Class: ValueTracker

Returns

Mobject._getEdgeInDirection

World-space edge position (center + half-bounding-box offset).

Inherited from

_localToWorld()

protected _localToWorld(p): Vector3Tuple

Defined in: core/Mobject.ts:387

LOCAL point -> WORLD (the frame this node's points live in; this node's own transform IS applied).

Parameters

p

Returns

Mobject._localToWorld

Post

result === this._worldMatrix() * p

Inherited from

_markDirty()

_markDirty(): void

Defined in: core/Mobject.ts:920

Mark this node's render/transform state stale and propagate the flag to the root. World-space geometry of any node depends on its ancestors' transforms, so a change anywhere must invalidate the whole ancestor chain; the invariant "a clean node has a clean subtree" then lets _syncToThree()/root-sync skip untouched branches safely.

Returns

void

Post

this._dirty && (this.parent => this.parent._dirty)

Inherited from

Mobject._markDirty

_markDirtyUpward()

_markDirtyUpward(): void

Defined in: core/Mobject.ts:931

Alias for _markDirty. Retained as the single override point for subclasses (e.g. VMobject) that must also invalidate baked geometry when a mutation propagates upward; transform-only changes call _markDirty() directly.

Returns

void

Inherited from

Mobject._markDirtyUpward

_normalizeChildrenInto()

protected _normalizeChildrenInto(worldMatrix): void

Defined in: core/Mobject.ts:836

Recurse normalizeTransform into children, composing each child's own matrix onto worldMatrix so every descendant flattens into the same frame.

Parameters

worldMatrix

Matrix4

Returns

void

Inherited from

Mobject._normalizeChildrenInto

_ownMatrix()

_ownMatrix(): Matrix4

Defined in: core/Mobject.ts:969

This node's transform matrix in isolation — position, rotation, and scale composed together, with no ancestor contribution.

Returns

Matrix4

Post

this.parent === null => this._computeWorldMatrix() === this._computeOwnMatrix()

Post

this.parent !== null => this._computeWorldMatrix() === this.parent._computeWorldMatrix() * this._computeOwnMatrix()

Inherited from

Mobject._ownMatrix

_root()

_root(): Mobject

Defined in: core/Mobject.ts:940

The topmost ancestor (the node with no parent).

Returns

Inherited from

Mobject._root

_rotateAboutParentLocalPoint()

protected _rotateAboutParentLocalPoint(angle, axis, pivotLocal): void

Defined in: core/Mobject.ts:356

Rotate about a pivot expressed in this node's PARENT-local frame (the same frame as this.position). No world-space conversion is done.

Parameters

angle

number

axis

pivotLocal

Mobject._rotateAboutParentLocalPoint

Returns

void

Pre

pivotLocal is in the same frame as this.position (parent-local)

Post

the parent-local pivot point is fixed; this.position rotates about it

Post

this.rotation === old.rotation composed with the requested rotation

Inherited from

_syncMaterialToThree()

protected _syncMaterialToThree(): void

Defined in: core/Mobject.ts:892

Returns

void

Inherited from

Mobject._syncMaterialToThree

_syncToThree()

_syncToThree(): void

Defined in: core/Mobject.ts:870

Returns

void

Inherited from

Mobject._syncToThree

_syncWorldMatrices()

_syncWorldMatrices(): Object3D

Defined in: core/Mobject.ts:661

Refresh the THREE world matrices so a geometry query reads current transforms, and return the backing object. World coordinates depend on every ancestor's transform, so we sync from the root (the dirty invariant — see _markDirty — lets the recursion skip clean subtrees). _syncToThree only copies locals onto the THREE objects; setFromObject won't walk up to refresh matrixWorld, so we flush ancestors (true) and descendants (true) here. Shared by getBounds() and getBoundingBox() so both stay consistent.

Returns

Object3D

Pre

!this.isEmpty()

Post

result.min <= result.max component-wise

Inherited from

Mobject._syncWorldMatrices

_worldMatrix()

_worldMatrix(): Matrix4

Defined in: core/Mobject.ts:974

Returns

Matrix4

Inherited from

Mobject._worldMatrix

_worldToLocal()

protected _worldToLocal(p): Vector3Tuple

Defined in: core/Mobject.ts:397

WORLD point -> this node's LOCAL frame. Inverse of _localToWorld.

