Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01GYeokZtSmqg42ZGWsLXX2C
234 lines
9.3 KiB
Markdown
234 lines
9.3 KiB
Markdown
# Lottie Integration & Export (detailed)
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## 1. dotLottie-web full setup
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```bash
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npm i @lottiefiles/dotlottie-web
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```
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```js
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import { DotLottie } from "@lottiefiles/dotlottie-web";
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const dotLottie = new DotLottie({
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canvas: document.querySelector("#lottie"),
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src: "/assets/onboarding.lottie", // .lottie or .json (URL or same-origin path)
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autoplay: true,
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loop: true,
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speed: 1,
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mode: "forward", // forward | reverse | bounce | reverse-bounce
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useFrameInterpolation: true, // smoother than the source frame rate
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renderConfig: {
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autoResize: true, // keep the canvas crisp on resize/DPR changes
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devicePixelRatio: window.devicePixelRatio,
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},
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});
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```
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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.
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### Lifecycle and events
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```js
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dotLottie.addEventListener("load", () => console.log(dotLottie.totalFrames, dotLottie.duration));
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dotLottie.addEventListener("loadError", (e) => console.error("bad src", e));
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dotLottie.addEventListener("play", () => {});
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dotLottie.addEventListener("pause", () => {});
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dotLottie.addEventListener("complete", () => {}); // fires when a non-looping play finishes
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dotLottie.addEventListener("loop", ({ loopCount }) => {});
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dotLottie.addEventListener("frame", ({ currentFrame }) => {});
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// always clean up (SPA/unmount)
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dotLottie.destroy();
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```
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`totalFrames`, `duration`, and segment data are only valid AFTER the `load` event — read them there, not synchronously after construction.
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### Multi-animation .lottie files
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A single `.lottie` can hold several animations:
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```js
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dotLottie.addEventListener("load", () => {
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console.log(dotLottie.manifest.animations); // list of animation ids
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});
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dotLottie.loadAnimation("success"); // switch by id without re-fetching
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```
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## 2. React wrapper
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```bash
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npm i @lottiefiles/dotlottie-react
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```
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```jsx
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import { DotLottieReact } from "@lottiefiles/dotlottie-react";
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import { useState, useEffect } from "react";
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function PlayButton() {
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const [dl, setDl] = useState(null);
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const [playing, setPlaying] = useState(true);
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useEffect(() => {
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if (!dl) return;
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const onComplete = () => setPlaying(false);
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dl.addEventListener("complete", onComplete);
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return () => dl.removeEventListener("complete", onComplete);
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}, [dl]);
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return (
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<DotLottieReact
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src="/play.lottie"
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autoplay
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loop={false}
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dotLottieRefCallback={setDl} // capture instance for imperative control
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onClick={() => (playing ? dl.pause() : dl.play(), setPlaying((p) => !p))}
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style={{ width: 200, height: 200 }}
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/>
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);
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}
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```
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Props mirror the constructor: `src, autoplay, loop, speed, mode, useFrameInterpolation, renderConfig, themeId, segment`.
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## 3. Segments and state machines
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```js
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// Loop only the "loading" portion (frames 30–90), then jump to a success segment.
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dotLottie.setSegment(30, 90);
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dotLottie.setLoop(true);
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dotLottie.play();
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function resolveSuccess() {
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dotLottie.setLoop(false);
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dotLottie.setSegment(91, 140); // success burst
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dotLottie.play();
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}
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```
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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.
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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.
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## 4. lottie-interactivity (declarative)
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```bash
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npm i @lottiefiles/lottie-interactivity
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```
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Works with a `lottie-web`/dotLottie player instance (commonly the `<dotlottie-player>` / `<lottie-player>` web component):
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```html
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<dotlottie-player id="firstLottie" src="/scroll.lottie" style="width:300px"></dotlottie-player>
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<script>
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LottieInteractivity.create({
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player: "#firstLottie",
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mode: "scroll",
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actions: [
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{ visibility: [0, 0.3], type: "stop", frames: [0] },
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{ visibility: [0.3, 1.0], type: "seek", frames: [0, 120] }, // map scroll → frames 0..120
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],
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});
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</script>
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```
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Modes:
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- `scroll` — tie frames to scroll position / element visibility (the canonical scrolly use).
