Class SplineCurve

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

A SplineCurve is defined by three or more control points.
You can sample a point and a tangent vector on a SplineCurve for any given value of t in the range [0..1].
When you set t on a SplineCurve, its point and tangent update accordingly.

Hierarchy (View Summary)

Curve
- SplineCurve

Index

Constructors

constructor

new SplineCurve(cfg?: { points?: Vec3[]; t?: number }): SplineCurve
Parameters
- cfg: { points?: Vec3[]; t?: number } = {}
  Configs
  - Optionalpoints?: Vec3[]
    Control points on this SplineCurve.
  - Optionalt?: number
    Current position on this SplineCurve, in range between 0..1.
Returns SplineCurve
Overrides Curve.constructor
- Defined in packages/sdk/src/base/math/curves/SplineCurve.ts:21

Properties

`Protected` `Optional`__arcLengthDivisions

__arcLengthDivisions?: number

`Protected`_points

_points: Vec3[] = []

`Protected`_t

_t: number = 0

`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
Gets the point on this SplineCurve at position t.

Returns Vec3
- Defined in packages/sdk/src/base/math/curves/SplineCurve.ts:49

points

get points(): Vec3[]
Gets the control points on this SplineCurve.

Default value is [].

Returns Vec3[]
- Defined in packages/sdk/src/base/math/curves/SplineCurve.ts:42
set points(value: Vec3[]): void
Sets the control points on this SplineCurve.

Default value is [].
Parameters
- value: Vec3[]
Returns void
- Defined in packages/sdk/src/base/math/curves/SplineCurve.ts:32

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

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(): { points: Vec3[]; t: number }
Returns { points: Vec3[]; t: number }
- Defined in packages/sdk/src/base/math/curves/SplineCurve.ts:82

getPoint

getPoint(t: number): Vec3
Returns point on this SplineCurve at the given position.
Parameters
- t: number
Returns Vec3
Overrides Curve.getPoint
- Defined in packages/sdk/src/base/math/curves/SplineCurve.ts:56

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 SplineCurve

Hierarchy (View Summary)

Index

Constructors

Properties

Accessors

Methods

Constructors

constructor

Parameters

Optionalpoints?: Vec3[]

Optionalt?: number

Returns SplineCurve

Properties

Protected Optional__arcLengthDivisions

Protected_points

Protected_t

Protected OptionalcacheArcLengths

Protected OptionalneedsUpdate

Accessors

length

Returns number

point

Returns Vec3

points

Returns Vec3[]

Parameters

Returns void

t

Returns number

Parameters

Returns void

tangent

Returns Vec3

Methods

Protected_getLengths

Parameters

Returns number[]

Protected_updateArcLengths

Returns void

getJSON

Returns { points: Vec3[]; t: number }

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`points?: Vec3[]

`Optional`t?: number

`Protected` `Optional`__arcLengthDivisions

`Protected`_points

`Protected`_t

`Protected` `Optional`cacheArcLengths

`Protected` `Optional`needsUpdate

`Protected`_getLengths

`Protected`_updateArcLengths