Parameters

p

Returns

Mobject._worldToLocal

Post

result === this._worldMatrix().invert() * p

Inherited from

add()

add(...mobjects): this

Defined in: core/Mobject.ts:481

Parameters

mobjects

...Mobject[]

Returns

this

Inherited from

Mobject.add

addUpdater()

addUpdater(updater, callOnAdd): this

Defined in: core/Mobject.ts:1010

Parameters

updater

UpdaterFunction

callOnAdd

boolean = false

Returns

this

Inherited from

Mobject.addUpdater

alignTo()

alignTo(target, direction): this

Defined in: core/Mobject.ts:713

Parameters

target

direction

Returns

this

Inherited from

Mobject.alignTo

animateTo()

animateTo(targetValue, options?): Animation

Defined in: mobjects/value-tracker/ValueTracker.ts:144

Create an animation that smoothly changes the value.

Parameters

targetValue

number

The value to animate to

options?

AnimationOptions

Animation options (duration, rateFunc, etc.)

Returns

Animation

An animation that can be added to a timeline

Example

// Animate from current value to 10 over 2 seconds
timeline.add(tracker.animateTo(10, { duration: 2 }));

// Animate with custom rate function
timeline.add(tracker.animateTo(5, {
  duration: 1.5,
  rateFunc: easeInOut
}));

applyFunction()

applyFunction(fn, options?): this

Defined in: core/Mobject.ts:1068

Parameters

fn

(point) => number[]

options?

aboutEdge?

aboutPoint?

Mobject.applyFunction

Returns

this

Inherited from

applyFunctionAboutPoint()

applyFunctionAboutPoint(fn, aboutPoint): this

Defined in: core/Mobject.ts:1047

Apply a function to every descendant's world-space points, about a given point. Recurses the family and delegates to _applyFunctionAboutPoint on each node.

Parameters

fn

(pts) => number[][]

aboutPoint

number[] = ...

Returns

this

Pre

fn(pts).length === pts.length

Post

m.getPoints()[i] === old.m.getPoints().map(p => fn([p - aboutPoint]) + aboutPoint)[i] // for every descendant m

Inherited from

Mobject.applyFunctionAboutPoint

applyMatrix()

applyMatrix(matrix, options?): this

Defined in: core/Mobject.ts:1076

Parameters

matrix

number[][]

options?

aboutEdge?

aboutPoint?

Mobject.applyToFamily

Returns

this

Inherited from

Mobject.applyMatrix

applyToFamily()

applyToFamily(func): this

Defined in: core/Mobject.ts:998

Parameters

func

(mobject) => void

Returns

this

Inherited from

become()

become(other): this

Defined in: core/Mobject.ts:592

Parameters

other

Mobject.clearUpdaters

Returns

this

Inherited from

Mobject.become

center()

center(): this

Defined in: core/Mobject.ts:772

Returns

this

Inherited from

Mobject.center

clearUpdaters()

clearUpdaters(): this

Defined in: core/Mobject.ts:1022

Returns

this

Inherited from

copy()

copy(): ValueTracker

Defined in: mobjects/value-tracker/ValueTracker.ts:160

Create a copy of this ValueTracker.

Returns

ValueTracker

A new ValueTracker with the same value

Overrides

Mobject.copy

disableChildZLayering()

disableChildZLayering(): this

Defined in: core/Mobject.ts:905

Disable the 2D draw-order z-layering offset (idx * 0.01 per non-first child, applied in _syncToThree) for this node and its whole subtree.

The offset is a flat-2D hack that fakes paint order by nudging later siblings toward the camera. Under a 3D perspective camera with real depth sorting it instead corrupts geometry: a group's children drift along world-z proportionally to their index (issue #465). ThreeDScene calls this on every added mobject so 3D scenes opt out. Because the offset is gated on the parent's flag, setting it on a container also covers children added later.

