Class CubicBezierCurve

A Curve along which a 3D position can be animated.

A CubicBezierCurve is defined by four control points.

Hierarchy (View Summary)

Curve
- CubicBezierCurve

Index

Constructors

constructor

new CubicBezierCurve(
cfg?: { t?: number; v0?: Vec3; v1?: Vec3; v2?: Vec3; v3?: Vec3 },
): CubicBezierCurve
Parameters
- cfg: { t?: number; v0?: Vec3; v1?: Vec3; v2?: Vec3; v3?: Vec3 } = {}
  Configs
  - Optionalt?: number
    Current position on this CubicBezierCurve, in range between 0..1.
  - Optionalv0?: Vec3
    The starting point.
  - Optionalv1?: Vec3
    The first control point.
  - Optionalv2?: Vec3
    The second control point.
  - Optionalv3?: Vec3
    The ending point.
Returns CubicBezierCurve
Overrides Curve.constructor
- Defined in packages/sdk/src/base/math/curves/CubicBezierCurve.ts:24

Properties

`Protected` `Optional`__arcLengthDivisions

__arcLengthDivisions?: number

`Protected`_t

_t: number = 0

`Protected`_v0

_v0: Vec3 = ...

`Protected`_v1

_v1: Vec3 = ...

`Protected`_v2

_v2: Vec3 = ...

`Protected`_v3

_v3: Vec3 = ...

`Protected` `Optional`cacheArcLengths

cacheArcLengths?: number[]

`Protected` `Optional`needsUpdate

needsUpdate?: boolean

Accessors

length

get length(): number
Approximate arc length of the curve.

Computed from cached sampled lengths.

Returns number
Inherited from Curve.length
- Defined in packages/sdk/src/base/math/curves/Curve.ts:51

point

get point(): Vec3
Point on the curve at the current t.

Returns Vec3
- Defined in packages/sdk/src/base/math/curves/CubicBezierCurve.ts:85

t

get t(): number
Returns number
Inherited from Curve.t
- Defined in packages/sdk/src/base/math/curves/Curve.ts:35
set t(value: number): void
Current curve parameter.

Clamped to the range [0..1].
Parameters
- value: number
Returns void
Inherited from Curve.t
- Defined in packages/sdk/src/base/math/curves/Curve.ts:30

tangent

get tangent(): Vec3
Normalized tangent at the current t.

Returns Vec3
Inherited from Curve.tangent
- Defined in packages/sdk/src/base/math/curves/Curve.ts:42

v0

get v0(): Vec3
Returns Vec3
- Defined in packages/sdk/src/base/math/curves/CubicBezierCurve.ts:42
set v0(value: Vec3): void
Starting point.
Parameters
- value: Vec3
Returns void
- Defined in packages/sdk/src/base/math/curves/CubicBezierCurve.ts:37

v1

get v1(): Vec3
Returns Vec3
- Defined in packages/sdk/src/base/math/curves/CubicBezierCurve.ts:54
set v1(value: Vec3): void
First control point.
Parameters
- value: Vec3
Returns void
- Defined in packages/sdk/src/base/math/curves/CubicBezierCurve.ts:49

v2

get v2(): Vec3
Returns Vec3
- Defined in packages/sdk/src/base/math/curves/CubicBezierCurve.ts:66
set v2(value: Vec3): void
Second control point.
Parameters
- value: Vec3
Returns void
- Defined in packages/sdk/src/base/math/curves/CubicBezierCurve.ts:61

v3

get v3(): Vec3
Returns Vec3
- Defined in packages/sdk/src/base/math/curves/CubicBezierCurve.ts:78
set v3(value: Vec3): void
End point.
Parameters
- value: Vec3
Returns void
- Defined in packages/sdk/src/base/math/curves/CubicBezierCurve.ts:73

Methods

`Protected`_getLengths

_getLengths(divisions?: number): number[]
Returns cumulative sampled arc lengths for the curve.

The returned array starts at 0 and ends at the total sampled length. Results are cached until invalidated.
Parameters
- Optionaldivisions: number
  Number of sampling divisions used to approximate arc length
Returns number[]
Cumulative arc lengths
Inherited from Curve._getLengths
- Defined in packages/sdk/src/base/math/curves/Curve.ts:127

`Protected`_updateArcLengths

_updateArcLengths(): void
Invalidates cached arc-length data and rebuilds it.

