-motion: reduce){
|
||||
#loader { animation: pulse 2.8s ease-in-out infinite; } /* drop rotation */
|
||||
}
|
||||
```
|
||||
|
||||
GSAP `yoyo` loop for a breathing mark:
|
||||
|
||||
```js
|
||||
gsap.to("#mark", { scale: 1.03, duration: 1.4, ease: "sine.inOut",
|
||||
yoyo: true, repeat: -1 });
|
||||
```
|
||||
|
||||
## 6. Lottie delivery (designer-made)
|
||||
|
||||
Export from After Effects via Bodymovin to `.json`, or compressed `.lottie`.
|
||||
|
||||
```html
|
||||
<canvas id="logo-canvas" width="512" height="512"></canvas>
|
||||
<script type="module">
|
||||
import { DotLottie } from "https://cdn.jsdelivr.net/npm/@lottiefiles/dotlottie-web/+esm";
|
||||
const reduce = matchMedia("(prefers-reduced-motion: reduce)").matches;
|
||||
const dl = new DotLottie({
|
||||
canvas: document.querySelector("#logo-canvas"),
|
||||
src: "/logo.lottie", autoplay: !reduce, loop: false, speed: 1,
|
||||
});
|
||||
// Reduced motion: jump to the final settled frame, no playback.
|
||||
if (reduce) dl.addEventListener("load", () => dl.setFrame(dl.totalFrames - 1));
|
||||
// Sound-logo sync: fire audio when the settle frame is reached.
|
||||
dl.addEventListener("frame", ({ currentFrame }) => {
|
||||
if (currentFrame >= SETTLE_FRAME && !audioFired) { audio.play(); audioFired = true; }
|
||||
});
|
||||
</script>
|
||||
```
|
||||
|
||||
Classic `lottie-web` (SVG renderer, sharpest for vector logos):
|
||||
|
||||
```js
|
||||
import lottie from "lottie-web";
|
||||
const anim = lottie.loadAnimation({
|
||||
container: document.getElementById("logo"),
|
||||
renderer: "svg", loop: false, autoplay: !reduce, path: "/logo.json",
|
||||
});
|
||||
if (reduce) anim.goToAndStop(anim.totalFrames - 1, true);
|
||||
```
|
||||
|
||||
Lottie tips: keep layers/effects Bodymovin-supported (no native blurs/expressions unless baked), name layers cleanly, and request a poster PNG of the final frame from the designer for the static fallback.
|
||||
|
||||
## 7. Reduced-motion fallback (always ship)
|
||||
|
||||
Every delivery must degrade to the static, fully-revealed mark:
|
||||
|
||||
- **CSS/SVG**: `@media (prefers-reduced-motion: reduce)` sets the final state (`stroke-dashoffset:0`, `width:full`, `opacity:1`) with `animation:none`.
|
||||
- **Lottie**: `goToAndStop(totalFrames-1)` / `setFrame(last)`.
|
||||
- **Video**: serve a poster image of the last frame; only autoplay motion when motion is allowed.
|
||||
- **JS gate**: branch on `matchMedia("(prefers-reduced-motion: reduce)").matches` before building any timeline.
|
||||
|
||||
---
|
||||
Match the reveal to the delivery target and a logo lands across web, video, and app. Built by **[iart.ai](https://iart.ai/?utm_source=github&utm_medium=readme&utm_campaign=motion-design-skills&utm_content=skill_footer&utm_term=logo-animation)** — the AI motion agent for editable, on-brand motion graphics.
|
||||
@@ -1,180 +0,0 @@
|
||||
---
|
||||
name: lottie-animation
|
||||
description: This skill should be used when the user asks to "add a Lottie animation", "play a .lottie or .json animation", "integrate a Bodymovin/After Effects animation on web or mobile", "control Lottie playback / segments", "make a scroll-driven Lottie", "recolor a Lottie at runtime", or "export an AE animation to Lottie". Covers dotLottie/lottie-web integration, playback control, interactivity, theming, and the AE export checklist.
|
||||
version: 0.1.0
|
||||
---
|
||||
|
||||
# Lottie Animation
|
||||
|
||||
The bridge from After Effects to product: vector animation shipped as JSON (or zipped `.lottie`), tiny and resolution-independent, played by a runtime on web, iOS, Android, and React Native. This skill covers integrating, controlling, and exporting Lottie.
|
||||
|
||||
## When to use
|
||||
|
||||
- Ship a designer's AE animation to web/iOS/Android/React Native
|
||||
- Looping illustrations, onboarding, empty states, animated icons
|
||||
- Scroll-driven or interaction-driven vector playback (hover, click, cursor)
|
||||
- Runtime theming/recoloring instead of re-exporting per brand
|
||||
|
||||
## Formats: .json vs .lottie
|
||||
|
||||
- `.json` — the raw Bodymovin output. Human-readable, larger.
|
||||
- `.lottie` — a zipped container (often 60–80% smaller) that can bundle multiple animations, images, and theming. Preferred for shipping. Player: `@lottiefiles/dotlottie-web` (modern, canvas + WASM) supersedes the older `lottie-web`.
|
||||
|
||||
Prefer the **dotLottie** runtime for new work; use `lottie-web` only for legacy `.json` + SVG renderer needs.
|
||||
|
||||
## Core workflow (web, dotLottie)
|
||||
|
||||
```bash
|
||||
npm i @lottiefiles/dotlottie-web # vanilla
|
||||
npm i @lottiefiles/dotlottie-react # React wrapper
|
||||
```
|
||||
|
||||
Vanilla:
|
||||
|
||||
```js
|
||||
import { DotLottie } from "@lottiefiles/dotlottie-web";
|
||||
|
||||
const dotLottie = new DotLottie({
|
||||
canvas: document.querySelector("#lottie"), // a <canvas> element
|
||||
src: "/hero.lottie", // or .json
|
||||
loop: true,
|
||||
autoplay: true,
|
||||
// speed: 1, mode: "forward" | "reverse" | "bounce", renderConfig: { autoResize: true }
|
||||
});
|
||||
```
|
||||
|
||||
React:
|
||||
|
||||
```jsx
|
||||
import { DotLottieReact } from "@lottiefiles/dotlottie-react";
|
||||
|
||||
function Hero() {
|
||||
return <DotLottieReact src="/hero.lottie" loop autoplay style={{ width: 320 }} />;
|
||||
}
|
||||
```
|
||||
|
||||
Capture the instance to control it:
|
||||
|
||||
```jsx
|
||||
const [dl, setDl] = useState(null);
|
||||
<DotLottieReact src="/icon.lottie" dotLottieRefCallback={setDl} />;
|
||||
// dl?.play(); dl?.pause(); dl?.setSpeed(2);
|
||||
```
|
||||
|
||||
## Playback control
|
||||
|
||||
```js
|
||||
dotLottie.play();
|
||||
dotLottie.pause();
|
||||
dotLottie.stop();
|
||||
dotLottie.setSpeed(1.5);
|
||||
dotLottie.setMode("bounce"); // forward | reverse | bounce | reverse-bounce
|
||||
dotLottie.setFrame(42); // jump to a frame
|
||||
dotLottie.setSegment(30, 90); // constrain playback to a frame range (e.g. a "loading" loop)
|
||||
```
|
||||
|
||||
Events drive sequencing and UI:
|
||||
|
||||
```js
|
||||
dotLottie.addEventListener("load", () => { /* totalFrames now available */ });
|
||||
dotLottie.addEventListener("complete", () => { /* non-looping playback finished */ });
|
||||
dotLottie.addEventListener("frame", ({ currentFrame }) => { /* per-frame */ });
|
||||
```
|
||||
|
||||
State-machine style (e.g. button that plays "checked" segment then idles): play a segment, listen for `complete`, then `setSegment` to the idle loop.
|
||||
|
||||
## Scroll-driven Lottie (no GSAP needed)
|
||||
|
||||
Map scroll progress (0–1) to a frame. Pause autoplay and drive frames yourself.
|
||||
|
||||
```js
|
||||
const dotLottie = new DotLottie({ canvas, src: "/scroll.lottie", autoplay: false });
|
||||
let total = 0;
|
||||
dotLottie.addEventListener("load", () => { total = dotLottie.totalFrames; });
|
||||
|
||||
window.addEventListener("scroll", () => {
|
||||
const el = canvas.closest(".scrolly");
|
||||
const rect = el.getBoundingClientRect();
|
||||
const p = clamp(-rect.top / (rect.height - window.innerHeight), 0, 1); // 0..1 through the section
|
||||
dotLottie.setFrame(p * (total - 1));
|
||||
}, { passive: true });
|
||||
|
||||
const clamp = (v, lo, hi) => Math.min(hi, Math.max(lo, v));
|
||||
```
|
||||
|
||||
For richer interaction (hover-to-play, click toggles, cursor-follow) without writing the wiring, use `@lottiefiles/lottie-interactivity`, which maps `scroll`, `hover`, `click`, `play`, and `cursor` modes to frame ranges declaratively.
|
||||
|
||||
## Runtime theming / recoloring
|
||||
|
||||
Two paths:
|
||||
- **dotLottie themes**: a `.lottie` can embed named color themes; switch with `dotLottie.setTheme("dark")` / `loadTheme(...)`. Authored in LottieFiles tooling — no re-export to recolor.
|
||||
- **Manual color override**: load the JSON, walk `layers[].shapes[]` and patch `c.k` color arrays (normalized 0–1 RGBA), then init the player with the modified object. Brittle (depends on layer structure) — prefer themes or CSS-driven SVG-renderer (`lottie-web` `rendererSettings`) when you must restyle by class.
|
||||
|
||||
## Mobile runtimes (parity)
|
||||
|
||||
- iOS — `lottie-ios` (`LottieAnimationView`): `.play()`, `.currentProgress`, `.play(fromFrame:toFrame:)`.
|
||||
- Android — `lottie-android` (`LottieAnimationView` / Compose `LottieAnimation`): `setMinAndMaxFrame`, `progress`.
|
||||
- React Native — `lottie-react-native` (`<LottieView source={...} progress={anim} />`, drive `progress` with `Animated`).
|
||||
|
||||
The same `.lottie`/`.json` plays across all; segments and progress concepts match the web API.
|
||||
|
||||
## Optimization
|
||||
|
||||
- Ship `.lottie` (zipped) over raw `.json`; lazy-load offscreen players and pause when not visible (`IntersectionObserver` → `play`/`pause`).
|
||||
- Prefer the canvas/WASM dotLottie renderer for many simultaneous animations; SVG renderer (lottie-web) is fine for one crisp icon but costs more DOM for complex files.
|
||||
- Keep AE comps small: fewer layers/keyframes, no large embedded rasters; flatten precomps where possible. File size tracks keyframe and path complexity, not duration.
|
||||
- Recolor at runtime (themes) instead of exporting a file per brand/theme.
|
||||
|
||||
## Deliver & verify (standalone HTML)
|
||||
|
||||
> **Packaged helper** (`scripts/`): `scripts/seek-shot.sh anim.html 0 1.5 3` freezes the `?t=N` harness and screenshots each moment; `scripts/contact-sheet.sh sheet.png frame-*.png` tiles them for one-glance review. See `scripts/README.md`.
|
||||
|
||||
For a self-contained Lottie demo (looping illustration, animated icon, empty state) the deliverable is **one HTML file that opens directly in a browser** — the dotLottie/lottie-web runtime from CDN, a `<canvas>`, and your `.lottie`/`.json` (a relative file or a data URL). No build step. One file is the right tier for shipping a player; don't reach for a bundler.
|
||||
|
||||
**Output contract:**
|
||||
- One `.html` file: the runtime via CDN (`@lottiefiles/dotlottie-web`), the canvas, and `autoplay:false` so the frame is yours to drive.
|
||||
- Include the seek harness so any frame can be frozen for a screenshot.
|
||||
|
||||
**Seek harness — freeze an exact frame.** `?t=N` jumps to a frame and holds it so a screenshot lands on a still, deterministic frame. Lottie's playhead is in frames, so stop on the frame directly:
|
||||
|
||||
```html
|
||||
<script>
|
||||
const dl = new DotLottie({ canvas, src: "/icon.lottie", autoplay: false });
|
||||
dl.addEventListener("load", () => {
|
||||
const t = new URLSearchParams(location.search).get("t");
|
||||
if (t !== null) dl.setFrame(parseFloat(t)); // freeze on frame N (lottie-web: anim.goToAndStop(N, true))
|
||||
else dl.play();
|
||||
console.log("totalFrames", dl.totalFrames); // read for end-frame
|
||||
window.__ready = true;
|
||||
});
|
||||
</script>
|
||||
```
|
||||
|
||||
**Verify loop — render → freeze → screenshot → check:** open the file at first / mid / last frame (`?t=0`, `?t=<total/2>`, `?t=<total-1>`; read `totalFrames` from the console), screenshot each, and check **fidelity** (colors/theme correct, segment loops where intended) plus **artifacts** (canvas blurry from missing `autoResize`/DPR, clipped composition, FOUC before the file loads, jank). Any headless tool works:
|
||||
|
||||
```bash
|
||||
npx playwright screenshot --wait-for-timeout=600 "file://$PWD/lottie.html?t=42" frame-mid.png
|
||||
```
|
||||
|
||||
**Before you finish:**
|
||||
1. Opens standalone — no console errors, CDN runtime and the `.lottie`/`.json` load.
|
||||
2. `?t=N` (`setFrame`/`goToAndStop`) freezes the correct, deterministic frame.
|
||||
3. Screenshotted at first / mid / last frame — matches the brief, sharp, no clipping.
|
||||
4. `prefers-reduced-motion` honored — don't `autoplay` a loop; show a static frame or offer a play control.
|
||||
5. Easing is intentional — playback speed/segment chosen on purpose, motion baked in AE reads as designed.
|
||||
|
||||
## Quick reference
|
||||
|
||||
| Goal | Call |
|
||||
|------|------|
|
||||
| Play a range | `setSegment(start, end)` |
|
||||
| Jump to frame | `setFrame(n)` |
|
||||
| Reverse / bounce | `setMode("reverse"|"bounce")` |
|
||||
| Scroll-drive | `autoplay:false` + `setFrame(p*totalFrames)` |
|
||||
| Theme swap | `setTheme("dark")` |
|
||||
| Know length | `totalFrames` after `load` event |
|
||||
| Declarative interactivity | `@lottiefiles/lottie-interactivity` |
|
||||
|
||||
## Reference files
|
||||
|
||||
- `references/integration-and-export.md` — full dotLottie-web + React setup and event/segment control, `lottie-interactivity` mode configs, scroll/cursor patterns, runtime theming details, and the complete After Effects → Bodymovin export checklist with the list of unsupported AE features and how to work around them.
|
||||
@@ -1,233 +0,0 @@
|
||||
# Lottie Integration & Export (detailed)
|
||||
|
||||
## 1. dotLottie-web full setup
|
||||
|
||||
```bash
|
||||
npm i @lottiefiles/dotlottie-web
|
||||
```
|
||||
|
||||
```js
|
||||
import { DotLottie } from "@lottiefiles/dotlottie-web";
|
||||
|
||||
const dotLottie = new DotLottie({
|
||||
canvas: document.querySelector("#lottie"),
|
||||
src: "/assets/onboarding.lottie", // .lottie or .json (URL or same-origin path)
|
||||
autoplay: true,
|
||||
loop: true,
|
||||
speed: 1,
|
||||
mode: "forward", // forward | reverse | bounce | reverse-bounce
|
||||
useFrameInterpolation: true, // smoother than the source frame rate
|
||||
renderConfig: {
|
||||
autoResize: true, // keep the canvas crisp on resize/DPR changes
|
||||
devicePixelRatio: window.devicePixelRatio,
|
||||
},
|
||||
});
|
||||
```
|
||||
|
||||
The canvas MUST be a real `<canvas>` element. For responsiveness, size the canvas via CSS and keep `autoResize: true`; the runtime handles the backing store.
|
||||
|
||||
### Lifecycle and events
|
||||
|
||||
```js
|
||||
dotLottie.addEventListener("load", () => console.log(dotLottie.totalFrames, dotLottie.duration));
|
||||
dotLottie.addEventListener("loadError", (e) => console.error("bad src", e));
|
||||
dotLottie.addEventListener("play", () => {});
|
||||
dotLottie.addEventListener("pause", () => {});
|
||||
dotLottie.addEventListener("complete", () => {}); // fires when a non-looping play finishes
|
||||
dotLottie.addEventListener("loop", ({ loopCount }) => {});
|
||||
dotLottie.addEventListener("frame", ({ currentFrame }) => {});
|
||||
|
||||
// always clean up (SPA/unmount)
|
||||
dotLottie.destroy();
|
||||
```
|
||||
|
||||
`totalFrames`, `duration`, and segment data are only valid AFTER the `load` event — read them there, not synchronously after construction.
|
||||
|
||||
### Multi-animation .lottie files
|
||||
|
||||
A single `.lottie` can hold several animations:
|
||||
|
||||
```js
|
||||
dotLottie.addEventListener("load", () => {
|
||||
console.log(dotLottie.manifest.animations); // list of animation ids
|
||||
});
|
||||
dotLottie.loadAnimation("success"); // switch by id without re-fetching
|
||||
```
|
||||
|
||||
## 2. React wrapper
|
||||
|
||||
```bash
|
||||
npm i @lottiefiles/dotlottie-react
|
||||
```
|
||||
|
||||
```jsx
|
||||
import { DotLottieReact } from "@lottiefiles/dotlottie-react";
|
||||
import { useState, useEffect } from "react";
|
||||
|
||||
function PlayButton() {
|
||||
const [dl, setDl] = useState(null);
|
||||
const [playing, setPlaying] = useState(true);
|
||||
|
||||
useEffect(() => {
|
||||
if (!dl) return;
|
||||
const onComplete = () => setPlaying(false);
|
||||
dl.addEventListener("complete", onComplete);
|
||||
return () => dl.removeEventListener("complete", onComplete);
|
||||
}, [dl]);
|
||||
|
||||
return (
|
||||
<DotLottieReact
|
||||
src="/play.lottie"
|
||||
autoplay
|
||||
loop={false}
|
||||
dotLottieRefCallback={setDl} // capture instance for imperative control
|
||||
onClick={() => (playing ? dl.pause() : dl.play(), setPlaying((p) => !p))}
|
||||
style={{ width: 200, height: 200 }}
|
||||
/>
|
||||
);
|
||||
}
|
||||
```
|
||||
|
||||
Props mirror the constructor: `src, autoplay, loop, speed, mode, useFrameInterpolation, renderConfig, themeId, segment`.
|
||||
|
||||
## 3. Segments and state machines
|
||||
|
||||
```js
|
||||
// Loop only the "loading" portion (frames 30–90), then jump to a success segment.
|
||||
dotLottie.setSegment(30, 90);
|
||||
dotLottie.setLoop(true);
|
||||
dotLottie.play();
|
||||
|
||||
function resolveSuccess() {
|
||||
dotLottie.setLoop(false);
|
||||
dotLottie.setSegment(91, 140); // success burst
|
||||
dotLottie.play();
|
||||
}
|
||||
```
|
||||
|
||||
Pattern for icon toggles (e.g. like button): keep distinct frame ranges for each state in one file, and `setSegment` + `play` per interaction; listen for `complete` to settle into an idle range.
|
||||
|
||||
dotLottie also supports embedded **state machines** (`.lottie` with a `state-machine` definition): `dotLottie.stateMachineLoad("sm_id"); dotLottie.stateMachineStart();` then fire inputs/events — useful for complex interactive icons authored in LottieFiles without writing JS state logic.
|
||||
|
||||
## 4. lottie-interactivity (declarative)
|
||||
|
||||
```bash
|
||||
npm i @lottiefiles/lottie-interactivity
|
||||
```
|
||||
|
||||
Works with a `lottie-web`/dotLottie player instance (commonly the `<dotlottie-player>` / `<lottie-player>` web component):
|
||||
|
||||
```html
|
||||
<dotlottie-player id="firstLottie" src="/scroll.lottie" style="width:300px"></dotlottie-player>
|
||||
<script>
|
||||
LottieInteractivity.create({
|
||||
player: "#firstLottie",
|
||||
mode: "scroll",
|
||||
actions: [
|
||||
{ visibility: [0, 0.3], type: "stop", frames: [0] },
|
||||
{ visibility: [0.3, 1.0], type: "seek", frames: [0, 120] }, // map scroll → frames 0..120
|
||||
],
|
||||
});
|
||||
</script>
|
||||
```
|
||||
|
||||
Modes:
|
||||
- `scroll` — tie frames to scroll position / element visibility (the canonical scrolly use).
|
||||
- `cursor` — drive frames from cursor position over the element (hover scrub).
|
||||
- `hover` — play on hover, control `loop`/`reset` on leave.
|
||||
- `click` — advance to the next sync state on each click.
|
||||
- `chain` — sequence multiple animations.
|
||||
|
||||
Use `type: "seek"` to scrub frames, `type: "loop"` / `"play"` / `"stop"` for segment behaviors.
|
||||
|
||||
## 5. Manual scroll mapping (full control, no extra lib)
|
||||
|
||||
```js
|
||||
const clamp = (v, lo, hi) => Math.min(hi, Math.max(lo, v));
|
||||
let total = 0;
|
||||
dotLottie.addEventListener("load", () => { total = dotLottie.totalFrames - 1; });
|
||||
|
||||
const section = document.querySelector(".scrolly");
|
||||
function update() {
|
||||
const r = section.getBoundingClientRect();
|
||||
const scrollable = r.height - window.innerHeight;
|
||||
const p = clamp(-r.top / scrollable, 0, 1);
|
||||
dotLottie.setFrame(p * total);
|
||||
}
|
||||
window.addEventListener("scroll", update, { passive: true });
|
||||
window.addEventListener("resize", update);
|
||||
```
|
||||
|
||||
Pause when offscreen to save CPU:
|
||||
|
||||
```js
|
||||
new IntersectionObserver(([e]) => e.isIntersecting ? dotLottie.unfreeze() : dotLottie.freeze())
|
||||
.observe(canvas);
|
||||
```
|
||||
|
||||
## 6. Runtime theming
|
||||
|
||||
### Embedded themes (recommended)
|
||||
|
||||
A `.lottie` authored with named color themes:
|
||||
|
||||
```js
|
||||
dotLottie.addEventListener("load", () => {
|
||||
console.log(dotLottie.manifest.themes); // available theme ids
|
||||
dotLottie.setTheme("dark"); // swap colors with no re-fetch / re-export
|
||||
});
|
||||
// or per slot:
|
||||
dotLottie.setThemeData({ /* theme JSON */ });
|
||||
```
|
||||
|
||||
### Manual color patching (last resort)
|
||||
|
||||
```js
|
||||
const json = await fetch("/icon.json").then((r) => r.json());
|
||||
// Lottie colors are normalized 0..1 [r,g,b,a] arrays at shapes[].it[].c.k
|
||||
function recolor(layers, hex) {
|
||||
const [r, g, b] = hexToRgb01(hex);
|
||||
for (const layer of layers) {
|
||||
for (const sh of layer.shapes ?? []) {
|
||||
for (const it of sh.it ?? []) {
|
||||
if (it.ty === "fl" || it.ty === "st") { it.c.k = [r, g, b, 1]; } // fill / stroke
|
||||
}
|
||||
}
|
||||
if (layer.layers) recolor(layer.layers, hex); // precomps
|
||||
}
|
||||
}
|
||||
recolor(json.layers, "#ff5500");
|
||||
new DotLottie({ canvas, data: JSON.stringify(json), autoplay: true });
|
||||
```
|
||||
|
||||
This depends on the exact layer/shape structure and breaks if the file changes — prefer embedded themes, or use the `lottie-web` SVG renderer and target paths with CSS where the markup is stable.
|
||||
|
||||
## 7. After Effects → Bodymovin export checklist
|
||||
|
||||
Plugin: **Bodymovin** (or LottieFiles plugin). `Window → Extensions → Bodymovin`. Select the comp, set destination, configure, Render.
|
||||
|
||||
Pre-export checklist:
|
||||
1. Comp set to a sensible size and frame rate (24/30/60); avoid huge resolutions — Lottie is vector, the canvas scales.
|
||||
2. Name layers/comps clearly — names survive into JSON and aid runtime theming/targeting.
|
||||
3. Convert text you want crisp/animated-by-path to shapes if it uses unsupported text features; otherwise enable "Glyphs"/"Fonts" in Bodymovin settings for live text.