Returns

this

Inherited from

Mobject.disableChildZLayering

dispose()

dispose(): void

Defined in: core/Mobject.ts:1117

Returns

void

Inherited from

Mobject.dispose

flip()

flip(axis, options?): this

Defined in: core/Mobject.ts:403

Parameters

axis

Vector3Tuple = ...

options?

aboutEdge?

aboutPoint?

Returns

this

Inherited from

Mobject.flip

generateTarget()

generateTarget(): Mobject

Defined in: core/Mobject.ts:1091

Returns

Mobject.generateTarget

Inherited from

getBottom()

getBottom(): Vector3Tuple

Defined in: core/Mobject.ts:751

Returns

Mobject.getBoundingBox

Inherited from

Mobject.getBottom

getBoundingBox()

getBoundingBox(): object

Defined in: core/Mobject.ts:732

Returns

object

depth

depth: number

height

height: number

width

width: number

Inherited from

getBounds()

getBounds(): object

Defined in: core/Mobject.ts:679

World-space axis-aligned bounding box.

Uses Box3.setFromObject() via the Three.js subtree. This works for all standard geometry types without a renderer. VMobject overrides this with point math because Line2's LineGeometry is incompatible with Box3.setFromObject() — see PointBounds.ts for the full explanation.

Returns

object

max

max: object

max.x

x: number

max.y

y: number

max.z

z: number

min

min: object

min.x

x: number

min.y

y: number

min.z

z: number

Pre

!this.isEmpty()

Post

result.min <= result.max component-wise

Inherited from

Mobject.getBounds

getCenter()

getCenter(): Vector3Tuple

Defined in: mobjects/value-tracker/ValueTracker.ts:152

Get the center position (returns origin since this is invisible).

Returns

Mobject.getDisplayMeshes

[0, 0, 0]

Overrides

Mobject.getCenter

getDisplayMeshes()

getDisplayMeshes(): Mesh<BufferGeometry<NormalBufferAttributes, BufferGeometryEventMap>, Material<MaterialEventMap> | Material<MaterialEventMap>[], Object3DEventMap>[]

Defined in: core/Mobject.ts:990

Returns

Mesh<BufferGeometry<NormalBufferAttributes, BufferGeometryEventMap>, Material<MaterialEventMap> | Material<MaterialEventMap>[], Object3DEventMap>[]

Inherited from

getDisplayMeshLength()

getDisplayMeshLength(): number

Defined in: core/Mobject.ts:986

Number of visible display meshes this mobject contributes when rendered. Used for Transform eligibility checks without forcing Three.js object creation.

Returns

number

Inherited from

Mobject.getDisplayMeshLength

getEdge()

getEdge(direction): Vector3Tuple

Defined in: core/Mobject.ts:745

Parameters

getFamily()

getFamily(): Mobject[]

Defined in: core/Mobject.ts:1004

Returns

Mobject[]

Inherited from

Mobject.getFamily

getHeight()

getHeight(): number

Defined in: core/Mobject.ts:738

Returns

number

Inherited from

Mobject.getHeight

getLeft()

getLeft(): Vector3Tuple

Defined in: core/Mobject.ts:754

Returns

Inherited from

Mobject.getLeft

getLocalCenter()

getLocalCenter(): Vector3Tuple

Defined in: core/Mobject.ts:643

Get center in this mobject's parent coordinate frame.

Includes this node's own local transform, excludes ancestor transforms.

Returns

Mobject.getLocalCenter

Post

this.parent === null => result === this.getCenter()

Post

this.parent !== null => result === parent._computeWorldMatrix().invert() * this.getCenter()

Inherited from

getRight()

getRight(): Vector3Tuple

Defined in: core/Mobject.ts:757

Returns

Mobject.getThreeObject

Inherited from

Mobject.getRight

getThreeObject()

getThreeObject(): Object3D

Defined in: core/Mobject.ts:944

Returns

Object3D

Inherited from

getTop()

getTop(): Vector3Tuple

Defined in: core/Mobject.ts:748

Returns

Mobject.isTransformNormalized

Inherited from

Mobject.getTop

getUpdaters()

getUpdaters(): UpdaterFunction[]

Defined in: core/Mobject.ts:1029

Returns

UpdaterFunction[]

Inherited from

Mobject.getUpdaters

getValue()

getValue(): number

Defined in: mobjects/value-tracker/ValueTracker.ts:100

Get the current value.