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- `cursor` — drive frames from cursor position over the element (hover scrub).
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- `hover` — play on hover, control `loop`/`reset` on leave.
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- `click` — advance to the next sync state on each click.
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- `chain` — sequence multiple animations.
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Use `type: "seek"` to scrub frames, `type: "loop"` / `"play"` / `"stop"` for segment behaviors.
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## 5. Manual scroll mapping (full control, no extra lib)
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```js
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const clamp = (v, lo, hi) => Math.min(hi, Math.max(lo, v));
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let total = 0;
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dotLottie.addEventListener("load", () => { total = dotLottie.totalFrames - 1; });
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const section = document.querySelector(".scrolly");
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function update() {
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const r = section.getBoundingClientRect();
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const scrollable = r.height - window.innerHeight;
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const p = clamp(-r.top / scrollable, 0, 1);
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dotLottie.setFrame(p * total);
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}
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window.addEventListener("scroll", update, { passive: true });
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window.addEventListener("resize", update);
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```
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Pause when offscreen to save CPU:
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```js
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new IntersectionObserver(([e]) => e.isIntersecting ? dotLottie.unfreeze() : dotLottie.freeze())
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.observe(canvas);
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```
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## 6. Runtime theming
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### Embedded themes (recommended)
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A `.lottie` authored with named color themes:
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```js
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dotLottie.addEventListener("load", () => {
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console.log(dotLottie.manifest.themes); // available theme ids
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dotLottie.setTheme("dark"); // swap colors with no re-fetch / re-export
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});
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// or per slot:
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dotLottie.setThemeData({ /* theme JSON */ });
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```
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### Manual color patching (last resort)
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```js
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const json = await fetch("/icon.json").then((r) => r.json());
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// Lottie colors are normalized 0..1 [r,g,b,a] arrays at shapes[].it[].c.k
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function recolor(layers, hex) {
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const [r, g, b] = hexToRgb01(hex);
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for (const layer of layers) {
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for (const sh of layer.shapes ?? []) {
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for (const it of sh.it ?? []) {
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if (it.ty === "fl" || it.ty === "st") { it.c.k = [r, g, b, 1]; } // fill / stroke
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}
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}
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if (layer.layers) recolor(layer.layers, hex); // precomps
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}
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}
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recolor(json.layers, "#ff5500");
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new DotLottie({ canvas, data: JSON.stringify(json), autoplay: true });
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```
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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.
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## 7. After Effects → Bodymovin export checklist
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Plugin: **Bodymovin** (or LottieFiles plugin). `Window → Extensions → Bodymovin`. Select the comp, set destination, configure, Render.
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Pre-export checklist:
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1. Comp set to a sensible size and frame rate (24/30/60); avoid huge resolutions — Lottie is vector, the canvas scales.
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2. Name layers/comps clearly — names survive into JSON and aid runtime theming/targeting.
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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.
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4. Trim the work area to exactly the frames you ship; trailing frames bloat the file.
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5. In Bodymovin settings: enable **Compress assets / .lottie** output for the zipped format; enable "Glyphs" if using text; toggle "Standalone"/"Demo" only as needed.
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6. Replace embedded raster images with vectors where possible; if rasters are required, they inflate `.json` (consider `.lottie` which bundles them).
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7. Test the exported file in the LottieFiles preview AND your target runtime before handoff — renderers differ.
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### Unsupported / partially-supported AE features (avoid or rework)
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- **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".
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- **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.
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- **3D layers / camera** — not supported; fake depth with 2D scaling/position.
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- **Time remapping / nested time stretch** — flaky; pre-compose and bake.
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- **Auto-Orient, certain merge-paths modes, some matte combinations** — test explicitly.
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- **Audio** — not part of Lottie.
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- **Adjustment layers, layer styles (bevel/emboss/inner shadow)** — largely unsupported; convert to shapes/gradients.
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- **Track mattes** — alpha/luma mattes generally work but increase cost; flatten when possible.
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- **Gradients on strokes / complex gradient feathering** — limited; verify.
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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.
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---
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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.
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