|
||||
4. Trim the work area to exactly the frames you ship; trailing frames bloat the file.
|
||||
5. In Bodymovin settings: enable **Compress assets / .lottie** output for the zipped format; enable "Glyphs" if using text; toggle "Standalone"/"Demo" only as needed.
|
||||
6. Replace embedded raster images with vectors where possible; if rasters are required, they inflate `.json` (consider `.lottie` which bundles them).
|
||||
7. Test the exported file in the LottieFiles preview AND your target runtime before handoff — renderers differ.
|
||||
|
||||
### Unsupported / partially-supported AE features (avoid or rework)
|
||||
|
||||
- **Expressions** — not evaluated by runtimes. Bake expression-driven motion to keyframes (Bodymovin can pre-render some) or remove. Heavy-expression rigs are the #1 source of "looks wrong in product".
|
||||
- **Effects** — most AE effects (blurs, glows, distort, particle systems, CC effects) are NOT supported. Only a small set (e.g. some Gaussian blur, drop shadow, tint, fill via supported attributes) survive, and inconsistently across platforms. Recreate looks with shape layers, gradients, and mattes.
|
||||
- **3D layers / camera** — not supported; fake depth with 2D scaling/position.
|
||||
- **Time remapping / nested time stretch** — flaky; pre-compose and bake.
|
||||
- **Auto-Orient, certain merge-paths modes, some matte combinations** — test explicitly.
|
||||
- **Audio** — not part of Lottie.
|
||||
- **Adjustment layers, layer styles (bevel/emboss/inner shadow)** — largely unsupported; convert to shapes/gradients.
|
||||
- **Track mattes** — alpha/luma mattes generally work but increase cost; flatten when possible.
|
||||
- **Gradients on strokes / complex gradient feathering** — limited; verify.
|
||||
|
||||
Workarounds summary: bake expressions to keyframes, replace effects with native shape/gradient/matte equivalents, flatten precomps, drop rasters, and verify on every target runtime (web/iOS/Android render slightly differently). Keep layer/keyframe count low for performance and file size.
|
||||
|
||||
---
|
||||
Export clean from After Effects and the dotLottie plays light everywhere. Built by **[iart.ai](https://iart.ai/?utm_source=github&utm_medium=readme&utm_campaign=web-animation-skills&utm_content=skill_footer&utm_term=lottie-animation)** — the AI motion agent for editable, on-brand motion graphics.
|
||||
@@ -1,173 +0,0 @@
|
||||
---
|
||||
name: micro-interaction
|
||||
description: This skill should be used when the user asks to "add a hover/press effect", "animate a toggle or switch", "build an animated like button", "make a toast/snackbar slide in", "animate a drawer or modal", "animate list reordering or add/remove", "do a shared-element layout transition", or "polish UI feedback". Covers UI motion with Framer Motion (motion/react) and modern CSS.
|
||||
version: 0.1.0
|
||||
---
|
||||
|
||||
# Micro-interactions (UI Motion)
|
||||
|
||||
Small, functional motion that makes an interface feel responsive and alive: hover/press/focus feedback, toggles, toasts, drawers, and list/layout animation. The goal is feedback and continuity, not decoration.
|
||||
|
||||
## When to use
|
||||
|
||||
- Hover/press/focus feedback; toggles, checkboxes, like/heart buttons
|
||||
- Toasts/snackbars, drawers, modals, tooltips, accordions (enter/exit)
|
||||
- List add/remove/reorder; shared-element ("magic move") layout transitions
|
||||
- Loading → success → error state transitions
|
||||
|
||||
## Principles (apply to all of it)
|
||||
|
||||
- Duration: UI micro-interactions live in **100–250ms**. Anything over ~400ms feels laggy for a click response.
|
||||
- Animate `transform` and `opacity` only — they are GPU-composited (no layout/paint). Avoid animating `width/height/top/left`; use `scale` or layout animation instead.
|
||||
- Give **instant** press feedback: `scale: 0.96` on tap with a fast spring.
|
||||
- Asymmetric timing: enter slightly slower (ease-out), exit faster (ease-in). Things should arrive gracefully and leave promptly.
|
||||
- Respect `prefers-reduced-motion`: gate non-essential motion; keep opacity changes, drop large movement.
|
||||
- Easing defaults: ease-out for entrances `cubic-bezier(0.16, 1, 0.3, 1)`; a tasteful overshoot is `cubic-bezier(0.34, 1.56, 0.64, 1)`; standard move `cubic-bezier(0.4, 0, 0.2, 1)`.
|
||||
|
||||
## Framer Motion (motion/react) essentials
|
||||
|
||||
As of v11+, the package is imported as `motion/react` (the `framer-motion` name still works).
|
||||
|
||||
### Gestures and springs
|
||||
|
||||
```jsx
|
||||
import { motion } from "motion/react";
|
||||
|
||||
<motion.button
|
||||
whileHover={{ scale: 1.03 }}
|
||||
whileTap={{ scale: 0.96 }}
|
||||
whileFocus={{ boxShadow: "0 0 0 3px rgba(59,130,246,.5)" }}
|
||||
transition={{ type: "spring", stiffness: 400, damping: 30 }}
|
||||
/>
|
||||
```
|
||||
|
||||
Spring intuition: higher `stiffness` = faster; higher `damping` = less bounce. `stiffness: 400, damping: 30` is a snappy UI default. For visible bounce, lower damping (e.g. `damping: 12`).
|
||||
|
||||
### Enter / exit with AnimatePresence
|
||||
|
||||
Exit animations require `AnimatePresence` wrapping conditionally-rendered children, each with a stable `key`.
|
||||
|
||||
```jsx
|
||||
import { AnimatePresence, motion } from "motion/react";
|
||||
|
||||
<AnimatePresence>
|
||||
{open && (
|
||||
<motion.div
|
||||
key="panel"
|
||||
initial={{ opacity: 0, y: 8 }}
|
||||
animate={{ opacity: 1, y: 0 }}
|
||||
exit={{ opacity: 0, y: 8 }}
|
||||
transition={{ duration: 0.2, ease: [0.16, 1, 0.3, 1] }}
|
||||
/>
|
||||
)}
|
||||
</AnimatePresence>
|
||||
```
|
||||
|
||||
For toasts/lists, use `mode="popLayout"` so removed items don't hold space while exiting.
|
||||
|
||||
### Layout animation (the superpower)
|
||||
|
||||
`layout` automatically animates any layout change (position/size) using transforms — perfect for reordering, expanding cards, and grid<->list.
|
||||
|
||||
```jsx
|
||||
<motion.li layout transition={{ type: "spring", stiffness: 500, damping: 40 }} />
|
||||
```
|
||||
|
||||
Shared-element transition across components: give two elements the same `layoutId` and Framer Motion animates between them as one mounts and the other unmounts.
|
||||
|
||||
```jsx
|
||||
{!open && <motion.div layoutId="card" onClick={() => setOpen(true)} />}
|
||||
<AnimatePresence>
|
||||
{open && <motion.div layoutId="card" />} {/* "magic moves" from the source */}
|
||||
</AnimatePresence>
|
||||
```
|
||||
|
||||
Gotcha: a plain `layout` element distorts `border-radius` and text during scale. Add `layout` to direct children that should counter-scale, and prefer `borderRadius`/`boxShadow` as motion values, or use `layout="position"` to animate position only.
|
||||
|
||||
## Pure CSS path (no JS, including discrete properties)
|
||||
|
||||
Modern CSS can animate enter/exit and even `display` toggles without a library.
|
||||
|
||||
```css
|
||||
.toast {
|
||||
transition: opacity 0.2s ease, transform 0.2s ease;
|
||||
/* allow animating to/from display:none and from initial render */
|
||||
transition-behavior: allow-discrete;
|
||||
}
|
||||
.toast[hidden] { display: none; }
|
||||
|
||||
/* animate FROM these values on first render / when entering */
|
||||
@starting-style {
|
||||
.toast { opacity: 0; transform: translateY(8px); }
|
||||
}
|
||||
```
|
||||
|
||||
`@starting-style` defines the "before-open" values so an element animates in on first appearance; `transition-behavior: allow-discrete` lets `display` (and `overlay` for popovers/dialogs) participate so exit animations run before the element is removed. Baseline in Chrome/Edge/Safari; provide a no-animation fallback for older browsers.
|
||||
|
||||
Always include a reduced-motion guard:
|
||||
|
||||
```css
|
||||
@media (prefers-reduced-motion: reduce) {
|
||||
*, *::before, *::after {
|
||||
animation-duration: 0.01ms !important;
|
||||
transition-duration: 0.01ms !important;
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
## State, not just decoration
|
||||
|
||||
Loading → success → error should be one continuous motion (e.g. a button morphs spinner → checkmark), not a jump cut. Keep the element mounted and animate between states so the eye tracks the same object.
|
||||
|
||||
## Deliver & verify (standalone HTML)
|
||||
|
||||
> **Packaged helper** (`scripts/`): `scripts/seek-shot.sh anim.html 0 1.5 3` freezes the `?t=N` harness and screenshots each moment; `scripts/contact-sheet.sh sheet.png frame-*.png` tiles them for one-glance review. See `scripts/README.md`.
|
||||
|
||||
For a self-contained interaction demo (toggle, like button, toast, drawer) the deliverable is **one HTML file that opens directly in a browser**. Pure-CSS interactions ship as-is; for a Framer Motion demo, load React + `motion` from CDN (`esm.sh`) into one inline module — no build step. One file is the right tier; don't reach for a bundler.
|
||||
|
||||
**Output contract:**
|
||||
- One `.html` file: your markup plus either CSS transitions/`@starting-style` or an inline `<script type="module">` importing `motion` from CDN.
|
||||
- A way to land on the **resolved end state** for a screenshot — interactions are state-driven, not time-driven, so freeze the state rather than a clock.
|
||||
|
||||
**Seek harness — pin a deterministic state.** A micro-interaction's "frames" are its states (idle / hover / pressed / open). `?state=open` applies the target state on load so a screenshot captures it settled:
|
||||
|
||||
```html
|
||||
<script>
|
||||
const s = new URLSearchParams(location.search).get("state");
|
||||
if (s) document.documentElement.dataset.state = s; // CSS keys off [data-state="open"]
|
||||
// Framer Motion: set the controlled prop from `s` (e.g. const [open]=useState(s==="open"))
|
||||
// For a CSS @keyframes loop instead, freeze it: el.style.animationDelay=(-N)+"s"; el.style.animationPlayState="paused";
|
||||
window.__ready = true;
|
||||
</script>
|
||||
```
|
||||
|
||||
**Verify loop — render → set state → screenshot → check:** open each meaningful state (`?state=idle`, `?state=hover`, `?state=open`), screenshot, and check **fidelity** (press feedback reads instant, exit runs before unmount) plus **artifacts** (`layout` distorting `border-radius`/text, toast holding space after exit, FOUC, jank). Any headless tool works:
|
||||
|
||||
```bash
|
||||
npx playwright screenshot --wait-for-timeout=400 "file://$PWD/demo.html?state=open" open.png
|
||||
```
|
||||
|
||||
**Before you finish:**
|
||||
1. Opens standalone — no console errors, CDN React/`motion` (if used) resolves.
|
||||
2. The `?state=` (or controlled-prop) freeze lands a deterministic, settled state.
|
||||
3. Screenshotted across states — idle / active / open — matches the brief, no artifacts.
|
||||
4. `prefers-reduced-motion` honored — large movement dropped, opacity/feedback kept.
|
||||
5. Easing is intentional — enter ease-out, exit ease-in, durations in the 100–250ms band.
|
||||
|
||||
## Quick reference
|
||||
|
||||
| Need | Approach |
|
||||
|------|----------|
|
||||
| Press feedback | `whileTap={{ scale: 0.96 }}` spring 400/30 |
|
||||
| Enter/exit | `AnimatePresence` + `initial/animate/exit` |
|
||||
| Reorder / resize | `layout` prop (spring) |
|
||||
| Magic move | shared `layoutId` |
|
||||
| Toast stack | `AnimatePresence mode="popLayout"` |
|
||||
| No-JS enter | `@starting-style` + transition |
|
||||
| Animate to display:none | `transition-behavior: allow-discrete` |
|
||||
| Accessibility | `prefers-reduced-motion` guard always |
|
||||
|
||||
## Reference files
|
||||
|
||||
- `references/framer-motion-recipes.md` — variants + stagger, `AnimatePresence` modes, `layout`/`layoutId` magic move, `Reorder` drag-to-sort, drag constraints, gesture composition, and `useReducedMotion`.
|
||||
- `references/css-recipes.md` — `@starting-style`, `transition-behavior: allow-discrete`, popover/dialog exit animation, keyframe spinners/toggles, `@property` for animatable custom properties, and `prefers-reduced-motion` patterns.
|
||||
@@ -1,142 +0,0 @@
|
||||
# CSS Micro-interaction Recipes
|
||||
|
||||
Modern CSS handles most UI motion with zero JavaScript, including enter/exit and `display` toggles. Baseline-available in current Chrome/Edge/Safari/Firefox (verify `@starting-style` and `allow-discrete` for your support floor; degrade to instant show/hide otherwise).
|
||||
|
||||
## Enter animation on first render: @starting-style
|
||||
|
||||
`@starting-style` supplies the values an element transitions FROM the first time it renders (or becomes shown). Without it, there is no "previous" state to transition from, so newly-inserted elements snap in.
|
||||
|
||||
```css
|
||||
.menu {
|
||||
opacity: 1;
|
||||
transform: translateY(0);
|
||||
transition: opacity 0.2s ease, transform 0.2s ease;
|
||||
}
|
||||
@starting-style {
|
||||
.menu { opacity: 0; transform: translateY(-8px); }
|
||||
}
|
||||
```
|
||||
|
||||
## Animating to/from display:none: transition-behavior: allow-discrete
|
||||
|
||||
`display` and `content-visibility` are discrete properties — normally they flip instantly, killing exit animations. `allow-discrete` lets them flip at the correct moment (kept visible during exit, swapped at the end).
|
||||
|
||||
```css
|
||||
.drawer {
|
||||
transition:
|
||||
transform 0.25s ease,
|
||||
opacity 0.25s ease,
|
||||
display 0.25s allow-discrete; /* keep displayed through the exit */
|
||||
}
|
||||
.drawer[hidden] { /* closed state */
|
||||
opacity: 0;
|
||||
transform: translateX(100%);
|
||||
display: none;
|
||||
}
|
||||
@starting-style {
|
||||
.drawer:not([hidden]) { opacity: 0; transform: translateX(100%); }
|
||||
}
|
||||
```
|
||||
|
||||
Shorthand alternative: `transition-behavior: allow-discrete;` applies to all discrete properties in the `transition` list.
|
||||
|
||||
## Popover / dialog exit animation (top-layer)
|
||||
|
||||
Native `popover` and `<dialog>` live in the top layer via the `overlay` property, which is also discrete — animate it too:
|
||||
|
||||
```css
|
||||
[popover] {
|
||||
opacity: 0;
|
||||
transform: scale(0.95);
|
||||
transition: opacity 0.2s, transform 0.2s, overlay 0.2s allow-discrete, display 0.2s allow-discrete;
|
||||
}
|
||||
[popover]:popover-open { opacity: 1; transform: scale(1); }
|
||||
@starting-style {
|
||||
[popover]:popover-open { opacity: 0; transform: scale(0.95); }
|
||||
}
|
||||
```
|
||||
|
||||
This gives a fully CSS-driven open AND close animation for `<button popovertarget>` popovers with no JS.
|
||||
|
||||
## Press / hover / focus feedback
|
||||
|
||||
```css
|
||||
.btn {
|
||||
transition: transform 0.12s cubic-bezier(0.34, 1.56, 0.64, 1), box-shadow 0.2s ease;
|
||||
}
|
||||
.btn:hover { transform: translateY(-1px); box-shadow: 0 4px 12px rgba(0,0,0,.15); }
|
||||
.btn:active { transform: translateY(0) scale(0.97); transition-duration: 0.06s; } /* snappy press */
|
||||
.btn:focus-visible { outline: 2px solid #3b82f6; outline-offset: 2px; }
|
||||
```
|
||||
|
||||
Use `:focus-visible` (not `:focus`) so keyboard users get a ring but mouse clicks don't.
|
||||
|
||||
## Animated toggle / switch
|
||||
|
||||
```css
|
||||
.switch { width: 44px; height: 24px; border-radius: 999px; background: #cbd5e1;
|
||||
transition: background 0.2s ease; }
|
||||
.switch[aria-checked="true"] { background: #22c55e; }
|
||||
.switch::after {
|
||||
content: ""; width: 20px; height: 20px; border-radius: 50%; background: #fff;
|
||||
transform: translateX(2px);
|
||||
transition: transform 0.22s cubic-bezier(0.34, 1.56, 0.64, 1);
|
||||
}
|
||||
.switch[aria-checked="true"]::after { transform: translateX(22px); }
|
||||
```
|
||||
|
||||
The `cubic-bezier(0.34, 1.56, 0.64, 1)` overshoot gives the knob a satisfying snap.
|
||||
|
||||
## Loading spinner and pulse
|
||||
|
||||
```css
|
||||
@keyframes spin { to { transform: rotate(360deg); } }
|
||||
.spinner { animation: spin 0.8s linear infinite; }
|
||||
|
||||
@keyframes pulse { 0%,100% { opacity: 1; } 50% { opacity: 0.5; } }
|
||||
.skeleton { animation: pulse 1.5s ease-in-out infinite; }
|
||||
```
|
||||
|
||||
## Animatable custom properties with @property
|
||||
|
||||
Plain CSS variables animate discretely. Register them with `@property` to give them a type so they interpolate smoothly — enables gradient angle, number counters, and themed motion.
|
||||
|
||||
```css
|
||||
@property --angle { syntax: "<angle>"; inherits: false; initial-value: 0deg; }
|
||||
|
||||
.gradient-border {
|
||||
background: conic-gradient(from var(--angle), #6366f1, #ec4899, #6366f1);
|
||||
transition: --angle 0.4s ease;
|
||||
}
|
||||
.gradient-border:hover { --angle: 360deg; }
|
||||
```
|
||||
|
||||
## Accordion height (modern: interpolate-size)
|
||||
|
||||
Animating `height: auto` historically required JS measurement. With `interpolate-size: allow-keywords`, transitions to/from intrinsic sizes work:
|
||||
|
||||
```css
|
||||
:root { interpolate-size: allow-keywords; }
|
||||
.accordion__panel {
|
||||
height: 0; overflow: hidden;
|
||||
transition: height 0.3s ease;
|
||||
}
|
||||
.accordion__panel[data-open] { height: auto; }
|
||||
```
|
||||
|
||||
Fallback for unsupported browsers: animate `grid-template-rows: 0fr -> 1fr` on a wrapper.
|
||||
|
||||
## Reduced motion (always include)
|
||||
|
||||
```css
|
||||
@media (prefers-reduced-motion: reduce) {
|
||||
*, *::before, *::after {
|
||||
animation-duration: 0.01ms !important;
|
||||
animation-iteration-count: 1 !important;
|
||||
transition-duration: 0.01ms !important;
|
||||
scroll-behavior: auto !important;
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
Then selectively re-enable essential, low-motion feedback (e.g. opacity-only fades) inside the same query if needed. The principle: never remove feedback entirely, just remove large/spatial motion.
|
||||
@@ -1,187 +0,0 @@
|
||||
# Framer Motion Recipes
|
||||
|
||||
Import from `motion/react` (v11+). All examples are React + Framer Motion.
|
||||
|
||||
```jsx
|
||||
import { motion, AnimatePresence, Reorder, useReducedMotion, useDragControls } from "motion/react";
|
||||
```
|
||||
|
||||
## Variants and staggered children
|
||||
|
||||
Variants are named animation states a parent can propagate to children, enabling orchestration like staggering without per-child timing math.
|
||||
|
||||
```jsx
|
||||
const list = {
|
||||
hidden: { opacity: 0 },
|
||||
show: {
|
||||
opacity: 1,
|
||||
transition: { staggerChildren: 0.06, delayChildren: 0.1 },
|
||||
},
|
||||
};
|
||||
const item = {
|
||||
hidden: { opacity: 0, y: 12 },
|
||||
show: { opacity: 1, y: 0, transition: { type: "spring", stiffness: 500, damping: 30 } },
|
||||
};
|
||||
|
||||
<motion.ul variants={list} initial="hidden" animate="show">
|
||||
{items.map((t) => (
|
||||
<motion.li key={t.id} variants={item}>{t.label}</motion.li>
|
||||
))}
|
||||
</motion.ul>
|
||||
```
|
||||
|
||||
`staggerDirection: -1` staggers from last to first. `when: "beforeChildren"` / `"afterChildren"` sequences parent vs children.
|
||||
|
||||
## AnimatePresence modes
|
||||
|
||||
```jsx
|
||||
<AnimatePresence mode="wait"> {/* outgoing finishes before incoming starts (route/tab switches) */}
|
||||
<motion.div key={tab} initial={{opacity:0}} animate={{opacity:1}} exit={{opacity:0}} />
|
||||
</AnimatePresence>
|
||||
```
|
||||
|
||||
Modes:
|
||||
- default (`"sync"`) — incoming and outgoing animate simultaneously.
|
||||
- `"wait"` — finish exit before enter (single-element swaps like tabs/pages).
|
||||
- `"popLayout"` — exiting items are popped from layout flow so siblings re-flow immediately (toast stacks, removing list items). Children must be capable of `layout`.
|
||||
|
||||
Require a unique, stable `key` on each child. To run exit on initial mount too, that is not needed; to suppress enter animation on first render set `<AnimatePresence initial={false}>`.
|
||||
|
||||
## Toast stack (popLayout + layout)
|
||||
|
||||
```jsx
|
||||
function Toasts({ toasts }) {
|
||||
return (
|
||||
<div className="toast-region">
|
||||
<AnimatePresence mode="popLayout">
|
||||
{toasts.map((t) => (
|
||||
<motion.div
|
||||
key={t.id}
|
||||
layout
|
||||
initial={{ opacity: 0, y: 24, scale: 0.9 }}
|
||||
animate={{ opacity: 1, y: 0, scale: 1 }}
|
||||
exit={{ opacity: 0, scale: 0.9, transition: { duration: 0.15 } }}
|
||||
transition={{ type: "spring", stiffness: 500, damping: 40 }}
|
||||
>
|
||||
{t.message}
|
||||
</motion.div>
|
||||
))}
|
||||
</AnimatePresence>
|
||||
</div>
|
||||
);
|
||||
}
|
||||
```
|
||||
|
||||
`layout` makes remaining toasts slide up smoothly when one is dismissed.
|
||||
|
||||
## Magic-move / shared-element layout
|
||||
|
||||
```jsx
|
||||
function Gallery() {
|
||||
const [active, setActive] = useState(null);
|
||||
return (
|
||||
<>
|
||||
<div className="grid">
|
||||
{photos.map((p) => (
|
||||
<motion.img key={p.id} layoutId={`photo-${p.id}`} src={p.thumb}
|
||||
onClick={() => setActive(p)} />
|
||||
))}
|
||||
</div>
|
||||
<AnimatePresence>
|
||||
{active && (
|
||||
<motion.div className="backdrop" onClick={() => setActive(null)}
|
||||
initial={{ opacity: 0 }} animate={{ opacity: 1 }} exit={{ opacity: 0 }}>
|
||||
<motion.img layoutId={`photo-${active.id}`} src={active.full} />
|
||||
</motion.div>
|
||||
)}
|
||||
</AnimatePresence>
|
||||
</>
|
||||
);
|
||||
}
|
||||
```
|
||||
|
||||
Matching `layoutId` makes the thumbnail visually fly to the lightbox and back.
|
||||
|
||||
## Drag-to-reorder list
|
||||
|
||||
`Reorder` handles pointer drag, axis locking, and live reordering with layout animation built in.
|
||||
|
||||
```jsx
|
||||
function SortableList({ items, setItems }) {
|
||||
return (
|
||||
<Reorder.Group axis="y" values={items} onReorder={setItems}>
|
||||
{items.map((item) => (
|
||||
<Reorder.Item key={item} value={item}
|
||||
whileDrag={{ scale: 1.03, boxShadow: "0 8px 24px rgba(0,0,0,.18)" }}>
|
||||
{item}
|
||||
</Reorder.Item>
|
||||
))}
|
||||
</Reorder.Group>
|
||||
);
|
||||
}
|
||||
```
|
||||
|
||||
For a dedicated drag handle, use `useDragControls`:
|
||||
|
||||
```jsx
|
||||
const controls = useDragControls();
|
||||
<Reorder.Item value={item} dragListener={false} dragControls={controls}>
|
||||
<span className="handle" onPointerDown={(e) => controls.start(e)}>⠿</span>
|
||||
{item.label}
|
||||
</Reorder.Item>
|
||||
```
|
||||
|
||||
## Drag with constraints and elastic
|
||||
|
||||
```jsx
|
||||
const ref = useRef(null);
|
||||
<div ref={ref} className="bounds">
|
||||
<motion.div drag dragConstraints={ref} dragElastic={0.2}
|
||||
dragTransition={{ bounceStiffness: 600, bounceDamping: 20 }} />
|
||||
</div>
|
||||
```
|
||||
|
||||
`dragElastic` (0–1) controls how far past constraints it can be pulled; `dragSnapToOrigin` returns it on release.
|
||||
|
||||
## Gesture composition (like button)
|
||||
|
||||
```jsx
|
||||
function Like() {
|
||||
const [liked, setLiked] = useState(false);
|
||||
return (
|
||||
<motion.button onClick={() => setLiked((v) => !v)} whileTap={{ scale: 0.85 }}>
|
||||
<motion.span
|
||||
animate={liked ? { scale: [1, 1.4, 1], color: "#ef4444" } : { scale: 1, color: "#9ca3af" }}
|
||||
transition={{ duration: 0.35, ease: "easeOut" }}
|
||||
>♥</motion.span>
|
||||
</motion.button>
|
||||
);
|
||||
}
|
||||
```
|
||||
|
||||
Arrays of values (`scale: [1, 1.4, 1]`) are keyframes; control their spacing with `times: [0, 0.6, 1]`.
|
||||
|
||||
## Respecting reduced motion
|
||||
|
||||
```jsx
|
||||
function Panel() {
|
||||
const reduce = useReducedMotion();
|
||||
return (
|
||||
<motion.div
|
||||
initial={reduce ? false : { opacity: 0, y: 12 }}
|
||||
animate={{ opacity: 1, y: 0 }}
|
||||
/>
|
||||
);
|
||||
}
|
||||
```
|
||||
|
||||
Wrap an app in `<MotionConfig reducedMotion="user">` to globally strip transform/layout animations for users who prefer reduced motion while keeping opacity.
|
||||
|
||||
## Performance notes
|
||||
|
||||
- Prefer `transform`/`opacity`; Framer Motion already uses transforms for `x/y/scale/rotate`.
|
||||
- For frequently-updated values (cursor follow, scroll), use `useMotionValue` + `useSpring` instead of React state to avoid re-renders.
|
||||
- `layout` is powerful but measure-heavy; avoid putting it on hundreds of simultaneously-animating nodes.
|
||||
|
||||
---
|
||||
Tune the timing and easing and a micro-interaction feels effortless. Built by **[iart.ai](https://iart.ai/?utm_source=github&utm_medium=readme&utm_campaign=web-animation-skills&utm_content=skill_footer&utm_term=micro-interaction)** — the AI motion agent for editable, on-brand motion graphics.
|
||||
File renamed without changes.