Returns void
Inherited from Curve._updateArcLengths
- Defined in packages/sdk/src/base/math/curves/Curve.ts:163

getJSON

getJSON(): { t: number; v0: Vec3; v1: Vec3; v2: Vec3; v3: Vec3 }
Returns { t: number; v0: Vec3; v1: Vec3; v2: Vec3; v3: Vec3 }
- Defined in packages/sdk/src/base/math/curves/CubicBezierCurve.ts:105

getPoint

getPoint(t: number): Vec3
Returns point on this CubicBezierCurve at the given position.
Parameters
- t: number
Returns Vec3
Overrides Curve.getPoint
- Defined in packages/sdk/src/base/math/curves/CubicBezierCurve.ts:92

getPointAt

getPointAt(u: number): Vec3
Returns a point using normalized arc-length parameterization.

Unlike getPoint, u maps to distance along the curve rather than directly to the curve parameter.
Parameters
- u: number
  Normalized distance along the curve in the range [0..1]
Returns Vec3
Point on the curve
Inherited from Curve.getPointAt
- Defined in packages/sdk/src/base/math/curves/Curve.ts:97

getPoints

getPoints(divisions?: number): Vec3[]
Samples points at evenly spaced parameter intervals.
Parameters
- divisions: number = 5
  Number of intervals to divide [0..1] into
Returns Vec3[]
Sampled points, including both endpoints
Inherited from Curve.getPoints
- Defined in packages/sdk/src/base/math/curves/Curve.ts:108

getTangent

getTangent(t?: number): Vec3
Returns the normalized tangent at parameter t.

Uses a small finite difference around t.
Parameters
- Optionalt: number
  Curve parameter in the range [0..1]. Defaults to the current t.
Returns Vec3
Normalized tangent vector
Inherited from Curve.getTangent
- Defined in packages/sdk/src/base/math/curves/Curve.ts:64

getUToTMapping

getUToTMapping(u: number, distance?: number): number
Maps normalized arc-length parameter u to curve parameter t.

This is useful when you want points spaced by distance along the curve instead of by raw parameter value.
Parameters
- u: number
  Normalized distance along the curve in the range [0..1]
- Optionaldistance: number
  Absolute distance along the curve. When provided, overrides u.
Returns number
Curve parameter in the range [0..1]
Inherited from Curve.getUToTMapping
- Defined in packages/sdk/src/base/math/curves/Curve.ts:178

Class CubicBezierCurve

Hierarchy (View Summary)

Index

Constructors

Properties

Accessors

Methods

Constructors

constructor

Parameters

Optionalt?: number

Optionalv0?: Vec3

Optionalv1?: Vec3

Optionalv2?: Vec3

Optionalv3?: Vec3

Returns CubicBezierCurve

Properties

Protected Optional__arcLengthDivisions

Protected_t

Protected_v0

Protected_v1

Protected_v2

Protected_v3

Protected OptionalcacheArcLengths

Protected OptionalneedsUpdate

Accessors

length

Returns number

point

Returns Vec3

t

Returns number

Parameters

Returns void

tangent

Returns Vec3

v0

Returns Vec3

Parameters

Returns void

v1

Returns Vec3

Parameters

Returns void

v2

Returns Vec3

Parameters

Returns void

v3

Returns Vec3

Parameters

Returns void

Methods

Protected_getLengths

Parameters

Returns number[]

Protected_updateArcLengths

Returns void

getJSON

Returns { t: number; v0: Vec3; v1: Vec3; v2: Vec3; v3: Vec3 }

getPoint

Parameters

Returns Vec3

getPointAt

Parameters

Returns Vec3

getPoints

Parameters

Returns Vec3[]

getTangent

Parameters

Returns Vec3

getUToTMapping

Parameters

Returns number

Settings

On This Page

`Optional`t?: number

`Optional`v0?: Vec3

`Optional`v1?: Vec3

`Optional`v2?: Vec3

`Optional`v3?: Vec3

`Protected` `Optional`__arcLengthDivisions

`Protected`_t

`Protected`_v0

`Protected`_v1

`Protected`_v2

`Protected`_v3

`Protected` `Optional`cacheArcLengths

`Protected` `Optional`needsUpdate

`Protected`_getLengths

`Protected`_updateArcLengths