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Class: Scene

Defined in: core/Scene.ts:68

Scene orchestrator for manimweb. Manages the renderer, camera, mobjects, and animation playback. Works like Manim's Scene class - add mobjects, play animations.

Extended by​

Constructors​

Constructor​

new Scene(container, options): Scene

Defined in: core/Scene.ts:112

Create a new Scene.

Parameters​

container​

HTMLElement

DOM element to render into

options​

SceneOptions = {}

Scene configuration options

Returns​

Scene

Properties​

_autoRender​

protected _autoRender: boolean = true

Defined in: core/Scene.ts:96

_disposed​

protected _disposed: boolean = false

Defined in: core/Scene.ts:80

_waitCleanups​

protected _waitCleanups: () => void[] = []

Defined in: core/Scene.ts:81

Returns​

void

Accessors​

_hasActiveLoop​

Get Signature​

get protected _hasActiveLoop(): boolean

Defined in: core/Scene.ts:219

Whether a render loop is active (play() or wait()). Used by ThreeDScene to avoid duplicate orbit rAF loops.

Returns​

boolean

audioManager​

Get Signature​

get audioManager(): AudioManager

Defined in: core/Scene.ts:245

Get the audio manager (lazily created on first access). Use this to access lower-level audio controls.

Returns​

AudioManager

backgroundOpacity​

Get Signature​

get backgroundOpacity(): number

Defined in: core/Scene.ts:1040

Get the background opacity (0 = fully transparent, 1 = fully opaque).

Returns​

number

Set Signature​

set backgroundOpacity(value): void

Defined in: core/Scene.ts:1048

Set the background opacity (0 = fully transparent, 1 = fully opaque). Only effective if the scene was created with backgroundOpacity < 1.

Parameters​
value​

number

Returns​

void

camera​

Get Signature​

get camera(): Camera2D

Defined in: core/Scene.ts:181

Get the camera.

Returns​

Camera2D

currentTime​

Get Signature​

get currentTime(): number

Defined in: core/Scene.ts:226

Get the current playback time.

Returns​

number

isPlaying​

Get Signature​

get isPlaying(): boolean

Defined in: core/Scene.ts:211

Get whether animations are currently playing.

Returns​

boolean

mobjects​

Get Signature​

get mobjects(): ReadonlySet<Mobject>

Defined in: core/Scene.ts:233

Get all mobjects in the scene.

Returns​

ReadonlySet<Mobject>

renderer​

Get Signature​

get renderer(): Renderer

Defined in: core/Scene.ts:188

Get the renderer.

Returns​

Renderer

stateManager​

Get Signature​

get stateManager(): SceneStateManager

Defined in: core/Scene.ts:1067

Get the scene's state manager for advanced undo/redo control.

Returns​

SceneStateManager

threeScene​

Get Signature​

get threeScene(): Scene

Defined in: core/Scene.ts:174

Get the Three.js scene.

Returns​

Scene

timeline​

Get Signature​

get timeline(): Timeline

Defined in: core/Scene.ts:195

Get the current timeline.

Returns​

Timeline

Methods​

_needsPerFrameRendering()​

protected _needsPerFrameRendering(): boolean

Defined in: core/Scene.ts:738

Whether the scene needs per-frame rendering during wait(). Returns true if any mobject has updaters. Subclasses (e.g. ThreeDScene) can override to also check for ambient camera rotation, etc.

Returns​

boolean

_render()​

protected _render(): void

Defined in: core/Scene.ts:750

Render a single frame. Syncs only dirty mobjects before rendering for performance. Protected so subclasses (e.g. ZoomedScene) can override for multi-pass rendering.

Returns​

void

add()​

add(...mobjects): this

Defined in: core/Scene.ts:321

Add mobjects to the scene.

Parameters​

mobjects​

...Mobject[]

Mobjects to add

Returns​

this

addForegroundMobject()​

addForegroundMobject(...mobjects): this

Defined in: core/Scene.ts:298

Add mobjects as foreground objects that render on top of everything. Matches Manim Python's add_foreground_mobject().