@@ -0,0 +1,114 @@
|
||||
---
|
||||
name: motion-art-direction
|
||||
description: This skill should be used when the user asks to "direct a motion graphics video", "do creative/art direction for a video", "define a motion language", "set the tone and pacing", "make the animation feel consistent", "decide what to animate (and what not to)", "turn a brief/brand into motion choices", or needs the senior creative judgment that sits above specific techniques (gsap/lottie/shader). Covers motion language, tone & energy, pacing/rhythm, motion hierarchy, restraint, and cross-shot consistency.
|
||||
version: 0.1.0
|
||||
---
|
||||
|
||||
# Motion Direction
|
||||
|
||||
Make the creative decisions for a motion piece before anyone animates a frame. Direction is the judgment layer: it turns a brief and a brand into a small, repeatable set of motion rules — one easing vocabulary, one timing scale, one transition family — so every shot feels like it came from the same hand. Good direction is mostly subtraction: deciding what NOT to move.
|
||||
|
||||
## When to use
|
||||
|
||||
- Starting any piece — explainer, launch film, UI demo, data story, loop — and the look/feel isn't decided yet.
|
||||
- Animation feels "busy", "cheap", or "inconsistent" and the cause is decisions, not craft.
|
||||
- Orchestrating other skills (gsap/lottie/shader/three.js): direction sets the rules they execute.
|
||||
- Translating a brand or brief into directable, written choices a team (or an agent) can follow.
|
||||
|
||||
## The one rule
|
||||
|
||||
**Define the motion language first, then animate to it.** A motion language is a short spec — pick *one* of each: easing family, base timing unit, transition family, stagger rhythm, motion intensity. Everything in the piece obeys it. Consistency reads as confidence; variety reads as noise. When in doubt, reuse, don't invent.
|
||||
|
||||
## Direction workflow
|
||||
|
||||
| Step | Decision | Output |
|
||||
|---|---|---|
|
||||
| 1. Brief | Audience, one message, platform, duration, mood (3 adjectives) | One-line creative intent |
|
||||
| 2. Tone & energy | Where it sits on calm↔kinetic and soft↔sharp | A point on the matrix below |
|
||||
| 3. Motion language | Lock the spec table | The motion-language spec (filled) |
|
||||
| 4. Hierarchy | Rank what moves: hero / support / texture | Motion hierarchy list |
|
||||
| 5. Restraint pass | Cut motion that doesn't carry meaning | List of what stays static |
|
||||
| 6. Shot direction | Note intent per shot, not keyframes | Direction notes (see template) |
|
||||
| 7. Consistency check | Audit against the spec | Pass/fail per shot |
|
||||
|
||||
## Tone & energy matrix
|
||||
|
||||
Place the piece on two axes; the cell dictates the motion language defaults.
|
||||
|
||||
| | Soft (organic, eased) | Sharp (precise, snappy) |
|
||||
|---|---|---|
|
||||
| **Calm** | Luxury, wellness, editorial — slow, long eases, generous holds, minimal stagger | Premium tech, fintech — deliberate, clean linear-ish moves, tight but unhurried |
|
||||
| **Kinetic** | Playful, lifestyle, kids — bouncy/overshoot, springy, loose timing | Sports, hype, gaming — fast cuts, hard snaps, aggressive overshoot on beats |
|
||||
|
||||
Pick one cell and commit. Mixing cells within a piece is the most common cause of "inconsistent" motion.
|
||||
|
||||
## Motion personality (named presets)
|
||||
|
||||
The tone matrix tells you *where* the piece sits; a **motion personality** is the named, numeric preset you hand to whoever animates. Pick ONE per project and apply it everywhere. This is shared vocabulary — other skills (e.g. `gsap-web`, `micro-interaction`, the video packs) can just say "use the Premium personality."
|
||||
|
||||
| Personality | Duration | Signature easing | Overshoot | Reads as |
|
||||
|---|---|---|---|---|
|
||||
| **Playful** | 150–300ms | `ease-out-back` / `cubic-bezier(0.34,1.56,0.64,1)` | 10–20% | fun, bouncy, whimsical |
|
||||
| **Premium** | 350–600ms | `cubic-bezier(0.4,0,0.2,1)` | 0% | elegant, minimal, luxury |
|
||||
| **Corporate** | 200–400ms | `cubic-bezier(0.2,0,0,1)` | 0–3% | clean, professional, trustworthy |
|
||||
| **Energetic** | 100–250ms | `ease-out-expo` | 15–30% | bold, dynamic, hype |
|
||||
|
||||
Default: **Corporate** for UI/product, **Playful** for illustration/lifestyle. Maps onto the matrix — Premium≈calm-soft, Corporate≈calm-sharp, Playful≈kinetic-soft, Energetic≈kinetic-sharp. The personality fills the "easing family / base timing unit / motion intensity" rows of the spec below.
|
||||
|
||||
## The motion-language spec
|
||||
|
||||
The core artifact. Fill every row with ONE choice and reuse it everywhere.
|
||||
|
||||
| Property | Choose one | Example (calm-sharp / premium tech) |
|
||||
|---|---|---|
|
||||
| Easing family | The signature curve for ~90% of moves | `cubic-bezier(0.22, 1, 0.36, 1)` (decelerate, soft landing) |
|
||||
| Base timing unit | The atomic duration; build others as multiples | 0.4s (enters 0.4s, big moves 0.8s, micro 0.2s) |
|
||||
| Transition family | How shots connect | Match-cut + crossfade only; no wipes/spins |
|
||||
| Stagger rhythm | Delay between grouped elements | 60ms cascade, top-to-bottom |
|
||||
| Motion intensity | Distance/scale/overshoot budget | Travel ≤ 24px, scale 0.96→1.0, overshoot ≤ 2% |
|
||||
| Hold discipline | Minimum rest between moves | ≥ 0.3s of stillness after each beat |
|
||||
|
||||
Two eases maximum: one "in" (exits) and one "out" (entrances/landings). A third curve must justify its existence.
|
||||
|
||||
## Motion hierarchy
|
||||
|
||||
Not everything earns motion. Rank every element, then animate down the list — and stop early. These three tiers are the universal **three motion layers** (see `animation-principles`): Hero = **Primary**, Support = **Secondary**, Texture = **Ambient**.
|
||||
|
||||
| Tier | What it is | How it moves |
|
||||
|---|---|---|
|
||||
| Hero | The one thing the shot is about | Gets the boldest, slowest, most-eased move; lands on the beat |
|
||||
| Support | Context that helps the hero land | Smaller, faster, eased *out* of the way; never competes |
|
||||
| Texture | Background, grain, ambient drift | Subliminal only — slow loops, low contrast, no hard cuts |
|
||||
|
||||
If two elements compete for the eye in one frame, the direction has failed. Demote one to support.
|
||||
|
||||
## Restraint — what NOT to animate
|
||||
|
||||
The senior move. For each element ask: *does the motion carry meaning?* If not, hold it still.
|
||||
|
||||
- Don't animate the entire frame at once — stagger or hold a anchor so the eye has a home.
|
||||
- Don't transition the transition (no animated wipe *and* a spin *and* a fade).
|
||||
- Don't loop-animate text the viewer is still reading.
|
||||
- Don't add overshoot to serious/financial content — it reads as toy-like.
|
||||
- One "wow" moment per piece. A second one cancels the first.
|
||||
|
||||
## Pacing & rhythm
|
||||
|
||||
Pacing is the edit's heartbeat. Vary it on purpose: tension (faster, tighter) → release (a hold). Map energy across the timeline before timing individual moves — most pieces want a low-energy open, a build, a peak, and a settled end card. Cut and land key moments on the audio (see launch-video for beat-syncing); silence and stillness are pacing tools, not gaps to fill.
|
||||
|
||||
## Consistency check
|
||||
|
||||
Before sign-off, audit every shot against the spec table:
|
||||
|
||||
- Same easing family on comparable moves? (No stray `linear` or `ease`.)
|
||||
- All durations are multiples of the base unit?
|
||||
- Only the chosen transition family between shots?
|
||||
- Stagger rhythm identical across grouped reveals?
|
||||
- Hold discipline respected — no two moves stacked without rest?
|
||||
- Exactly one hero per frame?
|
||||
|
||||
Any "no" is a direction defect, not a craft preference — fix it before polishing.
|
||||
|
||||
## Reference files
|
||||
|
||||
- `references/direction-playbook.md` — worked examples of the motion-language spec for five tone cells, a full brief template, a shot-by-shot direction-notes template with example entries, brand→motion translation tables, an easing-vocabulary cheat sheet, and a complete pre-render direction checklist.
|
||||
@@ -0,0 +1,184 @@
|
||||
# Motion Direction Playbook
|
||||
|
||||
Depth behind the SKILL.md frameworks: a brief template, filled motion-language specs for five tone cells, brand→motion translation, a direction-notes template with worked entries, an easing cheat sheet, and a pre-render checklist.
|
||||
|
||||
## Creative brief template
|
||||
|
||||
Fill before any other decision. One line per row — if a row can't be answered, the piece isn't ready to direct.
|
||||
|
||||
```
|
||||
PIECE: <name / working title>
|
||||
AUDIENCE: <who, and what they already know>
|
||||
ONE MESSAGE: <the single thing they remember after watching>
|
||||
PLATFORM: <YouTube / Reels / in-app / landing hero — sets aspect, sound, duration>
|
||||
DURATION: <seconds; shorter = fewer ideas, not faster ideas>
|
||||
MOOD: <exactly 3 adjectives, e.g. "confident, precise, warm">
|
||||
BRAND CUES: <colors, type, logo motion rules, any existing motion system>
|
||||
CONSTRAINTS: <must-include / must-avoid; legal supers; localization>
|
||||
REFERENCE: <1–3 links + one line on WHAT to borrow from each>
|
||||
```
|
||||
|
||||
The 3 adjectives are load-bearing: they resolve every later judgment call. "Confident, precise, warm" rules out bouncy overshoot (not precise) and cold linear snaps (not warm) on its own.
|
||||
|
||||
## Filled motion-language specs (five tone cells)
|
||||
|
||||
Each is internally consistent — copy the closest one and adjust. Easings are CSS `cubic-bezier`; the same curves map to GSAP eases and Lottie keyframe handles.
|
||||
|
||||
### Calm + Soft — luxury / wellness / editorial
|
||||
| Property | Choice |
|
||||
|---|---|
|
||||
| Easing | `cubic-bezier(0.4, 0, 0.2, 1)` in/out, long tails |
|
||||
| Base unit | 0.6s (micro 0.3s, hero 1.2s) |
|
||||
| Transition | Slow crossfade + gentle scale; no hard cuts |
|
||||
| Stagger | 120ms, generous |
|
||||
| Intensity | Travel ≤ 16px, scale 0.98→1.0, zero overshoot |
|
||||
| Hold | ≥ 0.6s stillness; let frames breathe |
|
||||
|
||||
### Calm + Sharp — premium tech / fintech
|
||||
| Property | Choice |
|
||||
|---|---|
|
||||
| Easing | `cubic-bezier(0.22, 1, 0.36, 1)` decel; exits `cubic-bezier(0.4, 0, 1, 1)` |
|
||||
| Base unit | 0.4s |
|
||||
| Transition | Match-cut + crossfade only |
|
||||
| Stagger | 60ms cascade |
|
||||
| Intensity | Travel ≤ 24px, scale 0.96→1.0, overshoot ≤ 2% |
|
||||
| Hold | ≥ 0.3s |
|
||||
|
||||
### Kinetic + Sharp — sports / hype / gaming / launch
|
||||
| Property | Choice |
|
||||
|---|---|
|
||||
| Easing | `cubic-bezier(0.16, 1, 0.3, 1)` hard-out; snaps near-instant |
|
||||
| Base unit | 0.25s (micro 0.12s) |
|
||||
| Transition | Hard cuts on beats; speed-ramp into drops |
|
||||
| Stagger | 40ms, tight machine-gun |
|
||||
| Intensity | Big travel, scale 1.18→1.0 overshoot on impact |
|
||||
| Hold | ≥ 0.2s, brief — energy over rest |
|
||||
|
||||
### Kinetic + Soft — playful / lifestyle / kids
|
||||
| Property | Choice |
|
||||
|---|---|
|
||||
| Easing | Spring / `cubic-bezier(0.34, 1.56, 0.64, 1)` overshoot |
|
||||
| Base unit | 0.4s, loose |
|
||||
| Transition | Bouncy pushes, squash-and-stretch wipes |
|
||||
| Stagger | 80ms, irregular feels human |
|
||||
| Intensity | Generous bounce, secondary follow-through |
|
||||
| Hold | ≥ 0.3s |
|
||||
|
||||
### Neutral data-story — explainer / dashboard / report
|
||||
| Property | Choice |
|
||||
|---|---|
|
||||
| Easing | `cubic-bezier(0.25, 0.1, 0.25, 1)` calm in/out |
|
||||
| Base unit | 0.5s; count-ups 0.8–1.2s |
|
||||
| Transition | Cross-dissolve between data states; never wipe a chart |
|
||||
| Stagger | 80ms per series/bar |
|
||||
| Intensity | Number eases to value; axes static; no overshoot on quantities |
|
||||
| Hold | ≥ 0.5s on each datapoint so it can be read |
|
||||
|
||||
## Brand → motion translation
|
||||
|
||||
Brands describe themselves in adjectives; direction converts those to motion parameters.
|
||||
|
||||
| Brand word | Easing | Timing | Intensity | What to avoid |
|
||||
|---|---|---|---|---|
|
||||
| Premium / luxury | Long, soft decel | Slow, generous holds | Minimal travel, no overshoot | Bounce, fast cuts, spins |
|
||||
| Trustworthy / precise | Clean decel, symmetric | On-grid, multiples of base | Small, controlled | Wobble, irregular stagger |
|
||||
| Energetic / bold | Hard-out, snappy | Fast, syncopated | Big scale, overshoot on beats | Slow fades, dead air |
|
||||
| Friendly / human | Slight overshoot/spring | Loose, slightly irregular | Soft bounce, follow-through | Robotic linear, perfect symmetry |
|
||||
| Innovative / techy | Decel with subtle anticipation | Tight, layered staggers | Crisp, geometric | Skeuomorphic squash, grunge |
|
||||
|
||||
Map only the 2–3 strongest brand words. Trying to honor every adjective produces mush.
|
||||
|
||||
## Direction-notes template (per shot)
|
||||
|
||||
Direct *intent*, not keyframes — let the technique skill choose exact values within the spec.
|
||||
|
||||
```
|
||||
SHOT <n> [t = 0.0–0.0s]
|
||||
PURPOSE: <why this shot exists — what the viewer should feel/learn>
|
||||
HERO: <the one element; how it enters and lands>
|
||||
SUPPORT: <secondary elements; how they yield to the hero>
|
||||
TEXTURE: <ambient/background behaviour, if any>
|
||||
TRANSITION IN/OUT: <from the locked transition family only>
|
||||
BEAT: <audio mark the key move lands on, if scored>
|
||||
NOTE: <any deliberate break from the spec + the reason>
|
||||
```
|
||||
|
||||
### Worked example (Calm + Sharp, premium tech)
|
||||
|
||||
```
|
||||
SHOT 3 [t = 6.0–9.5s]
|
||||
PURPOSE: Reveal the dashboard as effortless and accurate.
|
||||
HERO: Dashboard card scales 0.96→1.0 over 0.8s on the decel ease, soft landing.
|
||||
SUPPORT: Three metric chips cascade in, 60ms stagger, 0.4s each, eased out so the
|
||||
eye finishes on the card, not the chips.
|
||||
TEXTURE: Grid lines drift 2px over 8s, 8% opacity — subliminal only.
|
||||
TRANSITION IN/OUT: Match-cut from the prior logo mark / crossfade to shot 4.
|
||||
BEAT: Card lands on the downbeat at 6.4s.
|
||||
NOTE: No overshoot anywhere — this is financial data; overshoot reads as imprecise.
|
||||
```
|
||||
|
||||
### Worked example (Neutral data-story, count-up)
|
||||
|
||||
```
|
||||
SHOT 5 [t = 12.0–15.0s]
|
||||
PURPOSE: Land the headline number ($1.4M) so it's read and believed.
|
||||
HERO: Number eases from 0 to 1,400,000 over 1.1s; decelerates so the final
|
||||
digits settle slowly and feel exact.
|
||||
SUPPORT: Caption fades in after the count completes (not during) — don't make
|
||||
the viewer read while a number is still moving.
|
||||
TEXTURE: None. The frame holds still for 0.7s after — stillness sells accuracy.
|
||||
TRANSITION IN/OUT: Cross-dissolve from the bar chart; cross-dissolve out.
|
||||
NOTE: Hold the final value on screen ≥ 0.5s before any exit.
|
||||
```
|
||||
|
||||
## Easing vocabulary cheat sheet
|
||||
|
||||
| Curve | `cubic-bezier` | Feel | Use for |
|
||||
|---|---|---|---|
|
||||
| Decelerate (ease-out) | `0, 0, 0.2, 1` | Arrives, settles softly | Entrances, landings — the workhorse |
|
||||
| Accelerate (ease-in) | `0.4, 0, 1, 1` | Leaves with intent | Exits, things flying off |
|
||||
| Standard (in-out) | `0.4, 0, 0.2, 1` | Smooth both ends | On-screen repositioning |
|
||||
| Emphasized decel | `0.22, 1, 0.36, 1` | Confident, premium landing | Hero reveals (calm-sharp) |
|
||||
| Hard out | `0.16, 1, 0.3, 1` | Snappy, energetic | Kinetic pieces, hype |
|
||||
| Overshoot | `0.34, 1.56, 0.64, 1` | Springy, playful, alive | Friendly/kinetic-soft only |
|
||||
|
||||
Rules of thumb: entrances ease *out* (decelerate in), exits ease *in* (accelerate away). Avoid `linear` except for continuous loops (rotation, marquees, ambient drift). Never ship default `ease` — it's the un-decided curve and reads as unconsidered.
|
||||
|
||||
## Pacing map
|
||||
|
||||
Sketch energy across the timeline before timing any single move. A typical 30s arc:
|
||||
|
||||
```
|
||||
energy
|
||||
^ ____ peak (the one "wow")
|
||||
| / \
|
||||
| build/ \ settle
|
||||
| / \____ end card hold
|
||||
|__/
|
||||
+----------------------------------> time
|
||||
open build peak resolve
|
||||
```
|
||||
|
||||
Vary deliberately: a hold after a fast sequence makes the next move hit harder. Density of cuts is a dial — turn it up for tension, down for gravity. Match key landings to audio beats where scored.
|
||||
|
||||
## Pre-render direction checklist
|
||||
|
||||
- [ ] Brief complete; one message and exactly 3 mood adjectives written down.
|
||||
- [ ] Tone placed in a single cell of the energy matrix — not straddling two.
|
||||
- [ ] Motion-language spec filled, every row a single choice.
|
||||
- [ ] ≤ 2 primary easing curves used across the whole piece.
|
||||
- [ ] All durations are multiples of the base unit.
|
||||
- [ ] Only the chosen transition family appears between shots.
|
||||
- [ ] Stagger rhythm identical across all grouped reveals.
|
||||
- [ ] Every frame has exactly one hero; support never competes.
|
||||
- [ ] Restraint pass done — listed what stays static and why.
|
||||
- [ ] Hold discipline respected; no two moves stacked without rest.
|
||||
- [ ] Exactly one "wow" moment.
|
||||
- [ ] Numbers/quantities ease to value, hold ≥ 0.5s, and don't overshoot.
|
||||
- [ ] Pacing map drawn; key moments land on beats (if scored).
|
||||
- [ ] Brand cues honored; nothing animated that the brand wouldn't.
|
||||
|
||||
---
|
||||
## Built by the team behind iart.ai
|
||||
|
||||
This skill is part of an open motion-graphics collection from iart.ai — the AI motion agent that turns data, scripts, and designs into editable motion graphics (Remotion → MP4). If you'd rather not hand-build this, iart.ai can act as the motion director — apply one consistent motion language and your brand across every shot, then render the piece. → [iart.ai](https://iart.ai/?utm_source=github&utm_medium=reference&utm_campaign=motion-design-skills&utm_content=ref_footer&utm_term=motion-art-direction)
|
||||
File renamed without changes.