Returns

number

The current tracked value

getWidth()

getWidth(): number

Defined in: core/Mobject.ts:735

Returns

number

Inherited from

Mobject.getWidth

hasUpdaters()

hasUpdaters(): boolean

Defined in: core/Mobject.ts:1026

Returns

boolean

Inherited from

Mobject.hasUpdaters

incrementValue()

incrementValue(amount): this

Defined in: mobjects/value-tracker/ValueTracker.ts:122

Increment the value by a given amount.

Parameters

amount

number

The amount to add (can be negative)

Returns

this

this for chaining

isEmpty()

isEmpty(): boolean

Defined in: core/Mobject.ts:611

Whether this mobject has no renderable geometry. Base default is conservative: non-empty unless specialized subclasses decide otherwise.

Returns

boolean

Inherited from

Mobject.isEmpty

isTransformNormalized()

isTransformNormalized(): boolean

Defined in: core/Mobject.ts:517

Check if this mobject's transform is normalized (rotation=0, scale=1).

Returns

boolean

Post

result === (rotation.x==0 && rotation.y==0 && rotation.z==0 && scaleVector===[1,1,1])

Inherited from

moveTo()

moveTo(target, alignedEdge?): this

Defined in: core/Mobject.ts:256

Move to target position in world space.

Computes the delta from the current world-space center, converts it into this node's parent-local frame (the frame shift()/position live in), and applies it so the world-space center lands on the target. The parent-local conversion is what makes this correct when the node is parented under a scaled/rotated parent — a raw world delta fed to shift() would be scaled/rotated by the parent. For an unparented node the conversion is the identity, so behavior is unchanged.

Parameters

target

alignedEdge?

Returns

this

Post

result world center === target (within the parent's representable frame)

Pre

!this.isEmpty() if needed (e.g., VGroup).

Inherited from

Mobject.moveTo

moveToAligned()

moveToAligned(target, alignedEdge?): this

Defined in: core/Mobject.ts:723

Parameters

target

alignedEdge?

Mobject.moveToAligned

Returns

this

Inherited from

nextTo()

nextTo(target, direction, buff): this

Defined in: core/Mobject.ts:696

Parameters

target

Mobject.normalizeTransform

direction

Vector3Tuple = RIGHT

buff

number = 0.25

Returns

this

Inherited from

Mobject.nextTo

normalizeTransform()

normalizeTransform(worldMatrix): this

Defined in: mobjects/value-tracker/ValueTracker.ts:72

Flatten this mobject's transform into its canonical, absolute representation.

Bakes worldMatrix into the node's own geometry, recurses so every descendant is expressed in the same frame, then resets the local transform to identity. Called with no argument it seeds with this node's OWN matrix, so bake-then-reset preserves world appearance whether or not the node has ancestors — the ancestors keep their transforms and still apply. The recursion (and a detached-clone caller) passes an explicit accumulated matrix.

Implemented per family rather than via a hook so the compiler forces every geometry-owning subclass to declare how it flattens: containers reset to identity (geometry lives in children), point-based mobjects bake worldMatrix into their points, and Three.js meshes — which cannot bake into points — absolutize their local transform instead (see _flattenAsMesh).

Parameters

worldMatrix

Matrix4 = ...