Parameters​

mobjects​

...Mobject[]

Mobjects to add in the foreground

Returns​

this

addSound()​

addSound(url, options?): Promise<AudioTrack>

Defined in: core/Scene.ts:266

Add a sound to play at a specific time on the timeline. Mirrors Python manim's self.add_sound("file.wav", time_offset=0.5).

Parameters​

url​

string

URL of the audio file

options?​

AddSoundOptions

Scheduling and playback options

Returns​

Promise<AudioTrack>

Promise resolving to the created AudioTrack

Example​

await scene.addSound('/sounds/click.wav', { time: 0.5 });
await scene.addSound('/sounds/whoosh.wav');  // plays at time 0

addSoundAtAnimation()​

addSoundAtAnimation(animation, url, options?): Promise<AudioTrack>

Defined in: core/Scene.ts:285

Add a sound that starts when a given animation begins.

Parameters​

animation​

Animation

The animation to sync with

url​

string

URL of the audio file

options?​

Omit<AddSoundOptions, "time"> & object

Additional options (timeOffset shifts relative to animation start)

Returns​

Promise<AudioTrack>

Promise resolving to the created AudioTrack

Example​

const fadeIn = new FadeIn(circle);
await scene.addSoundAtAnimation(fadeIn, '/sounds/appear.wav');
await scene.play(fadeIn);

batch()​

batch(callback): void

Defined in: core/Scene.ts:942

Batch multiple mobject updates without re-rendering between each. Useful for performance when making many changes at once.

Parameters​

callback​

() => void

Function containing multiple mobject operations

Returns​

void

Example​

scene.batch(() => {
  circle.setColor('red');
  circle.shift([1, 0, 0]);
  square.setOpacity(0.5);
});

clear()​

clear(__namedParameters): this

Defined in: core/Scene.ts:420

Clear all mobjects from the scene.

Parameters​

__namedParameters​
render?​

boolean = true

Returns​

this

dispose()​

dispose(): void

Defined in: core/Scene.ts:1220

Clean up all resources (renderer, mobjects, audio).

Returns​

void

export()​

export(filename, options?): Promise<Blob>

Defined in: core/Scene.ts:1176

Export the scene animation as a file (GIF or video). Format is inferred from the filename extension.

Supported extensions:

  • .gif - Animated GIF
  • .webm - WebM video (VP9)
  • .mp4 - MP4 video (browser codec support varies)
  • .mov - QuickTime video (browser codec support varies)

Parameters​

filename​

string

Output filename (e.g. 'animation.gif', 'scene.webm')

options?​

SceneExportOptions

Export options (fps, quality, dimensions, etc.)

Returns​

Promise<Blob>

The exported Blob

Example​

// Export as GIF
const blob = await scene.export('animation.gif');

// Export as WebM with custom options
const blob = await scene.export('scene.webm', {
  fps: 30,
  quality: 0.8,
  onProgress: (p) => console.log(`${Math.round(p * 100)}%`),
});

getCanvas()​

getCanvas(): HTMLCanvasElement

Defined in: core/Scene.ts:1004

Get the canvas element.

Returns​

HTMLCanvasElement

The HTMLCanvasElement used for rendering

getContainer()​

getContainer(): HTMLElement

Defined in: core/Scene.ts:1013

Get the container element the scene is rendered into. Returns the parent element of the canvas.

Returns​

HTMLElement

The container HTMLElement

getHeight()​

getHeight(): number

Defined in: core/Scene.ts:1033

Get the height of the canvas in pixels.

Returns​

number

Canvas height in pixels

getState()​

getState(label?): SceneSnapshot

Defined in: core/Scene.ts:1121

Get a snapshot of the current scene state without modifying stacks.

Parameters​

label?​

string

Returns​

SceneSnapshot

getTargetFps()​

getTargetFps(): number

Defined in: core/Scene.ts:968

Get the current target frame rate.

Returns​

number

Target fps

getTimelineDuration()​

getTimelineDuration(): number

Defined in: core/Scene.ts:1056

Get the total duration of the current timeline.

Returns​

number

Duration in seconds, or 0 if no timeline

getWidth()​

getWidth(): number

Defined in: core/Scene.ts:1025

Get the width of the canvas in pixels.