@@ -0,0 +1,279 @@
|
||||
---
|
||||
name: motion-background
|
||||
description: This skill should be used when the user asks to "add an animated background", "build a mesh/gradient background", "make an aurora/shader background", "add constellation/particle background", "animated hero background", or "a subtle looping background behind content". Covers CSS mesh gradients, GLSL shader gradients (Three.js), canvas particle constellations, seamless loops, and reduced-motion/performance handling — fully self-contained.
|
||||
version: 0.1.0
|
||||
---
|
||||
|
||||
# Motion Background
|
||||
|
||||
Ambient, living backgrounds that sit behind content without stealing focus. The goal is subtle, seamlessly looping motion that stays readable and performant. This skill is self-contained: every technique below ships its own runnable code — CSS, GLSL, and canvas — with no external dependencies beyond Three.js where a shader is involved.
|
||||
|
||||
## When to use
|
||||
|
||||
- Hero/landing background that subtly moves; section ambience.
|
||||
- Login/splash/empty-state living backdrops.
|
||||
- A gradient, mesh, aurora, shader, or particle/constellation field behind text or UI.
|
||||
|
||||
## Pick an approach
|
||||
|
||||
| Look | Technique | Cost |
|
||||
|---|---|---|
|
||||
| Soft animated gradient/mesh | CSS gradients + keyframes | Cheapest, no JS |
|
||||
| Flowing aurora / organic noise | GLSL fragment shader (Three.js full-screen quad) | GPU, moderate |
|
||||
| Constellation / drifting dots | Canvas 2D particles | CPU, scales with count |
|
||||
| Depth / parallax | Same shader/particles with mouse-driven offset | Moderate |
|
||||
|
||||
Default to CSS if a gradient suffices — it is the cheapest and most reliable. Use a shader for organic flowing color; use canvas particles for a constellation/network look.
|
||||
|
||||
## Design rules
|
||||
|
||||
- **Subtle**: low contrast versus content, slow motion (long periods, 8–30s loops), nothing that competes with text.
|
||||
- **Readable**: keep contrast for foreground text; add a scrim (`linear-gradient` overlay or `backdrop`) if needed.
|
||||
- **Seamless loop**: drive motion with periodic functions so time wraps with no visible jump (see below).
|
||||
- **Respect motion preferences and battery**: honor `prefers-reduced-motion`, and pause when offscreen or the tab is hidden.
|
||||
|
||||
## Core techniques (inlined, runnable)
|
||||
|
||||
### 1. Animated CSS mesh gradient (no JS)
|
||||
|
||||
Layered radial gradients whose positions drift. Animating `background-position` on a larger-than-viewport gradient loops seamlessly.
|
||||
|
||||
```css
|
||||
.bg {
|
||||
position: fixed; inset: 0; z-index: -1;
|
||||
background:
|
||||
radial-gradient(40% 50% at 20% 30%, #5b8cff55, transparent 60%),
|
||||
radial-gradient(45% 55% at 80% 20%, #b05bff55, transparent 60%),
|
||||
radial-gradient(50% 60% at 50% 80%, #2de1c255, transparent 60%),
|
||||
#0b0e1a;
|
||||
background-size: 200% 200%;
|
||||
animation: meshmove 24s ease-in-out infinite;
|
||||
}
|
||||
@keyframes meshmove {
|
||||
0%, 100% { background-position: 0% 0%, 100% 0%, 50% 100%; }
|
||||
50% { background-position: 30% 20%, 70% 30%, 60% 70%; }
|
||||
}
|
||||
@media (prefers-reduced-motion: reduce) {
|
||||
.bg { animation: none; }
|
||||
}
|
||||
```
|
||||
|
||||
The `0%` and `100%` keyframes are identical, so the loop has no seam.
|
||||
|
||||
### 2. Full-screen GLSL gradient + noise shader (Three.js)
|
||||
|
||||
A flowing aurora/gradient using value noise in a fragment shader on a full-screen plane. `uTime` advances each frame; to loop, feed it a wrapped time (section 4).
|
||||
|
||||
```js
|
||||
import * as THREE from 'three';
|
||||
|
||||
const canvas = document.querySelector('#bg');
|
||||
const renderer = new THREE.WebGLRenderer({canvas, antialias: true});
|
||||
renderer.setPixelRatio(Math.min(window.devicePixelRatio, 2)); // cap for perf
|
||||
const scene = new THREE.Scene();
|
||||
const camera = new THREE.OrthographicCamera(-1, 1, 1, -1, 0, 1);
|
||||
|
||||
const uniforms = {
|
||||
uTime: {value: 0},
|
||||
uRes: {value: new THREE.Vector2()},
|
||||
uColorA: {value: new THREE.Color('#5b8cff')},
|
||||
uColorB: {value: new THREE.Color('#b05bff')},
|
||||
};
|
||||
|
||||
const material = new THREE.ShaderMaterial({
|
||||
uniforms,
|
||||
vertexShader: `void main(){ gl_Position = vec4(position, 1.0); }`,
|
||||
fragmentShader: `
|
||||
precision highp float;
|
||||
uniform float uTime; uniform vec2 uRes;
|
||||
uniform vec3 uColorA, uColorB;
|
||||
|
||||
// hash + value noise
|
||||
float hash(vec2 p){ return fract(sin(dot(p, vec2(127.1,311.7)))*43758.5453); }
|
||||
float noise(vec2 p){
|
||||
vec2 i = floor(p), f = fract(p);
|
||||
float a = hash(i), b = hash(i+vec2(1,0));
|
||||
float c = hash(i+vec2(0,1)), d = hash(i+vec2(1,1));
|
||||
vec2 u = f*f*(3.0-2.0*f);
|
||||
return mix(mix(a,b,u.x), mix(c,d,u.x), u.y);
|
||||
}
|
||||
float fbm(vec2 p){
|
||||
float v=0.0, a=0.5;
|
||||
for(int i=0;i<5;i++){ v += a*noise(p); p*=2.0; a*=0.5; }
|
||||
return v;
|
||||
}
|
||||
void main(){
|
||||
vec2 uv = gl_FragCoord.xy / uRes.xy;
|
||||
float n = fbm(uv*3.0 + vec2(uTime*0.05, uTime*0.03));
|
||||
vec3 col = mix(uColorA, uColorB, smoothstep(0.2, 0.8, n + uv.y*0.3));
|
||||
gl_FragColor = vec4(col, 1.0);
|
||||
}`,
|
||||
});
|
||||
|
||||
const quad = new THREE.Mesh(new THREE.PlaneGeometry(2, 2), material);
|
||||
scene.add(quad);
|
||||
|
||||
function resize(){
|
||||
renderer.setSize(window.innerWidth, window.innerHeight);
|
||||
uniforms.uRes.value.set(window.innerWidth, window.innerHeight);
|
||||
}
|
||||
window.addEventListener('resize', resize); resize();
|
||||
|
||||
const clock = new THREE.Clock();
|
||||
let running = true;
|
||||
function loop(){
|
||||
if (running){
|
||||
uniforms.uTime.value = clock.getElapsedTime();
|
||||
renderer.render(scene, camera);
|
||||
}
|
||||
requestAnimationFrame(loop);
|
||||
}
|
||||
loop();
|
||||
```
|
||||
|
||||
### 3. Canvas constellation particles
|
||||
|
||||
Drifting points connected by lines when near — the classic "network" background. Pure canvas 2D, no dependencies.
|
||||
|
||||
```js
|
||||
const canvas = document.querySelector('#stars');
|
||||
const ctx = canvas.getContext('2d');
|
||||
let W, H, pts;
|
||||
const COUNT = 80, LINK = 120;
|
||||
|
||||
function init(){
|
||||
W = canvas.width = innerWidth; H = canvas.height = innerHeight;
|
||||
pts = Array.from({length: COUNT}, () => ({
|
||||
x: Math.random()*W, y: Math.random()*H,
|
||||
vx: (Math.random()-0.5)*0.3, vy: (Math.random()-0.5)*0.3,
|
||||
}));
|
||||
}
|
||||
addEventListener('resize', init); init();
|
||||
|
||||
function frame(){
|
||||
ctx.clearRect(0, 0, W, H);
|
||||
for (const p of pts){
|
||||
p.x += p.vx; p.y += p.vy;
|
||||
if (p.x<0||p.x>W) p.vx*=-1;
|
||||
if (p.y<0||p.y>H) p.vy*=-1;
|
||||
ctx.fillStyle = '#9db4ff'; ctx.fillRect(p.x, p.y, 2, 2);
|
||||
}
|
||||
for (let i=0;i<COUNT;i++) for (let j=i+1;j<COUNT;j++){
|
||||
const dx=pts[i].x-pts[j].x, dy=pts[i].y-pts[j].y;
|
||||
const d=Math.hypot(dx, dy);
|
||||
if (d<LINK){
|
||||
ctx.strokeStyle = `rgba(157,180,255,${1-d/LINK})`;
|
||||
ctx.beginPath(); ctx.moveTo(pts[i].x,pts[i].y); ctx.lineTo(pts[j].x,pts[j].y); ctx.stroke();
|
||||
}
|
||||
}
|
||||
requestAnimationFrame(frame);
|
||||
}
|
||||
frame();
|
||||
```
|
||||
|
||||
The O(n²) link loop is fine to ~120 points; above that, spatial-hash into a grid and only test neighboring cells.
|
||||
|
||||
### 4. Seamless loop technique
|
||||
|
||||
For canvas/JS, wrap time into a fixed period so motion repeats exactly. Use the loop *phase* (0→2π) as the argument to periodic functions:
|
||||
|
||||
```js
|
||||
const PERIOD = 12; // seconds
|
||||
const phase = (t % PERIOD) / PERIOD * Math.PI * 2;
|
||||
const offset = Math.sin(phase) * amp; // returns to start at t = PERIOD
|
||||
```
|
||||
|
||||
Any motion built only from `sin`/`cos` of `phase` (or integer multiples) loops seamlessly. In the shader, feed `uTime = phase` and use only `sin`/`cos` of it; for noise-scrolled gradients, scroll by an integer number of noise cells per period so the field tiles.
|
||||
|
||||
### 5. Reduced motion + offscreen/hidden pause
|
||||
|
||||
```js
|
||||
const reduce = matchMedia('(prefers-reduced-motion: reduce)').matches;
|
||||
if (reduce) {
|
||||
running = false; // render one static frame, then stop
|
||||
renderer.render(scene, camera);
|
||||
}
|
||||
|
||||
// Pause when the tab is hidden
|
||||
document.addEventListener('visibilitychange', () => {
|
||||
running = !document.hidden && !reduce;
|
||||
});
|
||||
|
||||
// Pause when the canvas scrolls offscreen
|
||||
new IntersectionObserver(([e]) => {
|
||||
running = e.isIntersecting && !document.hidden && !reduce;
|
||||
}).observe(canvas);
|
||||
```
|
||||
|
||||
When `running` is false, skip the render inside the rAF loop (as in section 2) — the loop stays alive to resume cheaply, but does no GPU/CPU work.
|
||||
|
||||
## Deliver & verify (standalone HTML)
|
||||
|
||||
> **Packaged helper** (`scripts/`): `scripts/seek-shot.sh anim.html 0 1.5 3` freezes the `?t=N` harness and screenshots each moment; `scripts/contact-sheet.sh sheet.png frame-*.png` tiles them for one-glance review. See `scripts/README.md`.
|
||||
|
||||
A motion background ships as **one `.html` file that opens directly in a browser** — markup, the background, and (for shader/canvas) Three.js or canvas JS from CDN, all inline. One file is the right tier.
|
||||
|
||||
**Output contract:**
|
||||
- One `.html` file: the background layer + a sample of foreground text on top to check readability/contrast.
|
||||
- One animation driver — the CSS `@keyframes`, the shader rAF loop, or the canvas rAF loop; just one.
|
||||
- Include the freeze harness below, matched to the technique, so any moment can be screenshotted deterministically.
|
||||
|
||||
**Freeze harness — pin a frame for screenshots.** Match the mechanism to the technique:
|
||||
|
||||
```html
|
||||
<script>
|
||||
const t = new URLSearchParams(location.search).get("t");
|
||||
if (t !== null) {
|
||||
const T = parseFloat(t);
|
||||
// CSS mesh gradient:
|
||||
document.querySelectorAll(".bg").forEach(el => {
|
||||
el.style.animationDelay = (-T) + "s";
|
||||
el.style.animationPlayState = "paused";
|
||||
});
|
||||
// GLSL shader instead? → render exactly one frame at fixed time:
|
||||
// uniforms.uTime.value = T; renderer.render(scene, camera); running = false;
|
||||
// Canvas particles? → seed deterministically, step the sim to T, draw once, stop the loop.
|
||||
}
|
||||
window.__ready = true; // ready signal for headless wait
|
||||
</script>
|
||||
```
|
||||
|
||||
**Verify loop — render → freeze → screenshot → check:**
|
||||
1. Open the file frozen at start / mid / end across one loop period: `…/bg.html?t=0`, `?t=<period/2>`, `?t=<period>`.
|
||||
2. Screenshot each frozen frame.
|
||||
3. Check **fidelity** (subtle, on-brand, seamless) and **artifacts** — text contrast holds at every frame, no banding in gradients/shader, the loop seam (`t=0` vs `t=period`) matches, no GPU/console errors.
|
||||
|
||||
```bash
|
||||
npx playwright screenshot --wait-for-timeout=600 "file://$PWD/bg.html?t=12" frame-mid.png
|
||||
```
|
||||
|
||||
**Before you finish:**
|
||||
1. Opens standalone in a browser — no console/WebGL errors, no missing CDN.
|
||||
2. One driver; `?t=N` freezes the exact frame (shader renders one frame, canvas sim stepped deterministically).
|
||||
3. Screenshotted at start / mid / end — foreground text stays readable, no banding, loop seam invisible.
|
||||
4. `prefers-reduced-motion` honored (one static frame rendered, loop stopped) + pauses offscreen/hidden.
|
||||
5. `devicePixelRatio` capped at 2; motion is slow and subtle, never out-contrasting content.
|
||||
|
||||
## Quick reference
|
||||
|
||||
| Need | Do |
|
||||
|---|---|
|
||||
| Cheapest gradient | CSS layered `radial-gradient` + `background-position` keyframes |
|
||||
| Organic flow | GLSL `fbm` noise, scroll `uTime` |
|
||||
| Network/dots | canvas particles + distance-linked lines |
|
||||
| No seam | drive motion by `sin/cos(phase)`, identical first/last keyframe |
|
||||
| Perf cap | `setPixelRatio(min(dpr, 2))`, throttle, reduce particle count on mobile |
|
||||
| Accessibility | `prefers-reduced-motion` static fallback |
|
||||
| Save battery | pause on `visibilitychange` + `IntersectionObserver` |
|
||||
|
||||
## Gotchas
|
||||
|
||||
- Never let the background out-contrast the foreground text — add a scrim if it does.
|
||||
- Uncapped `devicePixelRatio` on retina/4K murders the GPU; cap at 2.
|
||||
- `background-position` loops only if first and last keyframes match exactly.
|
||||
- Noise-scrolled shaders loop only if the scroll is an integer number of cells per period; otherwise the loop visibly jumps.
|
||||
- Forgetting the offscreen/hidden pause drains battery on mobile even when the user can't see it.
|
||||
|
||||
## Reference files
|
||||
|
||||
- `references/background-recipes.md` — fuller drop-in implementations: a richer multi-blob CSS mesh with blur, the complete Three.js aurora shader with mouse parallax and a true seamless-loop time wrap, a grid-optimized constellation field with mouse repulsion, a perfectly-looping noise-flow technique, and a complete reduced-motion + offscreen-pause manager wrapping all of them.
|
||||
@@ -0,0 +1,233 @@
|
||||
# Background Recipes — Drop-in Implementations
|
||||
|
||||
Fuller, production-ready versions of each technique. All are self-contained (Three.js is the only external dependency, and only for the shader recipe).
|
||||
|
||||
## 1. Rich CSS mesh gradient (blurred blobs)
|
||||
|
||||
Animated blobs behind a blur layer give a soft "mesh gradient" look without WebGL. Uses absolutely-positioned radial blobs and `filter: blur`.
|
||||
|
||||
```html
|
||||
<div class="mesh">
|
||||
<span class="blob b1"></span>
|
||||
<span class="blob b2"></span>
|
||||
<span class="blob b3"></span>
|
||||
</div>
|
||||
```
|
||||
|
||||
```css
|
||||
.mesh{ position:fixed; inset:0; z-index:-1; overflow:hidden; background:#0b0e1a; }
|
||||
.mesh .blob{
|
||||
position:absolute; width:50vmax; height:50vmax; border-radius:50%;
|
||||
filter:blur(80px); opacity:.55; mix-blend-mode:screen;
|
||||
}
|
||||
.b1{ background:#5b8cff; top:-10%; left:-5%; animation:drift1 26s ease-in-out infinite; }
|
||||
.b2{ background:#b05bff; top:30%; left:55%; animation:drift2 30s ease-in-out infinite; }
|
||||
.b3{ background:#2de1c2; top:60%; left:10%; animation:drift3 22s ease-in-out infinite; }
|
||||
|
||||
@keyframes drift1{ 0%,100%{transform:translate(0,0)} 50%{transform:translate(20vmax,10vmax)} }
|
||||
@keyframes drift2{ 0%,100%{transform:translate(0,0)} 50%{transform:translate(-18vmax,12vmax)} }
|
||||
@keyframes drift3{ 0%,100%{transform:translate(0,0)} 50%{transform:translate(12vmax,-14vmax)} }
|
||||
|
||||
@media (prefers-reduced-motion: reduce){ .mesh .blob{ animation:none } }
|
||||
```
|
||||
|
||||
`mix-blend-mode: screen` blends overlapping blobs into bright color fields; `blur` smooths them into a continuous mesh. Identical 0%/100% keyframes guarantee a seamless loop.
|
||||
|
||||
## 2. Three.js aurora shader — full, with parallax and seamless loop
|
||||
|
||||
```js
|
||||
import * as THREE from 'three';
|
||||
|
||||
export function createAurora(canvas){
|
||||
const renderer = new THREE.WebGLRenderer({canvas, antialias:true});
|
||||
renderer.setPixelRatio(Math.min(window.devicePixelRatio, 2));
|
||||
const scene = new THREE.Scene();
|
||||
const camera = new THREE.OrthographicCamera(-1,1,1,-1,0,1);
|
||||
|
||||
const PERIOD = 18.0; // seconds for a full seamless loop
|
||||
const u = {
|
||||
uPhase: {value:0}, // 0..2π, wraps each PERIOD
|
||||
uRes: {value:new THREE.Vector2()},
|
||||
uMouse: {value:new THREE.Vector2(0.5,0.5)},
|
||||
uColorA: {value:new THREE.Color('#0b1d4d')},
|
||||
uColorB: {value:new THREE.Color('#5b8cff')},
|
||||
uColorC: {value:new THREE.Color('#b05bff')},
|
||||
};
|
||||
|
||||
const material = new THREE.ShaderMaterial({
|
||||
uniforms:u,
|
||||
vertexShader:`void main(){ gl_Position=vec4(position,1.0); }`,
|
||||
fragmentShader:`
|
||||
precision highp float;
|
||||
uniform float uPhase; uniform vec2 uRes, uMouse;
|
||||
uniform vec3 uColorA, uColorB, uColorC;
|
||||
|
||||
float hash(vec2 p){ return fract(sin(dot(p,vec2(127.1,311.7)))*43758.5453); }
|
||||
float noise(vec2 p){
|
||||
vec2 i=floor(p), f=fract(p);
|
||||
float a=hash(i), b=hash(i+vec2(1,0)), c=hash(i+vec2(0,1)), d=hash(i+vec2(1,1));
|
||||
vec2 w=f*f*(3.0-2.0*f);
|
||||
return mix(mix(a,b,w.x), mix(c,d,w.x), w.y);
|
||||
}
|
||||
float fbm(vec2 p){ float v=0.,a=.5; for(int i=0;i<6;i++){v+=a*noise(p);p*=2.;a*=.5;} return v; }
|
||||
|
||||
void main(){
|
||||
vec2 uv = gl_FragCoord.xy/uRes.xy;
|
||||
uv += (uMouse-0.5)*0.06; // subtle parallax
|
||||
// loop the flow by moving along a circle in noise space:
|
||||
vec2 flow = vec2(cos(uPhase), sin(uPhase))*0.6;
|
||||
float n = fbm(uv*3.0 + flow);
|
||||
float bands = sin((uv.y*4.0 + n*2.0)) * 0.5 + 0.5;
|
||||
vec3 col = mix(uColorA, uColorB, smoothstep(0.2,0.7,n));
|
||||
col = mix(col, uColorC, smoothstep(0.5,1.0,bands)*0.6);
|
||||
gl_FragColor = vec4(col, 1.0);
|
||||
}`,
|
||||
});
|
||||
|
||||
const quad = new THREE.Mesh(new THREE.PlaneGeometry(2,2), material);
|
||||
scene.add(quad);
|
||||
|
||||
function resize(){
|
||||
renderer.setSize(innerWidth, innerHeight);
|
||||
u.uRes.value.set(innerWidth, innerHeight);
|
||||
}
|
||||
addEventListener('resize', resize); resize();
|
||||
addEventListener('pointermove', e => {
|
||||
u.uMouse.value.set(e.clientX/innerWidth, 1 - e.clientY/innerHeight);
|
||||
});
|
||||
|
||||
const start = performance.now();
|
||||
let running = true;
|
||||
function loop(){
|
||||
if (running){
|
||||
const t = (performance.now() - start)/1000;
|
||||
u.uPhase.value = (t % PERIOD)/PERIOD * Math.PI * 2; // wraps → seamless
|
||||
renderer.render(scene, camera);
|
||||
}
|
||||
requestAnimationFrame(loop);
|
||||
}
|
||||
loop();
|
||||
return {
|
||||
set running(v){ running = v; if (v) loop(); },
|
||||
renderOnce(){ renderer.render(scene, camera); },
|
||||
};
|
||||
}
|
||||
```
|
||||
|
||||
The seamless loop trick: drive the noise offset with `vec2(cos(uPhase), sin(uPhase))`, a closed circle in noise space — at `uPhase = 2π` the field is identical to `uPhase = 0`.
|
||||
|
||||
## 3. Constellation field — grid-optimized + mouse repulsion
|
||||
|
||||
```js
|
||||
export function createConstellation(canvas, {count=120, link=130, repel=140} = {}){
|
||||
const ctx = canvas.getContext('2d');
|
||||
let W,H,pts; const mouse = {x:-9999, y:-9999};
|
||||
|
||||
function init(){
|
||||
W = canvas.width = innerWidth; H = canvas.height = innerHeight;
|
||||
pts = Array.from({length:count}, () => ({
|
||||
x:Math.random()*W, y:Math.random()*H,
|
||||
vx:(Math.random()-0.5)*0.25, vy:(Math.random()-0.5)*0.25,
|
||||
}));
|
||||
}
|
||||
addEventListener('resize', init); init();
|
||||
addEventListener('pointermove', e => { mouse.x=e.clientX; mouse.y=e.clientY; });
|
||||
addEventListener('pointerleave', () => { mouse.x=mouse.y=-9999; });
|
||||
|
||||
// spatial hash to avoid O(n^2)
|
||||
const cell = link;
|
||||
function key(x,y){ return ((x/cell)|0)+','+((y/cell)|0); }
|
||||
|
||||
let running = true;
|
||||
function frame(){
|
||||
if (!running){ requestAnimationFrame(frame); return; }
|
||||
ctx.clearRect(0,0,W,H);
|
||||
const grid = new Map();
|
||||
for (const p of pts){
|
||||
p.x+=p.vx; p.y+=p.vy;
|
||||
if (p.x<0||p.x>W) p.vx*=-1;
|
||||
if (p.y<0||p.y>H) p.vy*=-1;
|
||||
// mouse repulsion
|
||||
const dx=p.x-mouse.x, dy=p.y-mouse.y, d=Math.hypot(dx,dy);
|
||||
if (d<repel){ p.x+=dx/d*1.5; p.y+=dy/d*1.5; }
|
||||
const k=key(p.x,p.y); (grid.get(k)||grid.set(k,[]).get(k)).push(p);
|
||||
ctx.fillStyle='#9db4ff'; ctx.fillRect(p.x,p.y,2,2);
|
||||
}
|
||||
// link only within neighboring cells
|
||||
for (const p of pts){
|
||||
const cx=(p.x/cell)|0, cy=(p.y/cell)|0;
|
||||
for (let gx=cx-1;gx<=cx+1;gx++) for (let gy=cy-1;gy<=cy+1;gy++){
|
||||
const bucket = grid.get(gx+','+gy); if (!bucket) continue;
|
||||
for (const q of bucket){
|
||||
if (q===p) continue;
|
||||
const dx=p.x-q.x, dy=p.y-q.y, d=Math.hypot(dx,dy);
|
||||
if (d<link){
|
||||
ctx.strokeStyle=`rgba(157,180,255,${(1-d/link)*0.6})`;
|
||||
ctx.beginPath(); ctx.moveTo(p.x,p.y); ctx.lineTo(q.x,q.y); ctx.stroke();
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
requestAnimationFrame(frame);
|
||||
}
|
||||
frame();
|
||||
return { set running(v){ running=v; } };
|
||||
}
|
||||
```
|
||||
|
||||
Spatial hashing keeps the link test near O(n) and scales to several hundred points.
|
||||
|
||||
## 4. Perfectly looping noise flow (canvas)
|
||||
|
||||
To loop drifting noise, sample it at a position that travels a closed path:
|
||||
|
||||
```js
|
||||
const PERIOD = 10; // seconds
|
||||
const phase = (t % PERIOD)/PERIOD * Math.PI*2;
|
||||
const sx = Math.cos(phase)*R; // closed circle → returns to start
|
||||
const sy = Math.sin(phase)*R;
|
||||
// feed (baseX + sx, baseY + sy) into your noise function
|
||||
```
|
||||
|
||||
Because `(sx,sy)` returns exactly to its start at `t = PERIOD`, the whole field repeats with no jump. For 1-D scroll loops instead, advance by an *integer* number of noise cells per period (`scroll = floor(cells) * (t % PERIOD)/PERIOD`) so the tile aligns.
