ever-just/agentskills

Motion Canvas — TypeScript Animation Engine for Explanatory Videos

A TypeScript library using generators to program animations with a real-time editor. Ideal for explainer videos, code walkthroughs, and educational content.

Overview

• Repo: github.com/motion-canvas/motion-canvas (18K+ stars)
• Language: TypeScript
• License: MIT
• Install: npm create @motion-canvas@latest
• Docs: motioncanvas.io/docs

Core Concepts

Project Setup

npm create @motion-canvas@latest my-animation
cd my-animation
npm install
npm start  # Opens editor at localhost:9000

Scenes

Every animation is composed of scenes. A scene is a generator function:

import { makeScene2D } from "@motion-canvas/2d";
import { createRef } from "@motion-canvas/core";
import { Circle } from "@motion-canvas/2d/lib/components";

export default makeScene2D(function* (view) {
  const circle = createRef<Circle>();

  view.add(<Circle ref={circle} size={100} fill="#e13238" />);

  // Animate the circle
  yield* circle().scale(2, 0.6);
  yield* circle().opacity(0, 0.3);
});

Animation with Generators

The yield* keyword drives animations frame by frame:

// Sequential animations (one after another)
yield* rect().position.x(300, 1);   // Move right over 1 second
yield* rect().fill("#00ff00", 0.5); // Change color over 0.5 seconds

// Parallel animations (simultaneous)
yield* all(
  rect().position.x(300, 1),
  rect().rotation(360, 1),
);

// Chained with delay
yield* chain(
  rect().opacity(1, 0.3),
  waitFor(0.5),
  rect().scale(2, 0.6),
);

// Wait for duration
yield* waitFor(2); // Wait 2 seconds

Nodes (Visual Elements)

import { Rect, Circle, Line, Txt, Img, Video, Layout } from "@motion-canvas/2d/lib/components";

// Rectangle
<Rect width={200} height={100} fill="#333" radius={10} />

// Text
<Txt text="Hello" fontSize={48} fill="white" fontFamily="monospace" />

// Circle
<Circle size={80} fill="#e13238" />

// Image
<Img src={myImage} width={400} />

// Layout (flexbox)
<Layout direction="column" gap={20} alignItems="center">
  <Txt text="Title" />
  <Rect width={200} height={50} />
</Layout>

Signals (Reactive Values)

import { createSignal } from "@motion-canvas/core";

const progress = createSignal(0);

// Use in components
<Rect width={() => progress() * 400} height={20} fill="blue" />

// Animate signal
yield* progress(1, 2); // Animate from 0 to 1 over 2 seconds

Easing

import { easeInOutCubic, easeOutBounce, linear } from "@motion-canvas/core";

yield* rect().position.x(300, 1, easeInOutCubic);
yield* circle().scale(2, 0.8, easeOutBounce);

Code Highlighting

import { Code, lines, word } from "@motion-canvas/2d/lib/components";

const code = createRef<Code>();

view.add(
  <Code
    ref={code}
    fontSize={24}
    code={`function hello() {\n  console.log("world");\n}`}
  />
);

// Highlight specific lines
yield* code().selection(lines(1, 2), 0.3);

// Animate code changes
yield* code().code(
  `function hello() {\n  return "world";\n}`,
  0.6,
);

Commands

# Start editor (live preview)
npm start

# Render to video
npx motion-canvas render

# Render specific scene
npx motion-canvas render --scene=myScene

Best Practices

1. Use refs for animation targets: createRef<Circle>() for any node you animate
2. Generator-based flow: Think sequentially — yield* is your timeline
3. Use all() for parallel: Group simultaneous animations
4. Signals for reactive data: Values that multiple nodes depend on
5. Layout component for flexbox: Auto-positions children
6. Keep scenes short: Split long animations into multiple scenes
7. Use the editor: Real-time preview with scrubbing is invaluable

When to Use Motion Canvas vs Remotion

	Motion Canvas	Remotion
Best for	Educational, explainer	Product, marketing
Animation style	Imperative (generators)	Declarative (React)
Editor	Built-in real-time	Remotion Studio
Code animation	First-class support	Manual implementation
Ecosystem	Growing	Large (npm packages)
Voice sync	Built-in audio sync	Manual sync

Source

• Repo: github.com/motion-canvas/motion-canvas
• Docs: motioncanvas.io/docs
• Examples: motioncanvas.io/docs/examples