Documentation / scene / AnimationTrack

Abstract Class: AnimationTrack<StateType>

Defined in: libs/scene/src/animation/animationtrack.ts:19

Base class for animation tracks.

A track produces time-varying state for a specific target and defines how to:

• Compute state at a given time (calculateState)
• Apply that state to a target (applyState)
• Blend between two states (mixState)
• Report its blend compatibility (getBlendId)
• Report its intrinsic duration (getDuration)

Generic:

• StateType is the shape of the computed/applied state (e.g., number, vector, pose).

Extended by

• NodeTranslationTrack
• NodeRotationTrack
• NodeEulerRotationTrack
• NodeScaleTrack
• PropertyTrack
• MorphTargetTrack
• MorphTargetGroupTrack
• FixedGeometryCacheTrack
• PCAGeometryCacheTrack

Type Parameters

StateType

StateType = unknown

Constructors

Constructor

new AnimationTrack<StateType>(embedded?): AnimationTrack<StateType>

Defined in: libs/scene/src/animation/animationtrack.ts:35

Construct a new animation track.

Parameters

embedded?

boolean

Whether this track is embedded/owned inline by its container. Default false.

Returns

AnimationTrack<StateType>

Accessors

name

Get Signature

get name(): string

Defined in: libs/scene/src/animation/animationtrack.ts:45

Human-readable name of the track.

Returns

string

Set Signature

set name(val): void

Defined in: libs/scene/src/animation/animationtrack.ts:48

Parameters

val

string

Returns

void

---

embedded

Get Signature

get embedded(): boolean

Defined in: libs/scene/src/animation/animationtrack.ts:54

Whether this track is embedded (owned inline by a resource/container).

Returns

boolean

---

animation

Get Signature

get animation(): AnimationClip

Defined in: libs/scene/src/animation/animationtrack.ts:60

The AnimationClip that owns this track.

Returns

AnimationClip

Set Signature

set animation(ani): void

Defined in: libs/scene/src/animation/animationtrack.ts:63

Parameters

ani

AnimationClip

Returns

void

---

target

Get Signature

get target(): string

Defined in: libs/scene/src/animation/animationtrack.ts:72

Logical target identifier for this track (optional metadata).

This does not affect application; it can be used by tooling or higher-level systems to label/group tracks.

Returns

string

Set Signature

set target(val): void

Defined in: libs/scene/src/animation/animationtrack.ts:75

Parameters

val

string

Returns

void

---

jointIndex

Get Signature

get jointIndex(): number

Defined in: libs/scene/src/animation/animationtrack.ts:81

Joint index if this track controls a joint, otherwise -1

Returns

number

Set Signature

set jointIndex(index): void

Defined in: libs/scene/src/animation/animationtrack.ts:84

Parameters

index

number

Returns

void

Methods

clone()

abstract clone(): this

Defined in: libs/scene/src/animation/animationtrack.ts:90

Clone this animation track

Returns

this

---

reset()

reset(_target): void

Defined in: libs/scene/src/animation/animationtrack.ts:98

Reset the track to its initial state for the given target.

Intended to stop playback and rewind the target to the first frame or default state.

Parameters

_target

object

The animated object to reset.

Returns

void

---

calculateState()

abstract calculateState(target, currentTime): StateType

Defined in: libs/scene/src/animation/animationtrack.ts:109

Compute the animation state at the specified time.

Implementations should be pure with respect to inputs: given the same target and currentTime, return the same StateType.

Parameters

target

object

The animated object (used to resolve current baseline if needed).

currentTime

number

Time cursor in seconds within the track's timeline.

Returns

StateType

The computed state at currentTime.

---

applyState()

abstract applyState(target, state): unknown

Defined in: libs/scene/src/animation/animationtrack.ts:116

Apply a previously computed animation state to the target.

Parameters

target

object

The animated object to modify.

state

StateType

The state to apply.

Returns

unknown

---

mixState()

abstract mixState(a, b, t): StateType

Defined in: libs/scene/src/animation/animationtrack.ts:125

Blend two states into a new state using a weight.

Parameters

a

StateType

First state.

b

StateType

Second state.

t

number

Blend weight in [0, 1], where 0 yields a and 1 yields b.

Returns

StateType

The blended state.

---

getBlendId()

abstract getBlendId(): unknown

Defined in: libs/scene/src/animation/animationtrack.ts:134

Get the blend identifier for this track.

Tracks with the same blend ID are considered compatible for blending on the same target channel/property.

Returns

unknown

An identifier used to group compatible tracks for blending.

---

getDuration()

abstract getDuration(): number

Defined in: libs/scene/src/animation/animationtrack.ts:142

Get the intrinsic duration of this track in seconds.

Used by clips to determine overall clip duration and looping behavior.

Returns

number

Track duration (seconds).