|
||||
|
||||
## 5. Reduced-motion + lifecycle manager
|
||||
|
||||
A single controller that wraps any of the above (anything exposing a `running` setter and a one-frame render).
|
||||
|
||||
```js
|
||||
export function attachLifecycle(canvas, controller){
|
||||
const mq = matchMedia('(prefers-reduced-motion: reduce)');
|
||||
|
||||
function apply(){
|
||||
const reduced = mq.matches;
|
||||
if (reduced){
|
||||
controller.running = false;
|
||||
controller.renderOnce?.(); // one static frame
|
||||
return;
|
||||
}
|
||||
controller.running = !document.hidden && visible;
|
||||
}
|
||||
|
||||
let visible = true;
|
||||
const io = new IntersectionObserver(([e]) => { visible = e.isIntersecting; apply(); });
|
||||
io.observe(canvas);
|
||||
document.addEventListener('visibilitychange', apply);
|
||||
mq.addEventListener?.('change', apply);
|
||||
apply();
|
||||
|
||||
return () => { io.disconnect(); document.removeEventListener('visibilitychange', apply); };
|
||||
}
|
||||
```
|
||||
|
||||
Usage:
|
||||
|
||||
```js
|
||||
const aurora = createAurora(document.querySelector('#bg'));
|
||||
attachLifecycle(document.querySelector('#bg'), aurora);
|
||||
```
|
||||
|
||||
This guarantees: a static frame for reduced-motion users, no CPU/GPU work when the tab is hidden or the canvas is scrolled out of view, and automatic resume when conditions change.
|
||||
|
||||
---
|
||||
Keep the loop seamless and the cost low and a background lives behind content. Built by **[iart.ai](https://iart.ai/?utm_source=github&utm_medium=readme&utm_campaign=motion-design-skills&utm_content=skill_footer&utm_term=motion-background)** — the AI motion agent for editable, on-brand motion graphics.
|
||||
@@ -1,218 +0,0 @@
|
||||
---
|
||||
name: page-transition-animation
|
||||
description: This skill should be used when the user asks to "animate page or route transitions", "add a page transition or crossfade between views", "animate route changes in Next.js App Router", "use the View Transitions API", "AnimatePresence exit doesn't fire on navigation", or "Framer Motion exit animation not working / exit animation before unmount in Next.js". Covers enter/exit page-transition animation with the View Transitions API and Framer Motion, for Next.js App Router and general SPA routing.
|
||||
version: 0.1.0
|
||||
---
|
||||
|
||||
# Page Transition Animation (Next.js App Router)
|
||||
|
||||
Implement page enter/exit transitions in the Next.js **App Router**, and fix the single most common failure: **Framer Motion `AnimatePresence` exit animations never fire on navigation**. The reason is structural — in the App Router, when navigating, Next.js unmounts the old route's content and mounts the new one almost immediately. `AnimatePresence` can only animate an exit if the *exiting element stays mounted* under a *persistent* `AnimatePresence` wrapper long enough to run the animation. Because the router swaps children out from under it, the exit is skipped. Two approaches solve this: a pathname-keyed `AnimatePresence` with the **FrozenRouter** pattern, or the **View Transitions API** (native / `next-view-transitions`).
|
||||
|
||||
## When to use
|
||||
|
||||
Use when adding animated page transitions in a Next.js App Router app, when a Framer Motion `exit` prop does nothing on route change, when an old page disappears instantly instead of animating out, when choosing between Framer Motion and the View Transitions API for Next.js, or when debugging why `AnimatePresence` won't animate between routes.
|
||||
|
||||
## Why exit doesn't fire (the core problem)
|
||||
|
||||
`AnimatePresence` detects removal of a *direct keyed child*. On App Router navigation:
|
||||
|
||||
1. The wrapper must persist across the navigation. If `AnimatePresence` lives in a component that itself unmounts, there is nothing left to run the exit.
|
||||
2. The child's `key` must change per route so AnimatePresence sees "old removed, new added".
|
||||
3. During the brief overlap, the *outgoing* subtree must still render its old content — but the App Router has already swapped the route context, so the outgoing tree would otherwise render the *new* page's data. This is what **FrozenRouter** fixes.
|
||||
|
||||
## Solution A: template.tsx + keyed AnimatePresence + FrozenRouter
|
||||
|
||||
`template.tsx` is the App Router's purpose-built hook for this: unlike `layout.tsx` (which persists), a **template remounts on every navigation**, giving each route a fresh instance — ideal for per-route enter animations. Combine it with a pathname-keyed `AnimatePresence` and FrozenRouter for clean exit + enter.
|
||||
|
||||
```tsx
|
||||
// app/template.tsx
|
||||
'use client';
|
||||
import { AnimatePresence } from 'framer-motion';
|
||||
import { usePathname } from 'next/navigation';
|
||||
import { FrozenRouter } from './frozen-router';
|
||||
import { PageTransition } from './page-transition';
|
||||
|
||||
export default function Template({ children }: { children: React.ReactNode }) {
|
||||
const pathname = usePathname();
|
||||
return (
|
||||
<AnimatePresence mode="wait" initial={false}>
|
||||
{/* key on pathname so AnimatePresence sees old removed / new added */}
|
||||
<PageTransition key={pathname}>
|
||||
{/* FrozenRouter keeps the OUTGOING tree rendering its old content
|
||||
while it animates out */}
|
||||
<FrozenRouter>{children}</FrozenRouter>
|
||||
</PageTransition>
|
||||
</AnimatePresence>
|
||||
);
|
||||
}
|
||||
```
|
||||
|
||||
```tsx
|
||||
// app/page-transition.tsx
|
||||
'use client';
|
||||
import { motion } from 'framer-motion';
|
||||
|
||||
export function PageTransition({ children }: { children: React.ReactNode }) {
|
||||
return (
|
||||
<motion.div
|
||||
initial={{ opacity: 0, y: 12 }}
|
||||
animate={{ opacity: 1, y: 0 }}
|
||||
exit={{ opacity: 0, y: -12 }}
|
||||
transition={{ duration: 0.3, ease: [0.22, 1, 0.36, 1] }}
|
||||
>
|
||||
{children}
|
||||
</motion.div>
|
||||
);
|
||||
}
|
||||
```
|
||||
|
||||
```tsx
|
||||
// app/frozen-router.tsx
|
||||
'use client';
|
||||
import { useContext, useRef } from 'react';
|
||||
import {
|
||||
LayoutRouterContext,
|
||||
} from 'next/dist/shared/lib/app-router-context.shared-runtime';
|
||||
|
||||
// Freezes the router context so the exiting page keeps rendering its
|
||||
// OWN content during the exit animation instead of the next route's.
|
||||
export function FrozenRouter({ children }: { children: React.ReactNode }) {
|
||||
const context = useContext(LayoutRouterContext ?? {});
|
||||
const frozen = useRef(context).current;
|
||||
|
||||
return (
|
||||
<LayoutRouterContext.Provider value={frozen}>
|
||||
{children}
|
||||
</LayoutRouterContext.Provider>
|
||||
);
|
||||
}
|
||||
```
|
||||
|
||||
How it fits together:
|
||||
|
||||
- `mode="wait"` makes AnimatePresence fully finish the exit before mounting the new page. (Use the default mode if enter/exit should overlap/crossfade.)
|
||||
- `initial={false}` skips the enter animation on first load (optional).
|
||||
- `key={pathname}` is what makes AnimatePresence treat each route as a distinct presence.
|
||||
- `FrozenRouter` snapshots `LayoutRouterContext` so the outgoing subtree renders the *previous* route's content throughout the exit, instead of flashing the new route's content. Without it, exit either skips or shows the wrong content.
|
||||
|
||||
Note: `LayoutRouterContext` is a Next.js internal; its import path can change between Next versions. If the import breaks after an upgrade, that path is the thing to update.
|
||||
|
||||
## Solution B: native View Transitions API
|
||||
|
||||
The View Transitions API animates between two DOM states with the browser capturing before/after snapshots — no per-element exit components.
|
||||
|
||||
```css
|
||||
/* globals.css */
|
||||
@view-transition { navigation: auto; } /* opt MPA-style in (where supported) */
|
||||
|
||||
::view-transition-old(root) { animation: fade 0.25s both reverse; }
|
||||
::view-transition-new(root) { animation: fade 0.25s both; }
|
||||
@keyframes fade { from { opacity: 0; } to { opacity: 1; } }
|
||||
```
|
||||
|
||||
For SPA-style App Router navigations, wrap the router update:
|
||||
|
||||
```ts
|
||||
if (document.startViewTransition) {
|
||||
document.startViewTransition(() => router.push(href));
|
||||
} else {
|
||||
router.push(href);
|
||||
}
|
||||
```
|
||||
|
||||
### next-view-transitions library
|
||||
|
||||
`next-view-transitions` integrates the View Transitions API with the App Router's client navigation so it works out of the box:
|
||||
|
||||
```tsx
|
||||
// app/layout.tsx
|
||||
import { ViewTransitions } from 'next-view-transitions';
|
||||
export default function RootLayout({ children }: { children: React.ReactNode }) {
|
||||
return (
|
||||
<ViewTransitions>
|
||||
<html lang="en"><body>{children}</body></html>
|
||||
</ViewTransitions>
|
||||
);
|
||||
}
|
||||
```
|
||||
|
||||
```tsx
|
||||
// use the library's Link instead of next/link
|
||||
import { Link } from 'next-view-transitions';
|
||||
<Link href="/about">About</Link>;
|
||||
```
|
||||
|
||||
Choose View Transitions for simple cross-page fades/morphs and shared-element transitions with minimal JS; choose Framer Motion when fine-grained, orchestrated, interruptible, or staggered exit animations are needed. View Transitions API browser support is still uneven, so provide a graceful fallback (the `if (document.startViewTransition)` guard).
|
||||
|
||||
## AnimatePresence debug checklist
|
||||
|
||||
When exit still won't fire, verify in order:
|
||||
|
||||
1. **Wrapper stays mounted.** `AnimatePresence` must live in something persistent — ideally `template.tsx`, or a layout-level client component — not inside the page that's unmounting.
|
||||
2. **Stable, changing key.** The animated child needs `key={pathname}` (or similar) so removal is detected. No key, or a key that doesn't change → no exit.
|
||||
3. **Direct motion descendant.** The element with the `exit` prop must be a `motion.*` component and a child of `AnimatePresence` (a non-motion wrapper in between can block detection).
|
||||
4. **`mode="wait"`** if old and new should not overlap; without it both render simultaneously and may jump.
|
||||
5. **FrozenRouter present** if the outgoing page flashes the new route's content during exit.
|
||||
6. **`'use client'`** on every file using AnimatePresence/usePathname/motion.
|
||||
7. **Single child at a time** under `mode="wait"` — AnimatePresence expects one keyed presence to swap.
|
||||
|
||||
## Deliver & verify (standalone HTML)
|
||||
|
||||
> **Packaged helper** (`scripts/`): `scripts/seek-shot.sh anim.html 0 1.5 3` freezes the `?t=N` harness and screenshots each moment; `scripts/contact-sheet.sh sheet.png frame-*.png` tiles them for one-glance review. See `scripts/README.md`.
|
||||
|
||||
The real target is a Next.js app, but to *prove the transition shape* (the enter/exit curve, direction, crossfade) you can ship **one HTML file that opens directly in a browser** — two stub "pages" you toggle, animated with `motion` from CDN or the native View Transitions API. One file is the right tier for validating motion before wiring the router; don't stand up Next just to eyeball a fade.
|
||||
|
||||
**Output contract:**
|
||||
- One `.html` file: two view stubs and a toggle, animated with either an inline `<script type="module">` importing `motion`/React from CDN, or `document.startViewTransition` + `::view-transition-*` CSS.
|
||||
- A way to freeze the **resolved end state** — a route transition is state-driven (which view, mid-swap), so screenshot the state, not a clock.
|
||||
|
||||
**Seek harness — pin a transition phase.** `?view=b` mounts the destination view (or `?phase=exit` to hold the outgoing tree mid-animation) so a screenshot lands on a settled phase:
|
||||
|
||||
```html
|
||||
<script>
|
||||
const p = new URLSearchParams(location.search);
|
||||
document.documentElement.dataset.view = p.get("view") || "a"; // CSS/React keys off this
|
||||
// Framer Motion: set the controlled key/route from ?view; for mode="wait" the resolved end is the new page
|
||||
// View Transitions: screenshot the END state (snapshots are transient); or pause via emulate slow animations
|
||||
window.__ready = true;
|
||||
</script>
|
||||
```
|
||||
|
||||
**Verify loop — render → set phase → screenshot → check:** open source, mid, and destination (`?view=a`, `?phase=exit`, `?view=b`), screenshot each, and check **fidelity** (exit actually runs, direction/crossfade matches the brief, no `mode="wait"` lag) plus **artifacts** (outgoing tree flashing the new page's content, double-mount, FOUC, jank). Any headless tool works:
|
||||
|
||||
```bash
|
||||
npx playwright screenshot --wait-for-timeout=500 "file://$PWD/transition.html?view=b" dest.png
|
||||
```
|
||||
|
||||
**Before you finish:**
|
||||
1. Opens standalone — no console errors, CDN `motion`/React (if used) resolves, `startViewTransition` guarded.
|
||||
2. The `?view=`/`?phase=` freeze lands a deterministic transition phase.
|
||||
3. Screenshotted at source / mid / destination — matches the brief, no content flash or skipped exit.
|
||||
4. `prefers-reduced-motion` honored — slide/translate dropped to a short crossfade.
|
||||
5. Easing is intentional — entrances ease-out, exits ease-in, durations ~0.2–0.4s (not laggy under `mode="wait"`).
|
||||
|
||||
## Quick reference
|
||||
|
||||
| Need | Approach |
|
||||
|---|---|
|
||||
| Per-route enter animation | `app/template.tsx` (remounts each nav) |
|
||||
| Exit animation on nav | keyed `AnimatePresence mode="wait"` + FrozenRouter |
|
||||
| Outgoing page shows old content | FrozenRouter (snapshot `LayoutRouterContext`) |
|
||||
| Detect route change | `usePathname()` as the `key` |
|
||||
| Simple cross-page fade/morph | View Transitions API / next-view-transitions |
|
||||
| Shared element transition | `view-transition-name` CSS |
|
||||
| Skip first-load animation | `initial={false}` |
|
||||
|
||||
## Gotchas
|
||||
|
||||
- `layout.tsx` persists and will NOT remount per route — use `template.tsx` for per-route enter animations.
|
||||
- Omitting FrozenRouter makes the exiting page render the *new* route's content mid-animation (visible flash) or skip exit entirely.
|
||||
- `LayoutRouterContext` import path is a Next internal; it may change across versions — first thing to fix after an upgrade.
|
||||
- Without `key={pathname}`, AnimatePresence sees the same child and never triggers exit.
|
||||
- `mode="wait"` waits for exit before enter; overusing it on slow exits makes navigation feel laggy — tune durations (~0.2-0.4s).
|
||||
- View Transitions API lacks full browser support; always guard `document.startViewTransition`.
|
||||
- Every transition file needs `'use client'`; server components can't use AnimatePresence/usePathname.
|
||||
|
||||
## Reference files
|
||||
|
||||
- `references/full-examples.md` — directional/slide transitions, shared-element View Transitions with `view-transition-name`, a non-`mode="wait"` crossfade variant, loading-state transitions with `loading.tsx`, and a complete working App Router folder layout.
|
||||
@@ -1,176 +0,0 @@
|
||||
# Full examples and variants
|
||||
|
||||
## Working folder layout
|
||||
|
||||
```
|
||||
app/
|
||||
layout.tsx # persistent shell (html/body, providers)
|
||||
template.tsx # remounts per route -> hosts AnimatePresence
|
||||
page-transition.tsx # motion wrapper (enter/exit variants)
|
||||
frozen-router.tsx # FrozenRouter (LayoutRouterContext snapshot)
|
||||
page.tsx # home
|
||||
about/page.tsx
|
||||
globals.css
|
||||
```
|
||||
|
||||
## Directional slide transitions
|
||||
|
||||
Track direction by comparing route depth or a route order map, then feed it to variants.
|
||||
|
||||
```tsx
|
||||
// app/page-transition.tsx
|
||||
'use client';
|
||||
import { motion } from 'framer-motion';
|
||||
import { usePathname } from 'next/navigation';
|
||||
import { useRef } from 'react';
|
||||
|
||||
const order = ['/', '/about', '/work', '/contact'];
|
||||
|
||||
export function PageTransition({ children }: { children: React.ReactNode }) {
|
||||
const pathname = usePathname();
|
||||
const prev = useRef(pathname);
|
||||
const dir =
|
||||
order.indexOf(pathname) > order.indexOf(prev.current) ? 1 : -1;
|
||||
prev.current = pathname;
|
||||
|
||||
return (
|
||||
<motion.div
|
||||
custom={dir}
|
||||
variants={{
|
||||
initial: (d: number) => ({ opacity: 0, x: 40 * d }),
|
||||
animate: { opacity: 1, x: 0 },
|
||||
exit: (d: number) => ({ opacity: 0, x: -40 * d }),
|
||||
}}
|
||||
initial="initial"
|
||||
animate="animate"
|
||||
exit="exit"
|
||||
transition={{ duration: 0.3, ease: [0.22, 1, 0.36, 1] }}
|
||||
>
|
||||
{children}
|
||||
</motion.div>
|
||||
);
|
||||
}
|
||||
```
|
||||
|
||||
## Crossfade variant (no mode="wait")
|
||||
|
||||
Omit `mode="wait"` so old and new overlap. Stack them absolutely to avoid layout jump.
|
||||
|
||||
```tsx
|
||||
// app/template.tsx
|
||||
'use client';
|
||||
import { AnimatePresence, motion } from 'framer-motion';
|
||||
import { usePathname } from 'next/navigation';
|
||||
import { FrozenRouter } from './frozen-router';
|
||||
|
||||
export default function Template({ children }: { children: React.ReactNode }) {
|
||||
const pathname = usePathname();
|
||||
return (
|
||||
<AnimatePresence initial={false}>
|
||||
<motion.div
|
||||
key={pathname}
|
||||
style={{ gridArea: '1 / 1' }} // overlap in a 1-cell grid parent
|
||||
initial={{ opacity: 0 }}
|
||||
animate={{ opacity: 1 }}
|
||||
exit={{ opacity: 0 }}
|
||||
transition={{ duration: 0.35 }}
|
||||
>
|
||||
<FrozenRouter>{children}</FrozenRouter>
|
||||
</motion.div>
|
||||
</AnimatePresence>
|
||||
);
|
||||
}
|
||||
```
|
||||
|
||||
Wrap the template output's parent in `display: grid` so both stacked children occupy `grid-area: 1 / 1`.
|
||||
|
||||
## Shared-element transition (View Transitions API)
|
||||
|
||||
Give the same logical element the same `view-transition-name` on both pages; the browser morphs between them.
|
||||
|
||||
```tsx
|
||||
// list page
|
||||
<img src={cover} style={{ viewTransitionName: `cover-${id}` }} />
|
||||
// detail page
|
||||
<img src={cover} style={{ viewTransitionName: `cover-${id}` }} />
|
||||
```
|
||||
|
||||
```css
|
||||
::view-transition-old(root),
|
||||
::view-transition-new(root) { animation-duration: 0.3s; }
|
||||
/* the named element animates automatically between its two positions */
|
||||
```
|
||||
|
||||
With `next-view-transitions`, use its `<Link>` and the morph happens on navigation. Each `view-transition-name` must be unique on the page at a time.
|
||||
|
||||
## loading.tsx + transitions
|
||||
|
||||
`loading.tsx` shows an instant Suspense fallback during server work. To animate it, make the fallback a motion component; it mounts/unmounts within the same template-driven AnimatePresence flow.
|
||||
|
||||
```tsx
|
||||
// app/work/loading.tsx
|
||||
'use client';
|
||||
import { motion } from 'framer-motion';
|
||||
export default function Loading() {
|
||||
return (
|
||||
<motion.div initial={{ opacity: 0 }} animate={{ opacity: 1 }}>
|
||||
Loading…
|
||||
</motion.div>
|
||||
);
|
||||
}
|
||||
```
|
||||
|
||||
## Reduced-motion
|
||||
|
||||
```tsx
|
||||
'use client';
|
||||
import { useReducedMotion, motion } from 'framer-motion';
|
||||
|
||||
export function PageTransition({ children }: { children: React.ReactNode }) {
|
||||
const reduce = useReducedMotion();
|
||||
return (
|
||||
<motion.div
|
||||
initial={reduce ? false : { opacity: 0, y: 12 }}
|
||||
animate={{ opacity: 1, y: 0 }}
|
||||
exit={reduce ? { opacity: 1 } : { opacity: 0, y: -12 }}
|
||||
transition={{ duration: reduce ? 0 : 0.3 }}
|
||||
>
|
||||
{children}
|
||||
</motion.div>
|
||||
);
|
||||
}
|
||||
```
|
||||
|
||||
For the View Transitions API, gate with CSS:
|
||||
|
||||
```css
|
||||
@media (prefers-reduced-motion: reduce) {
|
||||
::view-transition-old(root),
|
||||
::view-transition-new(root) { animation: none; }
|
||||
}
|
||||
```
|
||||
|
||||
## FrozenRouter import note across versions
|
||||
|
||||
The internal context import has shifted across Next versions, e.g.:
|
||||
|
||||
```ts
|
||||
// commonly:
|
||||
import { LayoutRouterContext } from 'next/dist/shared/lib/app-router-context.shared-runtime';
|
||||
```
|
||||
|
||||
If an upgrade breaks the import, search `node_modules/next/dist/shared/lib/` for `app-router-context` and update the path. Because it is internal, pin awareness of this in any upgrade checklist.
|
||||
|
||||
## Framer Motion vs View Transitions decision
|
||||
|
||||
| Factor | Framer Motion | View Transitions API |
|
||||
|---|---|---|
|
||||
| Browser support | Broad (JS lib) | Uneven; needs fallback |
|
||||
| Orchestration/stagger | Excellent | Limited |
|
||||
| Interruptible exits | Yes | Limited |
|
||||
| Shared element morph | Manual (layoutId) | Native, simple |
|
||||
| Bundle cost | Adds library | Minimal/native |
|
||||
| Setup complexity | Medium (FrozenRouter) | Low (next-view-transitions) |
|
||||
|
||||
---
|
||||
Freeze the outgoing route and exit transitions finally fire as intended. Built by **[iart.ai](https://iart.ai/?utm_source=github&utm_medium=readme&utm_campaign=web-animation-skills&utm_content=skill_footer&utm_term=page-transition-animation)** — the AI motion agent for editable, on-brand motion graphics.
|
||||
File renamed without changes.