Returns​

number

Canvas width in pixels

isInView()​

isInView(object): boolean

Defined in: core/Scene.ts:791

Check if an object is within the camera's view frustum. Useful for manual culling checks or debugging.

Parameters​

object​

Object3D

Three.js object to check

Returns​

boolean

true if object is in view or if culling is disabled

pause()​

pause(): this

Defined in: core/Scene.ts:653

Pause playback (video and audio).

Returns​

this

play()​

play(...animations): Promise<void>

Defined in: core/Scene.ts:462

Play animations in parallel (all at once). Matches Manim's scene.play() behavior where multiple animations run simultaneously. Automatically adds mobjects to the scene if not already present.

Parameters​

animations​

...Animation[]

Animations to play

Returns​

Promise<void>

Promise that resolves when all animations complete

playAll()​

playAll(...animations): Promise<void>

Defined in: core/Scene.ts:531

Play multiple animations in parallel (all at once). Alias for play() - delegates to play() to avoid duplicated logic.

Parameters​

animations​

...Animation[]

Animations to play simultaneously

Returns​

Promise<void>

Promise that resolves when all animations complete

redo()​

redo(): boolean

Defined in: core/Scene.ts:1110

Redo the last undone change. The current state is pushed to the undo stack.

Returns​

boolean

true if redo was applied, false if nothing to redo

remove()​

remove(...mobjects): this

Defined in: core/Scene.ts:366

Remove mobjects from the scene.

Parameters​

mobjects​

...Mobject[]

Mobjects to remove

Returns​

this

render()​

render(): void

Defined in: core/Scene.ts:1140

Force render a single frame. Useful for video export where frames need to be captured at specific times.

Returns​

void

resize()​

resize(width, height): this

Defined in: core/Scene.ts:986

Handle window resize.

Parameters​

width​

number

New width in pixels

height​

number

New height in pixels

Returns​

this

resume()​

resume(): this

Defined in: core/Scene.ts:667

Resume playback (video and audio).

Returns​

this

saveState()​

saveState(label?): SceneSnapshot

Defined in: core/Scene.ts:1086

Save the current state of all scene mobjects. Pushes onto the undo stack and clears the redo stack.

Parameters​

label?​

string

Optional human-readable label

Returns​

SceneSnapshot

The captured SceneSnapshot

Example​

scene.add(circle, square);
scene.saveState();
circle.shift([2, 0, 0]);
scene.undo(); // circle returns to original position

seek()​

seek(time): this

Defined in: core/Scene.ts:638

Seek to a specific time in the timeline. Also seeks the audio manager if audio has been used.

Parameters​

time​

number

Time in seconds

Returns​

this

setFrustumCulling()​

setFrustumCulling(enabled): this

Defined in: core/Scene.ts:976

Enable or disable frustum culling.

Parameters​

enabled​

boolean

Whether frustum culling should be enabled

Returns​

this

setState()​

setState(snapshot): void

Defined in: core/Scene.ts:1129

Apply a previously captured snapshot, overwriting all mobject states. Does NOT modify undo/redo stacks. Call saveState() first to preserve.

Parameters​

snapshot​

SceneSnapshot

Returns​

void

setTargetFps()​

setTargetFps(fps): this

Defined in: core/Scene.ts:958

Set the target frame rate.

Parameters​

fps​

number

Target frames per second (1-120)

Returns​

this

stop()​

stop(): this

Defined in: core/Scene.ts:682

Stop playback and reset timeline (video and audio).

Returns​

this

undo()​

undo(): boolean

Defined in: core/Scene.ts:1096

Undo the last change (restore the most recently saved state). The current state is pushed to the redo stack.

Returns​

boolean

true if undo was applied, false if nothing to undo

wait()​

wait(duration): Promise<void>

Defined in: core/Scene.ts:541

Wait for a duration (pause between animations). Runs a render loop during the wait so that updaters keep ticking.

Parameters​

duration​

number = 1

Duration in seconds

Returns​

Promise<void>

Promise that resolves after the duration