Returns

this

Post

old.getPoints()[i] === this.getPoints()[i] // world geometry preserved, every descendant

Post

this._computeOwnMatrix() === Identity // container/point nodes; meshes: own === worldMatrix

Overrides

prepareForNonlinearTransform()

prepareForNonlinearTransform(numPieces): this

Defined in: core/Mobject.ts:1084

Parameters

numPieces

number = 50

Returns

this

Inherited from

Mobject.prepareForNonlinearTransform

remove()

remove(...mobjects): this

Defined in: core/Mobject.ts:496

Parameters

mobjects

...Mobject[]

Returns

this

Inherited from

Mobject.remove

removeUpdater()

removeUpdater(updater): this

Defined in: core/Mobject.ts:1016

Parameters

updater

UpdaterFunction

Returns

this

Inherited from

Mobject.removeUpdater

replace()

replace(target, stretch): this

Defined in: core/Mobject.ts:597

Parameters

target

Mobject.rotateAboutOrigin

stretch

boolean = false

Returns

this

Inherited from

Mobject.replace

restoreState()

restoreState(): boolean

Defined in: core/Mobject.ts:1101

Returns

boolean

Inherited from

Mobject.restoreState

rotate()

rotate(angle, axisOrOptions?): this

Defined in: core/Mobject.ts:306

Rotate the mobject by angle around an axis. Accepts aboutPoint or aboutEdge to specify the rotation center.

Parameters

angle

number

axisOrOptions?

Vector3Tuple | AxisOrOptions

Returns

this

Inherited from

Mobject.rotate

rotateAboutOrigin()

rotateAboutOrigin(angle, axis): this

Defined in: core/Mobject.ts:344

Parameters

angle

number

axis

Vector3Tuple = ...

Returns

this

Inherited from

saveState()

saveState(): this

Defined in: core/Mobject.ts:1096

Returns

this

Inherited from

Mobject.saveState

scale()

scale(factor, options?): this

Defined in: core/Mobject.ts:429

Parameters

factor

number | Vector3Tuple

options?

aboutEdge?

aboutPoint?

Mobject.setFillOpacity

Returns

this

Inherited from

Mobject.scale

setColor()

setColor(color): this

Defined in: core/Mobject.ts:166

Parameters

color

string

Returns

this

Inherited from

Mobject.setColor

setFill()

setFill(color?, opacity?): this

Defined in: core/Mobject.ts:204

Parameters

color?

string

opacity?

number

Returns

this

Inherited from

Mobject.setFill

setFillOpacity()

setFillOpacity(opacity): this

Defined in: core/Mobject.ts:194

Parameters

opacity

number

Returns

this

Inherited from

setStrokeOpacity()

setStrokeOpacity(opacity): this

Defined in: core/Mobject.ts:174

Parameters

opacity

number

Returns

this

Inherited from

Mobject.setStrokeOpacity

setStrokeWidth()

setStrokeWidth(width): this

Defined in: core/Mobject.ts:184

Parameters

width

number

Returns

this

Inherited from

Mobject.setStrokeWidth

setStyle()

setStyle(style): this

Defined in: core/Mobject.ts:152

Parameters

style

Partial<MobjectStyle>

Returns

this

Inherited from

Mobject.setStyle

setValue()

setValue(value): this

Defined in: mobjects/value-tracker/ValueTracker.ts:109

Set the value directly (without animation).

Parameters

value

number

The new value

Returns

this

this for chaining

setX()

setX(x): this

Defined in: core/Mobject.ts:760

Parameters

x

number

Returns

this

Inherited from

Mobject.setX

setY()

setY(y): this

Defined in: core/Mobject.ts:764

Parameters

y

number

Returns

this

Inherited from

Mobject.setY

setZ()

setZ(z): this

Defined in: core/Mobject.ts:768

Parameters

z

number

Returns

this

Inherited from

Mobject.setZ

shift()

shift(delta): this

Defined in: core/Mobject.ts:234

Parameters

delta

Returns

this

Inherited from

Mobject.shift

stretch()

stretch(factor, dim, options?): this

Defined in: core/Mobject.ts:461

Parameters

factor

number

dim

number

options?

aboutEdge?

aboutPoint?

Returns

this

Inherited from

Mobject.stretch

toCorner()

toCorner(direction, buff, frameDimensions?): this

Defined in: core/Mobject.ts:801

Parameters

direction

Vector3Tuple = ...

buff

number = 0.5

frameDimensions?

[number, number]

Returns

this

Inherited from

Mobject.toCorner

toEdge()

toEdge(direction, buff, frameDimensions?): this

Defined in: core/Mobject.ts:796

Parameters

direction