@@ -0,0 +1,194 @@
|
||||
---
|
||||
name: remotion-video
|
||||
description: This skill should be used when the user asks to "make a video with Remotion", "create a programmatic/data-driven video in React", "render an MP4/GIF from code", "animate with useCurrentFrame/interpolate/spring", "sync video to audio/beats", or "render a templated video per record headlessly". Covers building React compositions and rendering them via CLI or @remotion/renderer.
|
||||
version: 0.1.0
|
||||
---
|
||||
|
||||
# Remotion (Programmatic Video)
|
||||
|
||||
Build real MP4/GIF/WebM videos in React. Every frame is a pure function of `useCurrentFrame()`, so output is deterministic, scrubbable, diffable, and renderable in CI. The code-first alternative to After Effects for templated and data-driven motion graphics.
|
||||
|
||||
## When to use
|
||||
|
||||
- Render MP4/GIF/WebM from code (social clips, title cards, explainers).
|
||||
- Templated/data-driven videos: one composition, many outputs from props (per-user, per-record, per-row of a CSV/DB).
|
||||
- Motion graphics that must be versioned, code-reviewed, and rendered in CI without a GUI.
|
||||
- Programmatic audio sync, charts that animate from data, or embedding shaders/Three.js into video.
|
||||
|
||||
## Core techniques
|
||||
|
||||
### Frame-driven animation
|
||||
|
||||
Animation is derived from the current frame, never from `setState` or `requestAnimationFrame`. `interpolate` maps an input range to an output range; `spring` produces physically natural motion.
|
||||
|
||||
```jsx
|
||||
import {useCurrentFrame, useVideoConfig, interpolate, spring} from 'remotion';
|
||||
|
||||
export const Title = () => {
|
||||
const frame = useCurrentFrame();
|
||||
const {fps} = useVideoConfig();
|
||||
|
||||
// Fade in over frames 0-30, then stay (clamp prevents over/undershoot).
|
||||
const opacity = interpolate(frame, [0, 30], [0, 1], {
|
||||
extrapolateLeft: 'clamp',
|
||||
extrapolateRight: 'clamp',
|
||||
});
|
||||
|
||||
// Spring entrance; divide by spring duration is unnecessary — drive transforms directly.
|
||||
const scale = spring({frame, fps, config: {damping: 200, mass: 1, stiffness: 100}});
|
||||
|
||||
return <h1 style={{opacity, transform: `scale(${scale})`}}>Hello</h1>;
|
||||
};
|
||||
```
|
||||
|
||||
Always clamp `interpolate` unless an intentional overshoot is desired — by default it extrapolates linearly past the range, which produces opacity > 1 or negative values.
|
||||
|
||||
### Scheduling: Sequence and Series
|
||||
|
||||
`<Sequence>` shifts time: children see `frame` reset to 0 at the sequence's `from`. Use it to place clips on a timeline. `<Series>` lays out back-to-back segments without manual offset math.
|
||||
|
||||
```jsx
|
||||
import {Sequence, Series, AbsoluteFill} from 'remotion';
|
||||
|
||||
export const Timeline = () => (
|
||||
<AbsoluteFill style={{backgroundColor: 'black'}}>
|
||||
<Sequence from={0} durationInFrames={60}><Intro /></Sequence>
|
||||
<Sequence from={60} durationInFrames={90}><Body /></Sequence>
|
||||
|
||||
{/* Series auto-sequences; offset overlaps the previous segment for crossfades */}
|
||||
<Series>
|
||||
<Series.Sequence durationInFrames={60}><ShotA /></Series.Sequence>
|
||||
<Series.Sequence durationInFrames={60} offset={-15}><ShotB /></Series.Sequence>
|
||||
</Series>
|
||||
</AbsoluteFill>
|
||||
);
|
||||
```
|
||||
|
||||
### Composition registration + parametric props
|
||||
|
||||
The `<Composition>` declares id, size, fps, duration, and `defaultProps`. A zod schema makes props type-safe and editable in the Studio sidebar.
|
||||
|
||||
```jsx
|
||||
import {Composition} from 'remotion';
|
||||
import {z} from 'zod';
|
||||
|
||||
export const schema = z.object({
|
||||
title: z.string(),
|
||||
accent: z.string(),
|
||||
fps: z.number().default(30),
|
||||
});
|
||||
|
||||
export const Root = () => (
|
||||
<Composition
|
||||
id="Promo"
|
||||
component={Promo}
|
||||
durationInFrames={150}
|
||||
fps={30}
|
||||
width={1080}
|
||||
height={1920}
|
||||
schema={schema}
|
||||
defaultProps={{title: 'Launch', accent: '#5b8cff', fps: 30}}
|
||||
/>
|
||||
);
|
||||
```
|
||||
|
||||
To make duration data-dependent, use `calculateMetadata` on the Composition to compute `durationInFrames` from props (e.g. number of rows × frames per row) before render.
|
||||
|
||||
### Audio and beat sync
|
||||
|
||||
```jsx
|
||||
import {Audio, staticFile, useCurrentFrame, useVideoConfig} from 'remotion';
|
||||
|
||||
const BEATS_SEC = [0.5, 1.0, 1.5, 2.0]; // detected offline
|
||||
export const Music = ({children}) => {
|
||||
const frame = useCurrentFrame();
|
||||
const {fps} = useVideoConfig();
|
||||
const t = frame / fps;
|
||||
const onBeat = BEATS_SEC.some((b) => Math.abs(t - b) < 1 / fps);
|
||||
return (
|
||||
<>
|
||||
<Audio src={staticFile('track.mp3')} />
|
||||
<div style={{transform: `scale(${onBeat ? 1.06 : 1})`}}>{children}</div>
|
||||
</>
|
||||
);
|
||||
};
|
||||
```
|
||||
|
||||
Detect beats offline (e.g. with `web-audio-beat-detector` or aubio) and bake the timestamps into props — never analyze audio at render time, since headless rendering has no realtime audio clock.
|
||||
|
||||
### Rendering
|
||||
|
||||
Preview in the browser-based Studio; render headlessly via CLI or the programmatic API.
|
||||
|
||||
```bash
|
||||
npx remotion studio # interactive preview
|
||||
npx remotion render Promo out/promo.mp4 \
|
||||
--props='{"title":"Launch","accent":"#f43"}' # pass parametric props
|
||||
npx remotion render Promo out.gif --codec=gif # GIF output
|
||||
```
|
||||
|
||||
For batch/data-driven pipelines, render in Node with `@remotion/renderer` (bundle once, render many) — see the reference file.
|
||||
|
||||
## Deliver & verify (rendered stills → MP4)
|
||||
|
||||
> **Packaged helper** (`scripts/`): tile your stills with `scripts/contact-sheet.sh sheet.png f-hook.png f-mid.png f-end.png`, then assert the encode with `scripts/probe-mp4.sh out.mp4 [WxH] [fps]`. See `scripts/README.md`.
|
||||
|
||||
Remotion is frame-deterministic by construction — every frame is a pure function of `useCurrentFrame()`, so you can render any exact frame headlessly with **no seek harness** (this is the heavy-tier counterpart to a web scene's `?t=N`). Use this tier when the output must be an MP4/GIF, must carry exact numbers/text, or batches from data; for a lightweight web animation, deliver standalone HTML instead.
|
||||
|
||||
**Output contract:**
|
||||
- A Remotion project with the composition registered (`<Composition>` + zod `schema` + `defaultProps`), all motion frame-driven (no timers / `Date.now()` / `Math.random()`).
|
||||
- Deliverable = the rendered `out/*.mp4` (plus the project, so the user can re-render with new props/data).
|
||||
- Duration data-dependent? compute it in `calculateMetadata`, not by hand.
|
||||
|
||||
**Verify loop — render stills → inspect → encode.** Render single frames first (cheap, no video encode), inspect them, and encode the full video only once the frames are right.
|
||||
|
||||
```bash
|
||||
# 1. Frame-exact stills at start / mid / end (PNG, headless, fast)
|
||||
npx remotion still Promo out/f-start.png --frame=0
|
||||
npx remotion still Promo out/f-mid.png --frame=75
|
||||
npx remotion still Promo out/f-end.png --frame=149 # last frame = durationInFrames - 1
|
||||
# render with the SAME props you'll ship, not just defaultProps:
|
||||
# npx remotion still Promo out/f-mid.png --frame=75 --props='{"title":"Launch"}'
|
||||
|
||||
# 2. Inspect each PNG — fidelity (matches brief; numbers/text correct) AND
|
||||
# artifacts (text overflow, off-canvas, clipped safe-area, missing font, wrong data binding).
|
||||
|
||||
# 3. Only after the stills check out, encode the video:
|
||||
npx remotion render Promo out/promo.mp4 --props='{"title":"Launch"}'
|
||||
```
|
||||
|
||||
- Use `npx remotion compositions` to read each composition's `durationInFrames`/`fps` and pick the end frame.
|
||||
- **Data-driven / batch**: verify ONE representative props set via stills *before* batch-rendering all rows — catch a layout bug once instead of N times.
|
||||
- **README demo GIF for free**: `npx remotion render Promo out/demo.gif --codec=gif` produces the first-screen proof clip (Direction D).
|
||||
|
||||
**Before you finish:**
|
||||
1. `npx remotion still` renders cleanly at frame 0, mid, and last — no errors, no missing assets/fonts.
|
||||
2. Numbers/text are exact and inside safe areas at every checked frame.
|
||||
3. Frame-driven only — no `Date.now()` / `Math.random()` / timers (determinism holds in CI).
|
||||
4. Props are zod-typed; the **shipped** props render correctly (not just `defaultProps`).
|
||||
5. Full MP4 encoded and plays; (optional) GIF rendered for the README.
|
||||
|
||||
## Quick reference
|
||||
|
||||
| Need | Use |
|
||||
|---|---|
|
||||
| Map time → value | `interpolate(frame, [a,b], [x,y], {extrapolateRight:'clamp'})` |
|
||||
| Natural easing | `spring({frame, fps, config})` |
|
||||
| Place a clip at t | `<Sequence from durationInFrames>` |
|
||||
| Back-to-back shots | `<Series>` |
|
||||
| Audio | `<Audio src={staticFile(...)} />` |
|
||||
| Frame ↔ seconds | `frame / fps` |
|
||||
| Loop a value | `frame % period` then interpolate |
|
||||
| Editable props | zod `schema` on `<Composition>` |
|
||||
| CI render | `npx remotion render` or `@remotion/renderer` |
|
||||
|
||||
## Gotchas
|
||||
|
||||
- Never use `Math.random()`, `Date.now()`, or animation timers — they break determinism. Use `random(seed)` from Remotion for stable per-frame randomness.
|
||||
- Load fonts and assets via `staticFile()` and wait with `delayRender`/`continueRender`, or fonts pop in mid-render.
|
||||
- Default `interpolate` extrapolates — clamp it.
|
||||
- `useCurrentFrame` inside a `<Sequence>` is local (starts at 0); use `useVideoConfig().durationInFrames` for absolute timing.
|
||||
|
||||
## Reference files
|
||||
|
||||
- `references/api-and-patterns.md` — `interpolate` options and `Easing`, spring config recipes, Sequence/Series scheduling, `<Audio>` + beat-sync, parametric `defaultProps` with zod + `calculateMetadata`, CLI flags, programmatic `@remotion/renderer` batch rendering, and embedding GLSL shaders / Three.js (`@remotion/three`).
|
||||
@@ -0,0 +1,224 @@
|
||||
# Remotion API & Patterns
|
||||
|
||||
Detailed cookbook for building and rendering Remotion compositions.
|
||||
|
||||
## interpolate: full options
|
||||
|
||||
```jsx
|
||||
import {interpolate, Easing} from 'remotion';
|
||||
|
||||
interpolate(frame, [0, 30, 60], [0, 100, 0], {
|
||||
easing: Easing.bezier(0.25, 0.1, 0.25, 1), // CSS ease equivalent
|
||||
extrapolateLeft: 'clamp', // 'extend' (default) | 'clamp' | 'identity' | 'wrap'
|
||||
extrapolateRight: 'clamp',
|
||||
});
|
||||
```
|
||||
|
||||
- Input ranges must be strictly monotonically increasing.
|
||||
- Multi-stop ranges (`[0,30,60]`) create keyframe chains.
|
||||
- `extrapolate: 'extend'` (default) continues the linear slope past the range — almost always clamp instead.
|
||||
- `extrapolate: 'wrap'` repeats the range — handy for loops.
|
||||
|
||||
Common easings: `Easing.linear`, `Easing.ease`, `Easing.in(Easing.quad)`, `Easing.out(Easing.cubic)`, `Easing.inOut(Easing.ease)`, `Easing.elastic(1)`, `Easing.bezier(x1,y1,x2,y2)`.
|
||||
|
||||
## spring: config recipes
|
||||
|
||||
```jsx
|
||||
spring({frame, fps, config, durationInFrames, delay, from, to});
|
||||
```
|
||||
|
||||
| Feel | config |
|
||||
|---|---|
|
||||
| Smooth, no overshoot | `{damping: 200}` |
|
||||
| Gentle bounce | `{damping: 12, stiffness: 100, mass: 1}` |
|
||||
| Snappy UI pop | `{damping: 20, stiffness: 200, mass: 0.6}` |
|
||||
| Heavy / slow | `{mass: 3, damping: 40, stiffness: 80}` |
|
||||
|
||||
- `from`/`to` remap the 0→1 output to any range without an extra `interpolate`.
|
||||
- `durationInFrames` time-stretches the spring to fit a fixed window.
|
||||
- `delay` postpones the start (in frames).
|
||||
- `measureSpring({fps, config})` returns how many frames the spring needs to settle — use it to size sequences.
|
||||
|
||||
```jsx
|
||||
// Spring from 100px down to 0, settling in 40 frames, starting at frame 10
|
||||
const y = spring({frame, fps, from: 100, to: 0, durationInFrames: 40, delay: 10});
|
||||
```
|
||||
|
||||
## Sequence & Series scheduling
|
||||
|
||||
```jsx
|
||||
<Sequence from={30} durationInFrames={60} name="Caption" layout="none">
|
||||
<Caption />
|
||||
</Sequence>
|
||||
```
|
||||
|
||||
- `from` offsets local time; inside, `useCurrentFrame()` returns `globalFrame - from`.
|
||||
- `durationInFrames` clips visibility; omit for infinite.
|
||||
- `layout="none"` removes the default absolute-fill wrapper (use when the child manages its own layout, e.g. inline text).
|
||||
- `name` labels the sequence in the Studio timeline.
|
||||
|
||||
Crossfade between two Series segments by overlapping with negative `offset` and fading:
|
||||
|
||||
```jsx
|
||||
<Series>
|
||||
<Series.Sequence durationInFrames={90}><Slide src="a.jpg" /></Series.Sequence>
|
||||
<Series.Sequence durationInFrames={90} offset={-20}>
|
||||
<Slide src="b.jpg" fadeInFrames={20} />
|
||||
</Series.Sequence>
|
||||
</Series>
|
||||
```
|
||||
|
||||
## Audio + beat sync
|
||||
|
||||
```jsx
|
||||
import {Audio, staticFile} from 'remotion';
|
||||
|
||||
<Audio
|
||||
src={staticFile('music.mp3')}
|
||||
startFrom={30} // trim: start 30 frames into the file
|
||||
endAt={300}
|
||||
volume={(f) => interpolate(f, [0, 30], [0, 1], {extrapolateRight: 'clamp'})} // fade-in
|
||||
/>
|
||||
```
|
||||
|
||||
Detect beats offline and store them as props:
|
||||
|
||||
```js
|
||||
// build step (Node) — produce beats.json
|
||||
import {guess} from 'web-audio-beat-detector';
|
||||
// ...decode audio buffer, then:
|
||||
const {bpm, offset} = await guess(audioBuffer);
|
||||
const period = 60 / bpm;
|
||||
const beats = Array.from({length: 64}, (_, i) => offset + i * period);
|
||||
```
|
||||
|
||||
Then in the component, snap motion to the nearest beat using `frame / fps`.
|
||||
|
||||
## Parametric defaultProps + zod + calculateMetadata
|
||||
|
||||
```jsx
|
||||
import {Composition} from 'remotion';
|
||||
import {z} from 'zod';
|
||||
import {zColor} from '@remotion/zod-types';
|
||||
|
||||
export const promoSchema = z.object({
|
||||
title: z.string(),
|
||||
rows: z.array(z.object({label: z.string(), value: z.number()})),
|
||||
accent: zColor(), // gives a color picker in the Studio
|
||||
});
|
||||
|
||||
export const Root = () => (
|
||||
<Composition
|
||||
id="DataPromo"
|
||||
component={DataPromo}
|
||||
fps={30}
|
||||
width={1080}
|
||||
height={1080}
|
||||
schema={promoSchema}
|
||||
defaultProps={{title: 'Q3', rows: [], accent: '#5b8cff'}}
|
||||
// Compute duration from data BEFORE rendering:
|
||||
calculateMetadata={({props}) => ({
|
||||
durationInFrames: 30 + props.rows.length * 20,
|
||||
})}
|
||||
/>
|
||||
);
|
||||
```
|
||||
|
||||
`zColor()` from `@remotion/zod-types` renders a color picker; plain `z.string()` renders a text field.
|
||||
|
||||
## CLI rendering
|
||||
|
||||
```bash
|
||||
# Render with inline props
|
||||
npx remotion render DataPromo out.mp4 --props='{"title":"Q3"}'
|
||||
|
||||
# Render from a props file (per-record batch)
|
||||
npx remotion render DataPromo out/$ID.mp4 --props=./data/$ID.json
|
||||
|
||||
# Quality / format flags
|
||||
npx remotion render Promo out.mp4 --codec=h264 --crf=18 --jpeg-quality=90
|
||||
npx remotion render Promo out.webm --codec=vp8
|
||||
npx remotion render Promo still.png --frame=45 # single still
|
||||
npx remotion render Promo out.gif --codec=gif --every-nth-frame=2
|
||||
|
||||
# Concurrency / scale
|
||||
npx remotion render Promo out.mp4 --concurrency=4 --scale=2
|
||||
```
|
||||
|
||||
## Programmatic render with @remotion/renderer
|
||||
|
||||
Bundle once, then render many outputs — the right pattern for data-driven pipelines.
|
||||
|
||||
```js
|
||||
import {bundle} from '@remotion/bundler';
|
||||
import {renderMedia, selectComposition} from '@remotion/renderer';
|
||||
import path from 'path';
|
||||
|
||||
const serveUrl = await bundle({entryPoint: path.resolve('src/index.ts')});
|
||||
|
||||
for (const record of records) {
|
||||
const composition = await selectComposition({
|
||||
serveUrl,
|
||||
id: 'DataPromo',
|
||||
inputProps: record, // drives calculateMetadata too
|
||||
});
|
||||
|
||||
await renderMedia({
|
||||
composition,
|
||||
serveUrl,
|
||||
codec: 'h264',
|
||||
outputLocation: `out/${record.id}.mp4`,
|
||||
inputProps: record,
|
||||
crf: 18,
|
||||
concurrency: 4,
|
||||
});
|
||||
}
|
||||
```
|
||||
|
||||
`selectComposition` resolves `calculateMetadata`, so per-record duration works automatically. Reusing one `serveUrl` across renders avoids re-bundling.
|
||||
|
||||
For stills, use `renderStill({composition, serveUrl, output, frame})`.
|
||||
|
||||
## Embedding shaders / Three.js
|
||||
|
||||
Use `@remotion/three` to drive a Three.js scene by frame:
|
||||
|
||||
```jsx
|
||||
import {ThreeCanvas, useVideoTexture} from '@remotion/three';
|
||||
import {useCurrentFrame, useVideoConfig} from 'remotion';
|
||||
|
||||
const Scene = () => {
|
||||
const frame = useCurrentFrame();
|
||||
return (
|
||||
<mesh rotation={[0, frame * 0.02, 0]}>
|
||||
<boxGeometry args={[2, 2, 2]} />
|
||||
<meshStandardMaterial color="#5b8cff" />
|
||||
</mesh>
|
||||
);
|
||||
};
|
||||
|
||||
export const ThreeComp = () => {
|
||||
const {width, height} = useVideoConfig();
|
||||
return (
|
||||
<ThreeCanvas width={width} height={height}>
|
||||
<ambientLight intensity={0.6} />
|
||||
<pointLight position={[10, 10, 10]} />
|
||||
<Scene />
|
||||
</ThreeCanvas>
|
||||
);
|
||||
};
|
||||
```
|
||||
|
||||
For a raw GLSL shader background, render a full-screen quad with a `shaderMaterial` whose `uTime` uniform is set to `frame / fps` each render (driven by `useFrame` in react-three-fiber). Because the canvas re-renders per Remotion frame, the shader is deterministic.
|
||||
|
||||
Heavy WebGL benefits from `--gl=angle` (or `swangle` for headless servers without a GPU) on the render command.
|
||||
|
||||
## Determinism checklist
|
||||
|
||||
- Replace `Math.random()` with `random('seed' + frame)` from `remotion`.
|
||||
- Wrap async asset loads with `delayRender()` / `continueRender(handle)`.
|
||||
- Preload fonts with `@remotion/google-fonts` or `delayRender` around `document.fonts.load`.
|
||||
- Avoid `Date.now()`, `performance.now()`, and real timers entirely.
|
||||
|
||||
---
|
||||
Drive every frame from props and Remotion renders video as code. Built by **[iart.ai](https://iart.ai/?utm_source=github&utm_medium=readme&utm_campaign=motion-design-skills&utm_content=skill_footer&utm_term=remotion-video)** — the AI motion agent for editable, on-brand motion graphics.
|
||||
File renamed without changes.
@@ -0,0 +1,185 @@
|
||||
---
|
||||
name: shot-composition
|
||||
description: This skill should be used when the user asks to "compose a frame", "set up a grid", "plan shot composition", "place the focal point", "decide where elements enter and exit", "add a parallax/camera move", "adapt a layout for 16:9 / 9:16 / 1:1", or "keep content inside safe areas". Covers grids, safe areas, focal hierarchy, and 2D/3D camera framing.
|
||||
version: 0.1.0
|
||||
---
|
||||
|
||||
# Shot Composition
|
||||
|
||||
Stage the frame and move the camera: grid systems, safe areas, focal hierarchy, negative space, parallax layering, and how layout guides the eye over time. Produces composition notes, layer structure (bg/mid/fg), and concrete camera-move plans with numbers.
|
||||
|
||||
## When to use
|
||||
|
||||
- Defining a frame's layout, focal point, and negative space.
|
||||
- Planning element enter/exit directions and motion paths.
|
||||
- Designing camera push/pull, pan, follow, and parallax moves.
|
||||
- Adapting one composition across 16:9, 9:16, and 1:1 with safe areas.
|
||||
|
||||
## Decision tree
|
||||
|
||||
```
|
||||
What are you staging?
|
||||
├─ A static frame's layout
|
||||
│ └─ set grid → place ONE focal point on a thirds power point
|
||||
│ → rank hierarchy (size>contrast>color>position) → reserve negative space
|
||||
├─ Where things enter / leave
|
||||
│ └─ follow reading direction; nearest edge; ease-out in, ease-in out
|
||||
│ (new content → from right/below; back/undo → reverse it)
|
||||
├─ A sense of depth / a camera move
|
||||
│ └─ split into bg/mid/fg layers (the three motion layers)
|
||||
│ → ONE camera move per beat (push | pan | follow | parallax), ease-in-out
|
||||
└─ One comp across aspects (16:9 / 9:16 / 1:1)
|
||||
└─ master in 16:9, focal in the center band → RESTACK (don't crop) for 9:16
|
||||
→ keep critical content inside title-safe margins
|
||||
```
|
||||
|
||||
**Cross-reference — apply the shared frameworks.** This skill is the spatial half of `animation-principles`. Apply them explicitly:
|
||||
|
||||
- **1/3 Rule** (`animation-principles`) has two forms and this skill uses both *spatially*: (a) *Composition thirds* — place the focal point on a rule-of-thirds power point (33%/67%); (b) *Distance* — no element travels more than ~1/3 of the frame without an intermediate keyframe or a scale/opacity change, so entrances stay readable.
|
||||
- **Three motion layers** (`animation-principles`: Primary / Secondary / Ambient) map directly onto depth: **foreground = Primary** (the move the eye follows), **midground = Secondary** (the subject + supporting reactions), **background = Ambient** (slow, low-contrast life). Parallax speed scales with that role.
|
||||
- Settle the **Three Pillars** (Emotional intent / Visual narrative / Motion craft) and the chosen **Motion Personality** (`motion-art-direction`) *before* numbering a camera move — premium wants slow long pushes, energetic wants whip-pans.
|
||||
|
||||
## Core workflow
|
||||
|
||||
### 1. Establish a grid
|
||||
|
||||
A grid gives alignment and rhythm. Default to a **12-column grid** for landscape web/video (it divides into halves, thirds, quarters, sixths) with gutters and outer margins. For a 1920px-wide frame: outer margin 80-120px, 12 columns, gutter 24-32px.
|
||||
|
||||
```
|
||||
content_width = frame_width - 2 * margin
|
||||
column_width = (content_width - (cols - 1) * gutter) / cols
|
||||
```
|
||||
|
||||
Example (1920 wide, margin 100, gutter 24, 12 cols): content 1720, column = (1720 - 11*24)/12 = 121.3px.
|
||||
|
||||
A **baseline grid** (vertical rhythm) of 8px is the standard spacing unit; size and space everything in multiples of 8 (8/16/24/32/48/64) for visual cohesion.
|
||||
|
||||
### 2. Place the focal point
|
||||
|
||||
Use the **rule of thirds**: divide the frame into a 3x3 grid; place the primary subject on a third-line or at an intersection (the "power points"), not dead center — unless the piece deliberately uses symmetry for stillness/formality. The intersections roughly fall at 33%/67% horizontally and vertically.
|
||||
|
||||
Build **visual hierarchy** in this priority order to direct the eye: **size > contrast > color > position**. The biggest, highest-contrast element wins attention first. Establish exactly one primary focal point per frame; secondary elements support, never compete.
