Theatre.js Best Practices Skill

Theatre.js Best Practices

Motion design editor and animation library for the web. Provides a visual timeline editor (Studio) with programmatic control.

Installation

# Core + Studio (development)
npm install @theatre/core@0.7 @theatre/studio@0.7

# React Three Fiber integration
npm install @theatre/r3f@0.7

# React utilities
npm install @theatre/react

# Theatric (simplified controls)
npm install theatric

Quick Start

import * as core from '@theatre/core'
import studio from '@theatre/studio'

// Initialize Studio (dev only)
if (import.meta.env.DEV) {
  studio.initialize()
}

// Create project → sheet → object
const project = core.getProject('My Project')
const sheet = project.sheet('Main')
const obj = sheet.object('Box', {
  position: { x: 0, y: 0 },
  opacity: 1
})

// Read values
console.log(obj.value.position.x)

// Listen to changes
obj.onValuesChange((values) => {
  element.style.opacity = values.opacity
  element.style.transform = `translate(${values.position.x}px, ${values.position.y}px)`
})

// Play animation
sheet.sequence.play({ iterationCount: Infinity })

Core Concepts

| Concept | Description | |---------|-------------| | Project | Container for all animation data; maps to exported JSON state | | Sheet | A scene or component; contains objects and one sequence | | Object | Animatable entity with typed props | | Sequence | Timeline with keyframes; controls playback | | Props | Typed values (number, compound, rgba, etc.) |

Reference Index

| Reference | Use When | |-----------|----------| | references/01-core.md | Project setup, sheets, objects, sequences, playback control | | references/02-prop-types.md | Defining props, custom types, compound props, constraints | | references/03-studio.md | Studio UI, keyboard shortcuts, extensions, panels | | references/04-react-integration.md | useVal, usePrism, @theatre/react hooks | | references/05-r3f-integration.md | React Three Fiber, editable components, SheetProvider | | references/06-production.md | Export state, assets, deployment, tree-shaking |

Common Patterns

Animate DOM Element

const obj = sheet.object('Card', {
  x: 0,
  y: 0,
  rotation: 0,
  scale: 1,
  opacity: 1
})

obj.onValuesChange(({ x, y, rotation, scale, opacity }) => {
  element.style.transform = `translate(${x}px, ${y}px) rotate(${rotation}deg) scale(${scale})`
  element.style.opacity = opacity
})

Sequence Playback Control

const seq = sheet.sequence

// Play once
seq.play()

// Play with options
seq.play({
  iterationCount: Infinity,  // loop forever
  range: [0, 2],             // play seconds 0-2
  rate: 1.5,                 // 1.5x speed
  direction: 'alternate'     // ping-pong
})

// Pause and seek
seq.pause()
seq.position = 1.5  // jump to 1.5s

// Await completion
await seq.play({ iterationCount: 1 })
console.log('Animation complete')

React Three Fiber Scene

import { Canvas } from '@react-three/fiber'
import { editable as e, SheetProvider } from '@theatre/r3f'
import { getProject } from '@theatre/core'
import studio from '@theatre/studio'
import extension from '@theatre/r3f/dist/extension'

// Dev setup
if (import.meta.env.DEV) {
  studio.initialize()
  studio.extend(extension)
}

const sheet = getProject('R3F Demo').sheet('Scene')

function App() {
  return (
    <Canvas>
      <SheetProvider sheet={sheet}>
        <e.mesh theatreKey="Cube">
          <boxGeometry />
          <meshStandardMaterial color="orange" />
        </e.mesh>
        <e.pointLight theatreKey="Light" position={[10, 10, 10]} />
      </SheetProvider>
    </Canvas>
  )
}

Theatric Controls (Simple)

import { useControls, types } from 'theatric'

function Component() {
  const { color, intensity, position } = useControls({
    color: '#ff0000',
    intensity: types.number(1, { range: [0, 2] }),
    position: { x: 0, y: 0, z: 0 }
  })

  return <mesh position={[position.x, position.y, position.z]} />
}

Critical Mistakes to Avoid

1. Studio in Production

// ❌ Includes studio in bundle
import studio from '@theatre/studio'
studio.initialize()

// ✅ Dev-only initialization
if (import.meta.env.DEV) {
  studio.initialize()
}

2. Missing State in Production

// ❌ No animations without state
const project = core.getProject('My Project')

// ✅ Load exported state
import state from './state.json'
const project = core.getProject('My Project', { state })

3. Object Key Collisions

// ❌ Same key = same object (shared state)
sheet.object('Box', { x: 0 })
sheet.object('Box', { y: 0 })  // Overwrites!

// ✅ Unique keys per object
sheet.object('Box1', { x: 0 })
sheet.object('Box2', { y: 0 })

4. Missing R3F Extension

// ❌ No 3D controls in Studio
studio.initialize()

// ✅ Extend with R3F extension
import extension from '@theatre/r3f/dist/extension'
studio.initialize()
studio.extend(extension)

5. Forgetting theatreKey

// ❌ Not editable
<e.mesh>

// ✅ Requires theatreKey
<e.mesh theatreKey="MyCube">

Quick Reference

| Task | Solution | |------|----------| | Create project | getProject('Name', { state? }) | | Create sheet | project.sheet('Name') | | Create object | sheet.object('Key', { props }) | | Listen to values | obj.onValuesChange(cb) | | Read value | obj.value.propName | | Play animation | sheet.sequence.play(opts?) | | Pause animation | sheet.sequence.pause() | | Seek position | sheet.sequence.position = 1.5 | | R3F editable | <e.mesh theatreKey="Key"> | | React value hook | useVal(obj.props.x) | | Export state | Studio → Project → Export (JSON) |

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