|
||||
|
||||
### 3. Use negative space as rhythm
|
||||
|
||||
Do not fill the frame. Generous negative space around the focal point makes it read as premium and confident, and gives motion room to breathe. Whitespace is an active compositional element, not leftover.
|
||||
|
||||
### 4. Layer the scene (bg / mid / fg) for depth and parallax
|
||||
|
||||
Split the composition into depth layers: **background** (slowest, lowest contrast, often desaturated/blurred), **midground** (the subject), **foreground** (fastest, may blur as it crosses). Parallax = moving layers at different speeds to simulate depth.
|
||||
|
||||
These depth layers ARE the `animation-principles` **three motion layers** projected onto Z — each layer's role dictates its speed, contrast, and how much motion it earns:
|
||||
|
||||
| Depth | Motion layer | Parallax speed | Contrast / focus | What lives here |
|
||||
|---|---|---|---|---|
|
||||
| Background | Ambient | 0.1–0.3x | low, often desaturated/blurred | sky, gradient, texture, set dressing |
|
||||
| Midground | Secondary | 0.5–0.7x | mid; supports the subject | subject's environment, supporting elements |
|
||||
| Foreground | Primary | 1.0–1.5x | sharp on subject; FG props blur as they cross | the hero subject + closest props |
|
||||
|
||||
Foreground may exceed 1.0 to read as very close. The Primary move is the one the eye follows; never give two layers competing primary motion.
|
||||
|
||||
### 5. Camera language (works in 2D and 3D)
|
||||
|
||||
- **Push / pull** — scale into or away from the subject (dolly). Builds intimacy or reveals context. 800-2000ms, ease-in-out.
|
||||
- **Pan / tilt / move** — translate the frame across the scene. Reveals space, follows action.
|
||||
- **Follow** — keep a moving subject framed (often slightly off-center, leading the motion).
|
||||
- **Parallax** — layered move that sells depth.
|
||||
|
||||
**One shot, one intent.** Don't push + pan + rotate simultaneously — combined moves read as chaotic. Pick the single move that serves the beat. Inline timing essentials: camera moves use ease-in-out (`cubic-bezier(0.65, 0, 0.35, 1)`); never `linear` except continuous loops; slower is more cinematic.
|
||||
|
||||
### 6. Enter/exit direction carries meaning
|
||||
|
||||
Motion that follows reading direction (left-to-right, top-to-bottom in LTR locales) feels natural and smooth; reversing it creates tension or signals "back/undo." Match the direction to the intent:
|
||||
- New content arriving -> enter from the right / from below.
|
||||
- Dismissing / going back -> exit right or down, or reverse the entrance.
|
||||
- Drilling deeper -> scale up / push in.
|
||||
|
||||
Elements should usually enter and exit through the nearest frame edge with a slight overshoot on enter (ease-out) and acceleration on exit (ease-in).
|
||||
|
||||
### 7. Safe areas and multi-aspect adaptation
|
||||
|
||||
Keep all critical content (text, logos, faces, CTAs) inside a **title-safe margin** so nothing gets clipped or hidden behind platform UI.
|
||||
|
||||
| Aspect | Use | Title-safe margin | Notes |
|
||||
|---|---|---|---|
|
||||
| 16:9 | YouTube, web hero | ~5% all sides | broadcast title-safe historically 10% |
|
||||
| 9:16 | Reels, TikTok, Stories | top ~12-14%, bottom ~18-20%, sides ~6% | platform UI eats top and bottom |
|
||||
| 1:1 | feed posts | ~6-8% all sides | symmetric |
|
||||
| 4:5 | feed (taller) | ~6% sides, ~8% top/bottom | maximizes feed real estate |
|
||||
|
||||
Design the **focal point centered enough** that it survives all crops, then let secondary elements reflow per aspect. For 16:9 -> 9:16, restack horizontal arrangements vertically rather than just cropping the sides off.
|
||||
|
||||
## Worked examples
|
||||
|
||||
### GOOD — product hero, 16:9 → 9:16
|
||||
|
||||
> **Brief**: app launch hero, Premium personality, must work as a web hero and a Reel.
|
||||
>
|
||||
> - **Grid**: 1920×1080, margin 100, gutter 24, 12 cols. Phone mockup spans cols 7–11 (right power-column).
|
||||
> - **Focal**: phone screen on the right thirds intersection (1280, 360) — not centered. One focal point; the headline (cols 1–5) is secondary, lower contrast.
|
||||
> - **Depth (three motion layers)**: bg = soft gradient drift, 0.2x, Ambient. mid = phone mockup, 0.6x, Secondary stage. fg = one out-of-focus UI chip drifting past, 1.2x + 3px blur, reads as Primary depth cue.
|
||||
> - **Camera**: single push-in, scale 1.0→1.10 over 1600ms ease-in-out, origin on the phone screen — matches Premium (slow, no overshoot). No pan added.
|
||||
> - **9:16 adapt**: restack — headline moves *above* the phone, phone pulled up to the upper-middle to clear the bottom 19% CTA/nav zone, type +20%. Focal survives the crop because it started in the center band.
|
||||
>
|
||||
> Why it works: one focal point, depth roles assigned, one camera move, safe-area-aware reflow instead of a blind crop.
|
||||
|
||||
### ANTI-PATTERN — the "everything centered, everything moving" frame
|
||||
|
||||
> - Phone mockup dead-center, headline centered above, logo centered below → three elements fighting on the same axis, no hierarchy, no power point.
|
||||
> - All three layers slide left at the same 1.0x speed → no parallax, no depth, reads as "the whole template moved" (violates the **1/3 Rule / distance**: a full-width slide with no intermediate keyframe).
|
||||
> - Camera does push + pan + slight rotate at once → chaotic, no single intent.
|
||||
> - 9:16 made by cropping the 16:9 sides → headline and logo clipped, phone too low behind the nav bar.
|
||||
>
|
||||
> Fix: pick one focal power point, assign each layer a depth role + distinct parallax speed, one camera move, and restack for vertical instead of cropping.
|
||||
|
||||
## Common mistakes
|
||||
|
||||
| Symptom | Why | Fix |
|
||||
|---|---|---|
|
||||
| Frame feels flat / "the template moved" | all layers move at one speed; no depth roles | assign bg/mid/fg the Ambient/Secondary/Primary roles + 0.2/0.6/1.2x parallax |
|
||||
| Eye doesn't know where to look | 2+ elements at equal size/contrast, all centered | one focal point on a thirds power point; rank size>contrast>color>position |
|
||||
| Camera move reads as chaotic | push + pan + rotate combined | one move per beat; pick the one that serves the intent |
|
||||
| Content clipped on phones | designed for 16:9, cropped to 9:16 | restack vertically; keep critical content in title-safe margins (top 13% / bottom 19% on 9:16) |
|
||||
| Entrance reads as "slide", not "event" | element travels >1/3 of frame in one unbroken move | break with an intermediate keyframe or pair travel with scale/opacity (1/3 Rule, distance) |
|
||||
| Looks cheap / cramped | frame filled edge to edge | reserve negative space around the focal point; it's an active element |
|
||||
| Motion fights the story | numbers chosen before intent | settle Three Pillars + Motion Personality first, then number the move |
|
||||
|
||||
## Deliverable — a composition plan
|
||||
|
||||
A good composition plan is handed to an implementation skill (`gsap-web`, `remotion-video`, `after-effects`) and contains:
|
||||
|
||||
- **Frame spec**: aspect(s), resolution, fps, grid (cols / margin / gutter), baseline unit.
|
||||
- **Focal point**: coordinates (px or %) on a thirds power point + the hierarchy ranking of every element.
|
||||
- **Layer map**: each element assigned bg/mid/fg → Ambient/Secondary/Primary, with parallax speed.
|
||||
- **Enter/exit**: per element — edge, direction, easing family, and whether travel exceeds 1/3 (and how it's broken).
|
||||
- **Camera move**: the single move, its property + from→to values, duration, easing, transform-origin.
|
||||
- **Safe areas**: title-safe margins per target aspect + the restack plan for vertical.
|
||||
- **Cross-refs**: which Motion Personality and which Pillars decisions drive the timing.
|
||||
|
||||
### Before you finish — checklist
|
||||
|
||||
- [ ] Exactly one primary focal point, on a thirds power point (or deliberate symmetry).
|
||||
- [ ] Hierarchy ranked (size > contrast > color > position); secondaries don't compete.
|
||||
- [ ] Negative space reserved around the focal point.
|
||||
- [ ] Every element assigned a depth layer (bg/mid/fg = Ambient/Secondary/Primary) with a parallax speed.
|
||||
- [ ] One camera move, not stacked; eased (not linear unless a loop); 800–2000ms for hero moves.
|
||||
- [ ] Entrances/exits use nearest edge, follow reading direction, ease-out in / ease-in out.
|
||||
- [ ] No element travels >1/3 of frame without an intermediate keyframe or scale/opacity change.
|
||||
- [ ] Critical content inside title-safe margins for every target aspect; vertical is restacked, not cropped.
|
||||
- [ ] Motion Personality + Three Pillars settled before any number was chosen.
|
||||
|
||||
## Quick reference
|
||||
|
||||
| Need | Default |
|
||||
|---|---|
|
||||
| Grid | 12 columns, 8px baseline, multiples of 8 spacing |
|
||||
| Focal placement | rule-of-thirds power point, not dead center |
|
||||
| Hierarchy order | size > contrast > color > position |
|
||||
| Depth layers | bg / mid / fg, parallax 0.2x / 0.6x / 1.2x |
|
||||
| Camera | one move at a time, ease-in-out, 800-2000ms |
|
||||
| Enter / exit | follow reading direction; ease-out in, ease-in out |
|
||||
| 9:16 safe | top 12%, bottom 18%, sides 6% |
|
||||
|
||||
## Reference files
|
||||
|
||||
- `references/camera-and-grids.md` — grid math with worked numbers, full safe-area percentage tables per aspect, parallax layering code (CSS scroll + JS pointer + Three.js), and named camera-move recipes (push-in, whip-pan, orbit, dolly-zoom) with keyframe values.
|
||||
@@ -0,0 +1,153 @@
|
||||
# Camera moves, grids, safe areas, and parallax
|
||||
|
||||
Worked math and runnable code. Camera timings use ease-in-out (`cubic-bezier(0.65, 0, 0.35, 1)`); never `linear` except continuous loops.
|
||||
|
||||
## Grid math
|
||||
|
||||
```
|
||||
content_width = frame_width - 2 * margin
|
||||
column_width = (content_width - (cols - 1) * gutter) / cols
|
||||
column_x(i) = margin + i * (column_width + gutter) // 0-indexed
|
||||
span_width(n) = n * column_width + (n - 1) * gutter // width of n columns
|
||||
```
|
||||
|
||||
Worked examples:
|
||||
|
||||
| Frame | margin | gutter | cols | content | column | 4-col span |
|
||||
|---|---|---|---|---|---|---|
|
||||
| 1920x1080 | 100 | 24 | 12 | 1720 | 121.3 | 557.3 |
|
||||
| 1080x1080 | 64 | 16 | 12 | 952 | 64.7 | 306.6 |
|
||||
| 1080x1920 | 48 | 16 | 6 | 984 | 150.7 | 650.6 |
|
||||
|
||||
Baseline / spacing: use an 8px base unit. Allowed spacing values: 4, 8, 16, 24, 32, 48, 64, 96. Type sizes also on the scale (e.g. 16/20/24/32/48/64/96). Everything snapping to multiples of 8 produces automatic visual cohesion.
|
||||
|
||||
Rule-of-thirds lines for any frame: verticals at `W/3` and `2W/3`, horizontals at `H/3` and `2H/3`. Power points = the four intersections. For 1920x1080: verticals 640 / 1280, horizontals 360 / 720.
|
||||
|
||||
## Safe-area percentages
|
||||
|
||||
Margins are fractions of the frame dimension on that side. Keep text, logos, faces, and CTAs inside.
|
||||
|
||||
| Aspect | Top | Bottom | Left | Right | Reason |
|
||||
|---|---|---|---|---|---|
|
||||
| 16:9 (1920x1080) | 5% (54px) | 5% (54px) | 5% (96px) | 5% (96px) | general web/video; 10% for broadcast |
|
||||
| 9:16 (1080x1920) | 13% (250px) | 19% (365px) | 6% (65px) | 6% (65px) | top status/caption, bottom CTA bar + nav |
|
||||
| 1:1 (1080x1080) | 7% (76px) | 7% (76px) | 7% (76px) | 7% (76px) | feed crop symmetric |
|
||||
| 4:5 (1080x1350) | 8% (108px) | 8% (108px) | 6% (65px) | 6% (65px) | taller feed crop |
|
||||
|
||||
9:16 platform-specific danger zones (approximate, design around these): TikTok right-rail icons occupy the right ~12% mid-to-lower; caption/handle sit in the bottom ~15-20%; Instagram Reels similar. Center the focal subject so it survives all crops, then reflow secondary content per aspect.
|
||||
|
||||
Multi-aspect strategy: design the master in 16:9 with the focal point near the vertical center band; for 9:16, restack horizontally-arranged elements into a vertical stack (don't merely crop the sides), enlarge type ~15-25%, and pull the focal point up toward the upper-middle to clear the bottom UI.
|
||||
|
||||
## Parallax layering
|
||||
|
||||
### CSS scroll-driven (pure CSS, modern browsers)
|
||||
|
||||
```css
|
||||
@keyframes parallax { to { translate: 0 calc(var(--speed) * 200px); } }
|
||||
.layer { animation: parallax linear; animation-timeline: scroll(root block); }
|
||||
.bg { --speed: 0.2; }
|
||||
.mid { --speed: 0.6; }
|
||||
.fg { --speed: 1.2; }
|
||||
```
|
||||
|
||||
### Pointer / mouse parallax (JS)
|
||||
|
||||
```js
|
||||
const layers = [
|
||||
{ el: document.querySelector('.bg'), depth: 0.2 },
|
||||
{ el: document.querySelector('.mid'), depth: 0.6 },
|
||||
{ el: document.querySelector('.fg'), depth: 1.2 },
|
||||
];
|
||||
addEventListener('pointermove', (e) => {
|
||||
const x = (e.clientX / innerWidth - 0.5) * 2; // -1..1
|
||||
const y = (e.clientY / innerHeight - 0.5) * 2;
|
||||
for (const { el, depth } of layers) {
|
||||
el.style.transform = `translate3d(${-x * depth * 30}px, ${-y * depth * 30}px, 0)`;
|
||||
}
|
||||
});
|
||||
```
|
||||
|
||||
Background depth 0.1-0.3, midground 0.5-0.7, foreground 1.0-1.5. Foreground may exceed 1.0 to read as very close; apply a slight blur to foreground layers as they cross the subject.
|
||||
|
||||
### Three.js depth parallax
|
||||
|
||||
```js
|
||||
// Place planes at different z; perspective camera makes nearer planes move more
|
||||
camera.position.z = 5;
|
||||
bg.position.z = -8; // far -> moves least
|
||||
mid.position.z = -2;
|
||||
fg.position.z = 1.5; // near -> moves most
|
||||
function onMove(nx, ny) { // nx, ny in -1..1
|
||||
camera.position.x = nx * 0.6;
|
||||
camera.position.y = ny * 0.4;
|
||||
camera.lookAt(0, 0, 0);
|
||||
}
|
||||
```
|
||||
|
||||
## Named camera-move recipes
|
||||
|
||||
### Push-in (dolly in) — build focus/intimacy
|
||||
|
||||
```
|
||||
scale 1.0 -> 1.12 over 1600ms, ease-in-out
|
||||
origin: the subject (transform-origin at focal point)
|
||||
optional: slight bg blur ramp 0 -> 3px to add depth cue
|
||||
```
|
||||
|
||||
### Pull-out (reveal context)
|
||||
|
||||
```
|
||||
scale 1.15 -> 1.0 over 1800ms, ease-in-out, origin centered
|
||||
```
|
||||
|
||||
### Whip-pan (energetic transition between scenes)
|
||||
|
||||
```
|
||||
translateX 0 -> -120% over 280ms, ease-in (accelerate out)
|
||||
add motion blur (CSS: filter blur on X, or directional blur in compositor)
|
||||
incoming scene: translateX 120% -> 0 over 280ms ease-out, overlapped
|
||||
```
|
||||
|
||||
### Pan / move (reveal space)
|
||||
|
||||
```
|
||||
translateX 0 -> -300px over 1500ms ease-in-out
|
||||
keep the subject leading: frame it ~1/3 from the trailing edge so it "leads" into open space
|
||||
```
|
||||
|
||||
### Orbit (3D)
|
||||
|
||||
```js
|
||||
// angle sweep around subject at fixed radius
|
||||
const r = 6, a0 = 0, a1 = Math.PI / 4, dur = 2000; // 45deg over 2s
|
||||
// ease t in 0..1, then:
|
||||
const a = a0 + (a1 - a0) * easeInOut(t);
|
||||
camera.position.set(Math.sin(a) * r, camera.position.y, Math.cos(a) * r);
|
||||
camera.lookAt(target);
|
||||
```
|
||||
|
||||
### Dolly-zoom (vertigo) — unsettling, dramatic
|
||||
|
||||
Move the camera toward the subject while zooming out (or vice versa) so the subject stays the same size but the background warps.
|
||||
|
||||
```js
|
||||
// keep subject screen-size constant: as camera moves closer (z down), widen FOV
|
||||
const baseDist = 8, baseFov = 35;
|
||||
function dollyZoom(dist) {
|
||||
camera.position.z = dist;
|
||||
// maintain framing: fov such that subjectHeight subtends same angle
|
||||
camera.fov = 2 * Math.atan((Math.tan((baseFov * Math.PI/180)/2) * baseDist) / dist) * 180/Math.PI;
|
||||
camera.updateProjectionMatrix();
|
||||
}
|
||||
// animate dist from 8 -> 4 over ~2000ms ease-in-out
|
||||
```
|
||||
|
||||
### General rules
|
||||
|
||||
- One move per beat. Combining push + pan + rotate reads as chaos; pick the single move that serves the moment.
|
||||
- Slower = more cinematic and expensive-looking; 800-2000ms for hero camera moves.
|
||||
- Lead moving subjects: frame them off-center toward the trailing edge so there's open space in the direction of travel.
|
||||
- Enter/exit through the nearest edge: ease-out (slight overshoot) on enter, ease-in (accelerate) on exit, following reading direction for natural feel.
|
||||
|
||||
---
|
||||
Respect the grid and safe areas and the camera move guides the eye. Built by **[iart.ai](https://iart.ai/?utm_source=github&utm_medium=readme&utm_campaign=motion-design-skills&utm_content=skill_footer&utm_term=shot-composition)** — the AI motion agent for editable, on-brand motion graphics.
|
||||
@@ -1,167 +0,0 @@
|
||||
---
|
||||
name: svg-animation
|
||||
description: This skill should be used when the user asks to "animate an SVG", "make a line draw itself on", "do a stroke draw-on / signature animation", "morph one shape into another", "move an element along a path", "animate an icon/logo", or "animate an SVG gradient or filter". Covers stroke-dashoffset draw-on, path morphing, motion-along-path, and animated icons/gradients/filters via CSS, SMIL, and GSAP.
|
||||
version: 0.1.0
|
||||
---
|
||||
|
||||
# SVG Animation
|
||||
|
||||
Crisp, lightweight, infinitely scalable vector motion — ideal for icons, illustrations, logos, and data marks. SVG can be animated three ways: CSS (declarative, simple), SMIL (`<animate>` inside the SVG), and JS (GSAP/Web Animations, for control and morphing). Choose per task; the techniques below say which.
|
||||
|
||||
## When to use
|
||||
|
||||
- Stroke "draw-on" of icons, illustrations, signatures, maps
|
||||
- Shape/path morphing and animated icon state changes (menu ↔ close, play ↔ pause)
|
||||
- Moving an element along a path (motion path)
|
||||
- Animated gradients, filters (glow, displacement), and animated logos
|
||||
|
||||
## Core techniques
|
||||
|
||||
### Stroke draw-on (the staple)
|
||||
|
||||
Draw the dash array as long as the path, offset it fully (invisible), then animate the offset to 0.
|
||||
|
||||
```css
|
||||
.path {
|
||||
stroke-dasharray: var(--len);
|
||||
stroke-dashoffset: var(--len);
|
||||
animation: draw 1.4s ease forwards;
|
||||
}
|
||||
@keyframes draw { to { stroke-dashoffset: 0; } }
|
||||
```
|
||||
|
||||
Getting the length:
|
||||
- JS (most reliable): `const len = path.getTotalLength(); path.style.setProperty("--len", len);`
|
||||
- No-JS trick: set `pathLength="1"` on the `<path>`, then `stroke-dasharray: 1; stroke-dashoffset: 1;` and animate to `0`. This normalizes any path to a 0–1 length so no measurement is needed.
|
||||
|
||||
Reverse (erase) by animating offset from 0 back to `len`. Stagger multiple paths with `animation-delay`. Direction of drawing follows the path's point order; reverse it in the editor or negate the offset sign if it draws "backwards".
|
||||
|
||||
### Morphing one path into another
|
||||
|
||||
Paths interpolate point-by-point, so a naive morph requires both `d` attributes to have the **same number and type of commands**. Two robust approaches:
|
||||
|
||||
- **GSAP MorphSVG** (free as of GSAP 3.12) — handles mismatched point counts automatically and finds a good mapping:
|
||||
|
||||
```js
|
||||
gsap.registerPlugin(MorphSVGPlugin);
|
||||
gsap.to("#start", { morphSVG: "#end", duration: 0.8, ease: "power2.inOut" });
|
||||
// Convert any shape to a morph-able path:
|
||||
MorphSVGPlugin.convertToPath("circle, rect, ellipse, line, polygon");
|
||||
```
|
||||
|
||||
- **Flubber** (small standalone lib) — generates interpolators without GSAP, good with React/Framer Motion:
|
||||
|
||||
```js
|
||||
import { interpolate } from "flubber";
|
||||
const interpolator = interpolate(pathA, pathB, { maxSegmentLength: 2 });
|
||||
// interpolator(0) === pathA, interpolator(1) === pathB; feed t into a tween.
|
||||
```
|
||||
|
||||
For hand-authored morphs (icon toggles), keep both paths with identical command structure and animate `d` directly via Web Animations or CSS (`d` is animatable in modern browsers via `path("...")`).
|
||||
|
||||
### Motion along a path
|
||||
|
||||
- **GSAP MotionPath** (preferred — control, alignment, scrub):
|
||||
|
||||
```js
|
||||
gsap.registerPlugin(MotionPathPlugin);
|
||||
gsap.to("#rocket", {
|
||||
duration: 4, repeat: -1, ease: "none",
|
||||
motionPath: { path: "#track", align: "#track", autoRotate: true, alignOrigin: [0.5, 0.5] },
|
||||
});
|
||||
```
|
||||
|
||||
`autoRotate: true` orients the object to the path tangent; `align` makes coordinates relative to the path element.
|
||||
|
||||
- **SMIL** (no JS):
|
||||
|
||||
```svg
|
||||
<path id="track" d="M10,80 C40,10 120,10 150,80" fill="none"/>
|
||||
<circle r="6" fill="#3b82f6">
|
||||
<animateMotion dur="3s" repeatCount="indefinite" rotate="auto">
|
||||
<mpath href="#track"/>
|
||||
</animateMotion>
|
||||
</circle>
|
||||
```
|
||||
|
||||
- **CSS** offset-path (modern, declarative): `offset-path: path("M10,80 C..."); animation: move 3s linear infinite;` with `@keyframes move { to { offset-distance: 100%; } }` and `offset-rotate: auto`.
|
||||
|
||||
### Animated gradients and filters
|
||||
|
||||
Gradients: animate `gradientTransform` or stop offsets. A sheen sweep:
|
||||
|
||||
```svg
|
||||
<linearGradient id="sheen">
|
||||
<stop offset="0%" stop-color="#fff" stop-opacity="0"/>
|
||||
<stop offset="50%" stop-color="#fff" stop-opacity=".8"/>
|
||||
<stop offset="100%" stop-color="#fff" stop-opacity="0"/>
|
||||
<animateTransform attributeName="gradientTransform" type="translate"
|
||||
from="-1 0" to="1 0" dur="2s" repeatCount="indefinite"/>
|
||||
</linearGradient>
|
||||
```
|
||||
|
||||
Filters: animate `feDisplacementMap` `scale` for gooey/wobble, `feGaussianBlur` `stdDeviation` for focus pulls, or `feColorMatrix`/`feFlood` for glow. Filters are paint-heavy — animate sparingly and prefer `transform`/`opacity` where possible.
|
||||
|
||||
## Implementation choice (pick fast)
|
||||
|
||||
| Need | Use |
|
||||
|------|-----|
|
||||
| Single declarative draw/fade | CSS |
|
||||
| Self-contained, no JS bundle | SMIL (`<animate*>` in the SVG) |
|
||||
| Coordinated, scrubbable, scroll-tied | GSAP |
|
||||
| Mismatched-point morph | GSAP MorphSVG or Flubber |
|
||||
| Path following with rotation | GSAP MotionPath / CSS offset-path |
|
||||
|
||||
SMIL caveat: not supported in IE/old Edge and historically deprecation-flagged; for max reach or scroll-syncing, prefer CSS or JS. SMIL is still fine for self-contained icon assets in evergreen browsers.
|
||||
|
||||
## Authoring and optimization
|
||||
|
||||
- Build/clean with **SVGO**: keep `viewBox`, drop editor metadata, but disable `cleanupIds`/`removeViewBox` and any plugin that renames IDs you reference from CSS/JS/SMIL. Disable `mergePaths` and `convertShapeToPath` if you animate individual sub-paths or shapes.
|
||||
- Inline the SVG in the DOM (not `<img src>`) so CSS/JS can reach its internals; `<img>`-embedded SVG can only self-animate via internal SMIL/CSS.
|
||||
- Set explicit `viewBox` and avoid fixed `width`/`height` so the asset scales fluidly.
|
||||
- For draw-on, ensure paths are actual strokes (`fill:none; stroke:...`), not filled outlines — dashoffset only affects strokes.
|
||||
- Respect `prefers-reduced-motion`: gate looping/large motion; keep a static final state.
|
||||
|
||||
## Deliver & verify (standalone HTML)
|
||||
|
||||
> **Packaged helper** (`scripts/`): `scripts/seek-shot.sh anim.html 0 1.5 3` freezes the `?t=N` harness and screenshots each moment; `scripts/contact-sheet.sh sheet.png frame-*.png` tiles them for one-glance review. See `scripts/README.md`.
|
||||
|
||||
For a self-contained icon/logo/draw-on the deliverable is **one HTML file that opens directly in a browser** — inline the SVG in the markup, drive the animation with one mechanism, no build step. One file is the right tier for a vector asset; don't reach for a bundler.
|
||||
|
||||
**Output contract:**
|
||||
- One `.html` file: inline `<svg>`, plus CSS `@keyframes` / a `<script>` with GSAP from CDN / SMIL `<animate*>` — pick one driver.
|
||||
- Include the seek harness matching that driver so any moment can be frozen for a screenshot.
|
||||
|
||||
**Seek harness — freeze an exact moment.** `?t=N` seeks and pauses so a screenshot lands on a still frame. Use the mechanism that matches how the SVG animates:
|
||||
|
||||
```html
|
||||
<script>
|
||||
const t = new URLSearchParams(location.search).get("t");
|
||||
if (t !== null) {
|
||||
const N = parseFloat(t);
|
||||
// SMIL: pause the SVG's own clock and scrub it
|
||||
const svg = document.querySelector("svg");
|
||||
svg.pauseAnimations(); svg.setCurrentTime(N);
|
||||
// CSS @keyframes draw-on: el.style.animationDelay=(-N)+"s"; el.style.animationPlayState="paused";
|
||||
// GSAP timeline: tl.pause(); tl.seek(N);
|
||||
}
|
||||
window.__ready = true;
|
||||
</script>
|
||||
```
|
||||
|
||||
**Verify loop — render → freeze → screenshot → check:** open the file at start / mid / end (`?t=0`, `?t=<dur/2>`, `?t=<dur>`), screenshot each, and check **fidelity** (stroke draws in the right direction, morph endpoints clean) plus **artifacts** (path clipped by `viewBox`, stroke vanishing from a stale dashoffset, FOUC, jank at the morph seam). Any headless tool works:
|
||||
|
||||
```bash
|
||||
npx playwright screenshot --wait-for-timeout=500 "file://$PWD/icon.html?t=0.7" frame-mid.png
|
||||
```
|
||||
|
||||
**Before you finish:**
|
||||
1. Opens standalone — no console errors, inline SVG reachable, CDN (if any) loads.
|
||||
2. The seek mechanism for your driver freezes a deterministic frame.
|
||||
3. Screenshotted at start / mid / end — matches the brief, no clipping or off-`viewBox` strokes.
|
||||
4. `prefers-reduced-motion` honored — looping/large motion gated, static final state kept.
|
||||
5. Easing is intentional — `ease`/GSAP ease chosen on purpose, no accidental `linear` draw-on.
|
||||
|
||||
## Reference files
|
||||
|
||||
- `references/svg-techniques.md` — full dashoffset math and `getTotalLength` gotchas, the `pathLength="1"` normalization, GSAP MorphSVG vs Flubber decision guide with code, an icon-toggle morph (hamburger↔close), MotionPath/offset-path details, SMIL-vs-CSS-vs-JS tradeoffs, and an SVGO config tuned for animation.
|
||||
@@ -1,214 +0,0 @@
|
||||
# SVG Animation Techniques (detailed)
|
||||
|
||||
## 1. Stroke draw-on: the math
|
||||
|
||||
`stroke-dasharray` defines a dash pattern; `stroke-dashoffset` shifts where the pattern starts. Set the dash equal to the whole path length and offset it by that same length → the visible dash is pushed entirely off the path (invisible). Animating offset to 0 slides the dash into view, revealing the stroke progressively.
|
||||
|
||||
```
|
||||
visible fraction = 1 - (dashoffset / pathLength)
|
||||
```
|
||||
|
||||
So offset = length → 0% drawn; offset = 0 → 100% drawn; offset = length/2 → 50% drawn (useful for scroll mapping: `offset = length * (1 - progress)`).
|
||||
|
||||
### getTotalLength gotchas
|
||||
|
||||
```js
|
||||
const path = document.querySelector("#sig");
|
||||
const len = path.getTotalLength(); // returns user units of the path geometry
|
||||
path.style.strokeDasharray = len;
|
||||
path.style.strokeDashoffset = len;
|
||||
requestAnimationFrame(() => { // next frame so the transition has a start value
|
||||
path.style.transition = "stroke-dashoffset 1.6s ease";
|
||||
path.style.strokeDashoffset = "0";
|
||||
});
|
||||
```
|
||||
|
||||
- `getTotalLength()` measures the path's own coordinate system, ignoring CSS transforms/scaling — which is what you want for dasharray.
|
||||
- It only works on geometry elements (`path, line, polyline, polygon, circle, ellipse, rect`). For `<text>` draw-on you must convert text to paths first.
|
||||
- Rounding: browsers can clip the last sub-pixel; pad slightly (`len + 1`) if the end never fully closes.
|
||||
- Compound paths (multiple `M` subpaths in one `d`) draw all subpaths simultaneously. Split into separate `<path>`s with staggered `animation-delay` for sequential drawing.
|
||||
|
||||
### No-JS normalization with pathLength
|
||||
|
||||
`pathLength="1"` tells the browser to treat the path's length as exactly 1, regardless of real geometry. Then dash math is unit-free:
|
||||
|
||||
```svg
|
||||
<path d="..." pathLength="1" fill="none" stroke="#111"
|
||||
style="stroke-dasharray:1; stroke-dashoffset:1; animation:draw 1.4s ease forwards"/>
|
||||
```
|
||||
```css
|
||||
@keyframes draw { to { stroke-dashoffset: 0; } }
|
||||
```
|
||||
|
||||
This is the cleanest pure-CSS draw-on and avoids hardcoding measured lengths that break when the path is edited. Use `pathLength="100"` if you prefer to think in percentages.
|
||||
|
||||
### Scroll-driven draw-on (no library, via offset)
|
||||
|
||||
```js
|
||||
const len = path.getTotalLength();
|
||||
path.style.strokeDasharray = len;
|
||||
function onScroll() {
|
||||
const p = Math.min(1, Math.max(0, scrollProgress())); // 0..1
|
||||
path.style.strokeDashoffset = len * (1 - p);
|
||||
}
|
||||
document.addEventListener("scroll", onScroll, { passive: true });
|
||||
```
|
||||
|
||||
## 2. Morphing
|
||||
|
||||
### Why naive morphs break
|
||||
|
||||
Path interpolation walks the `d` command list of A and B in lockstep. If A has 4 cubic curves and B has 7, or A uses `L` where B uses `C`, the browser/animator either refuses or produces garbage. Fixes: match commands by hand, or use a library that resamples.
|
||||
|
||||
### GSAP MorphSVG (best for arbitrary shapes)
|
||||
|
||||
```js
|
||||
import gsap from "gsap";
|
||||
import { MorphSVGPlugin } from "gsap/MorphSVGPlugin";
|
||||
gsap.registerPlugin(MorphSVGPlugin);
|
||||
|
||||
// any shape -> path so it can morph
|
||||
MorphSVGPlugin.convertToPath("#circ, #star");
|
||||
|
||||
gsap.to("#circ", {
|
||||
duration: 0.9, ease: "power2.inOut",
|
||||
morphSVG: { shape: "#star", shapeIndex: "auto", type: "rotational" },
|
||||
});
|
||||
```
|
||||
|
||||
- `shapeIndex` rotates the starting point mapping to minimize twisting; `"auto"` lets GSAP pick, or pass a number to tune.
|
||||
- `type: "rotational"` interpolates angles/lengths instead of raw coordinates — usually smoother for organic morphs.
|
||||
- `map: "size" | "position" | "complexity"` changes how sub-paths in compound shapes are matched.
|
||||
|
||||
### Flubber (standalone, framework-friendly)
|
||||
|
||||
```js
|
||||
import { interpolate, separate, combine } from "flubber";
|
||||
|
||||
// 1 -> 1 shape
|
||||
const lerp = interpolate(pathA, pathB, { maxSegmentLength: 2 });
|
||||
|
||||
// splitting one shape into many (or vice versa)
|
||||
const split = separate(oneShape, [shape1, shape2, shape3], { single: true });
|
||||
```
|
||||
|
||||
Drive `lerp(t)` with any tween/`requestAnimationFrame`, or inside Framer Motion:
|
||||
|
||||
```jsx
|
||||
import { motion, useMotionValue, useTransform, animate } from "motion/react";
|
||||
const progress = useMotionValue(0);
|
||||
const d = useTransform(progress, [0, 1], [0, 1], { clamp: false });
|
||||
const path = useTransform(d, (v) => interpolate(A, B)(v));
|
||||
// animate(progress, 1, { duration: 0.6 }) then <motion.path d={path} />
|
||||
```
|
||||
|
||||
Use Flubber when you can't add GSAP or need React-native value plumbing; use MorphSVG for the highest-quality mapping and convenience.
|
||||
|
||||
### Hand-authored icon toggle (hamburger ↔ close) — no morph library
|
||||
|
||||
When you control both shapes, give them identical structure and animate transforms instead of `d`:
|
||||
|
||||
```svg
|
||||
<svg viewBox="0 0 24 24" class="menu" aria-label="Menu">
|
||||
<line class="top" x1="3" y1="6" x2="21" y2="6"/>
|
||||
<line class="mid" x1="3" y1="12" x2="21" y2="12"/>
|
||||
<line class="bot" x1="3" y1="18" x2="21" y2="18"/>
|
||||
</svg>
|
||||
```
|
||||
```css
|
||||
.menu line { stroke:#111; stroke-width:2; transition: transform .25s ease, opacity .2s ease;
|
||||
transform-origin: center; transform-box: fill-box; }
|
||||
.menu.open .top { transform: translateY(6px) rotate(45deg); }
|
||||
.menu.open .mid { opacity: 0; }
|
||||
.menu.open .bot { transform: translateY(-6px) rotate(-45deg); }
|
||||
```
|
||||
|
||||
`transform-box: fill-box` makes `transform-origin: center` resolve to the element's own bounding box — essential for SVG rotation; without it the origin is the SVG viewport origin.
|
||||
|
||||
## 3. Motion along a path — details
|
||||
|
||||
### GSAP MotionPath
|
||||
|
||||
```js
|
||||
gsap.to("#dot", {
|
||||
duration: 5, repeat: -1, ease: "none",
|
||||
motionPath: {
|
||||
path: "#route",
|
||||
align: "#route", // coordinates relative to the path element
|
||||
alignOrigin: [0.5, 0.5], // pin the object's center to the path
|
||||
autoRotate: true, // or a number to add a constant offset angle
|
||||
start: 0, end: 1, // animate a sub-segment, e.g. 0.2..0.8
|
||||
},
|
||||
});
|
||||
```
|
||||
|
||||
Convert a series of points into a smooth path: `MotionPathPlugin.convertToPath(...)`, or pass `motionPath: [{x:0,y:0},{x:100,y:50},...]` and GSAP draws a curve through them.
|
||||
|
||||
### CSS offset-path (declarative, modern)
|
||||
|
||||
```css
|
||||
.dot {
|
||||
offset-path: path("M10,80 C40,10 120,10 150,80");
|
||||
offset-rotate: auto; /* face direction of travel */
|
||||
animation: travel 3s linear infinite;
|
||||
}
|
||||
@keyframes travel { to { offset-distance: 100%; } }
|
||||
```
|
||||
|
||||
Newer syntax also accepts `offset-path: url(#route)` referencing a `<path>` id and shapes like `ray()`. Good support in evergreen browsers; no JS needed.
|
||||
|
||||
### SMIL animateMotion
|
||||
|
||||
Self-contained inside the SVG; use `rotate="auto"` and `<mpath href="#id"/>`. Best for portable icon assets where you don't want external CSS/JS. Avoid when you need scroll-sync or broad legacy support.
|
||||
|
||||
## 4. SMIL vs CSS vs JS — tradeoffs
|
||||
|
||||
| Axis | SMIL | CSS | JS (GSAP/WAAPI) |
|
||||
|------|------|-----|-----------------|
|
||||
| Bundle cost | none (inline) | none | library (GSAP ~JS) |
|
||||
| Works in `<img>` SVG | yes | yes (internal) | no |
|
||||
| Reach (legacy IE/Edge) | no | partial | yes |
|
||||
| Scroll/scrub sync | hard | hard | easy |
|
||||
| Morph mismatched paths | no | no | yes (MorphSVG/Flubber) |
|
||||
| Timeline orchestration | limited | limited | full |
|
||||
| Animate `d`/gradients/filters | yes | partial | yes |
|
||||
|
||||
Default: CSS for simple declarative effects, GSAP for anything coordinated/scrubbable/morphing, SMIL only for portable self-animating assets in evergreen targets.
|
||||
|
||||
## 5. SVGO config tuned for animation
|
||||
|
||||
Aggressive SVGO defaults will strip the very things you animate. Use a config like:
|
||||
|
||||
```js
|
||||
// svgo.config.js
|
||||
module.exports = {
|
||||
multipass: true,
|
||||
plugins: [
|
||||
{ name: "preset-default", params: { overrides: {
|
||||
removeViewBox: false, // keep responsive scaling
|
||||
cleanupIds: false, // DO NOT rename ids referenced by CSS/JS/SMIL/gradients
|
||||
mergePaths: false, // keep sub-paths separate for staggered draw-on
|
||||
convertShapeToPath: false, // keep <circle>/<rect> if SMIL/CSS targets them
|
||||
removeHiddenElems: false, // keep elements you toggle visible via animation
|
||||
inlineStyles: false, // preserve class hooks
|
||||
} } },
|
||||
{ name: "removeDimensions" }, // drop width/height, keep viewBox -> fluid scaling
|
||||
{ name: "prefixIds" }, // namespace ids if inlining many SVGs to avoid id collisions
|
||||
],
|
||||
};
|
||||
```
|
||||
|
||||
If multiple inlined SVGs share gradient/filter ids, id collisions make the LAST definition win for everyone — `prefixIds` (or unique authoring) prevents this classic bug.
|
||||
|
||||
## 6. Reduced motion
|
||||
|
||||
```css
|
||||
@media (prefers-reduced-motion: reduce) {
|
||||
.path { animation: none; stroke-dashoffset: 0; } /* show final drawn state instantly */
|
||||
}
|
||||
```
|
||||
|
||||
For looping decorative SVG (spinners, ambient gradients), pause or hide them under reduced-motion; for functional icon toggles, keep the state change but drop the easing duration.
|
||||
|
||||
---
|
||||
Pick the right method per shape and SVG draws, morphs, and travels smoothly. Built by **[iart.ai](https://iart.ai/?utm_source=github&utm_medium=readme&utm_campaign=web-animation-skills&utm_content=skill_footer&utm_term=svg-animation)** — the AI motion agent for editable, on-brand motion graphics.
|
||||
@@ -1 +0,0 @@
|
||||
../../.agents/skills/60fps-animation
|
||||
@@ -1 +0,0 @@
|
||||
../../.agents/skills/accessible-animation
|
||||
Symlink
+1
@@ -0,0 +1 @@
|
||||
../../.agents/skills/after-effects
|
||||
+1
@@ -0,0 +1 @@
|
||||
../../.agents/skills/animation-principles
|
||||
@@ -1 +0,0 @@
|
||||
../../.agents/skills/ascii-animation
|
||||
Symlink
+1
@@ -0,0 +1 @@
|
||||
../../.agents/skills/beat-sync-editing
|
||||
Symlink
+1
@@ -0,0 +1 @@
|
||||
../../.agents/skills/color-motion
|
||||
@@ -1 +0,0 @@
|
||||
../../.agents/skills/glassmorphism
|
||||
@@ -1 +0,0 @@
|
||||
../../.agents/skills/gsap-web
|
||||
Symlink
+1
@@ -0,0 +1 @@
|
||||
../../.agents/skills/logo-animation
|
||||
@@ -1 +0,0 @@
|
||||
../../.agents/skills/lottie-animation
|
||||
@@ -1 +0,0 @@
|
||||
../../.agents/skills/micro-interaction
|
||||
+1
@@ -0,0 +1 @@
|
||||
../../.agents/skills/motion-art-direction
|
||||
Symlink
+1
@@ -0,0 +1 @@
|
||||
../../.agents/skills/motion-background
|
||||
@@ -1 +0,0 @@
|
||||
../../.agents/skills/page-transition-animation
|
||||
Symlink
+1
@@ -0,0 +1 @@
|
||||
../../.agents/skills/shot-composition
|
||||
@@ -1 +0,0 @@
|
||||
../../.agents/skills/svg-animation
|
||||
+36
-36
@@ -1,59 +1,59 @@
|
||||
{
|
||||
"version": 1,
|
||||
"skills": {
|
||||
"60fps-animation": {
|
||||
"source": "iart-ai/web-animation-skills",
|
||||
"after-effects": {
|
||||
"source": "iart-ai/motion-design-skills",
|
||||
"sourceType": "github",
|
||||
"skillPath": "skills/60fps-animation/SKILL.md",
|
||||
"computedHash": "d832ea4a0dc07c18483d4fd39352c65e4daa2f298998290730cf159df30f400e"
|
||||
"skillPath": "skills/after-effects/SKILL.md",
|
||||
"computedHash": "9db077d9664f5c45157c53b754d3c72bb346999a260c63d3d4892745a3eefd02"
|
||||
},
|
||||
"accessible-animation": {
|
||||
"source": "iart-ai/web-animation-skills",
|
||||
"animation-principles": {
|
||||
"source": "iart-ai/motion-design-skills",
|
||||
"sourceType": "github",
|
||||
"skillPath": "skills/accessible-animation/SKILL.md",
|
||||
"computedHash": "46695e422851b64f2b680924584ba9f7690309c109b6d98925ef3021b139167c"
|
||||
"skillPath": "skills/animation-principles/SKILL.md",
|
||||
"computedHash": "140b00a44e08aa7649fb1cce1c48670ff2e76f3889fbac0b5311cc5bb818d7b7"
|
||||
},
|
||||
"ascii-animation": {
|
||||
"source": "iart-ai/web-animation-skills",
|
||||
"beat-sync-editing": {
|
||||
"source": "iart-ai/motion-design-skills",
|
||||
"sourceType": "github",
|
||||
"skillPath": "skills/ascii-animation/SKILL.md",
|
||||
"computedHash": "cc219b1851f713f76934a2738ccdcec37d4a266f1d20ecc346487290cc40d2fb"
|
||||
"skillPath": "skills/beat-sync-editing/SKILL.md",
|
||||
"computedHash": "4089a0b65782c529ebd4fe9a576588fb51cf716573b4d683b0494e6554e61e03"
|
||||
},
|
||||
"glassmorphism": {
|
||||
"source": "iart-ai/web-animation-skills",
|
||||
"color-motion": {
|
||||
"source": "iart-ai/motion-design-skills",
|
||||
"sourceType": "github",
|
||||
"skillPath": "skills/glassmorphism/SKILL.md",
|
||||
"computedHash": "c98e77044561fea5e51116156d0ba600a56f9961ed18b498d72504d49aff7882"
|
||||
"skillPath": "skills/color-motion/SKILL.md",
|
||||
"computedHash": "7c05f7d35427d5fbe2fd1b5b6c0622252314a049797085fce085085cbf4c3e6e"
|
||||
},
|
||||
"gsap-web": {
|
||||
"source": "iart-ai/web-animation-skills",
|
||||
"logo-animation": {
|
||||
"source": "iart-ai/motion-design-skills",
|
||||
"sourceType": "github",
|
||||
"skillPath": "skills/gsap-web/SKILL.md",
|
||||
"computedHash": "11585ce3142acae8db34c9d0eb57e03834972f1095643266eb2c41b432564b1d"
|
||||
"skillPath": "skills/logo-animation/SKILL.md",
|
||||
"computedHash": "3bba34771ff84fa7e68dc8026e195aab411a82b01091c9427fc8f3c8e48e7d99"
|
||||
},
|
||||
"lottie-animation": {
|
||||
"source": "iart-ai/web-animation-skills",
|
||||
"motion-art-direction": {
|
||||
"source": "iart-ai/motion-design-skills",
|
||||
"sourceType": "github",
|
||||
"skillPath": "skills/lottie-animation/SKILL.md",
|
||||
"computedHash": "3b9838145f5af19d03014a5eca9041ae0ba267b77e312332a129f3fe40078f68"
|
||||
"skillPath": "skills/motion-art-direction/SKILL.md",
|
||||
"computedHash": "bcba09b729fd3d99b3b1a388c3aaac655a3771b26dc3e8d077a110dfdd9e1631"
|
||||
},
|
||||
"micro-interaction": {
|
||||
"source": "iart-ai/web-animation-skills",
|
||||
"motion-background": {
|
||||
"source": "iart-ai/motion-design-skills",
|
||||
"sourceType": "github",
|
||||
"skillPath": "skills/micro-interaction/SKILL.md",
|
||||
"computedHash": "f236bc97a9f4c0e9c9a045d0b591e3ca6b6b2aeb26e42b661c15211f652ac131"
|
||||
"skillPath": "skills/motion-background/SKILL.md",
|
||||
"computedHash": "99a576ac6549791b410abbc48a18074fed9e7925cf3ee5392108c59ad9e25fa4"
|
||||
},
|
||||
"page-transition-animation": {
|
||||
"source": "iart-ai/web-animation-skills",
|
||||
"remotion-video": {
|
||||
"source": "iart-ai/motion-design-skills",
|
||||
"sourceType": "github",
|
||||
"skillPath": "skills/page-transition-animation/SKILL.md",
|
||||
"computedHash": "62e103e2313433e77db26c67fdcae1c425030e1a51d0f5ffc0fb6fdac6d36132"
|
||||
"skillPath": "skills/remotion-video/SKILL.md",
|
||||
"computedHash": "940885087443f4aa5d3baf6edb4ed25edafea2435b52922e120200b4c1af99ba"
|
||||
},
|
||||
"svg-animation": {
|
||||
"source": "iart-ai/web-animation-skills",
|
||||
"shot-composition": {
|
||||
"source": "iart-ai/motion-design-skills",
|
||||
"sourceType": "github",
|
||||
"skillPath": "skills/svg-animation/SKILL.md",
|
||||
"computedHash": "b6902577f093a1cd724052b94e633154cb42020b5001138185982fb4ce230404"
|
||||
"skillPath": "skills/shot-composition/SKILL.md",
|
||||
"computedHash": "9ff4551d175f951fb443a0680020871eb93c5ae07a0f36a2008ca98e5d0fa324"
|
||||
}
|
||||
}
|
||||
}
|
||||
Reference in new issue
Block a user