`CustomWGSLPointConstraint`

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Displaces every point of a host with a GPU kernel you write inline in WGSL — the escape hatch for any per-point deformation the built-in point-constraints don't cover.

Declarative element: <sk-custom-wgsl-point-constraint>

Not on the sk.* global — construct via the declarative element or a module import.

Remarks

This is the fully-programmable member of the PointConstraint family: like every point-constraint it runs a GPU kernel over all of a host's points at once (a mesh, a spline, or a sk-cloner). What is unique here is that you supply the kernel body: the engine owns the scaffold (world-space sampling, the field-weight range, per-target buffer I/O) and calls your computeDisplacement() for each point, plus an optional computeGradient() when the result should also recompute normals.

Key attributes. wgsl holds the kernel source — at minimum a computeDisplacement(worldXZ) function returning a world-space offset. Its tunable parameters come from sk-wgsl-uniform elements attached to it, read inside the kernel through generated skUniform_<name>() accessors, so each is independently animatable. affects-normals turns on the computeGradient() path so shading and cloner orientation follow the deformed surface. max-displacement reports the kernel's worst-case travel so bounds stay correct. It is the per-point cousin of sk-compute-node, which produces whole output buffers that compute-buffer sources consume by reference.

Related. For a ready-made wave there is sk-ocean-displacement-point-constraint; for field-weighted translate/scale/rotate there is sk-simple-point-constraint. Its single-node CPU analogue is sk-field-constraint.

Constructor

constructor(config?: { wgsl?: string; src?: string; affectsNormals?: boolean; maxDisplacement?: number; timeDependent?: boolean; show?: boolean; fieldWeightRange?: readonly [number, number] })

Inherited from: PointConstraint, SkenraAnimatable — see those pages for inherited members.

Properties

Config Properties

Property	Type	Default	Description	Declared by
`wgsl`	`string`	`""`	Inline WGSL shader code. Ignored while `src` is set.	`CustomWGSLPointConstraint`
`src`	`string`	—	External WGSL source URL (the `src` attribute), or `null` if none.	`CustomWGSLPointConstraint`
`affectsNormals`read-only	`boolean`	`false`	Whether the kernel recomputes normals / cloner orientation from the	`CustomWGSLPointConstraint`
`maxDisplacement`	`number`	`0`	Analytic upper-bound displacement magnitude (world units), used to	`CustomWGSLPointConstraint`
`timeDependent`	`boolean`	`false`	Whether the kernel must be re-dispatched every frame.	`CustomWGSLPointConstraint`
`show`	`boolean`	`true`	Whether the constraint is active.	`CustomWGSLPointConstraint`
`fieldWeightRange`animatable	`readonly [number, number]`	—	The `[lo, hi]` range the normalized field weight maps onto.	`PointConstraint`

Other Properties

Property	Type	Default	Description	Declared by
`hasEffectiveWGSL`read-only	`boolean`	—	Whether usable effective WGSL is available. `false` while a `src` is set	`CustomWGSLPointConstraint`
`target`read-only	`ConstrainablePointsHost \| null`	—	The target host this modifier applies to, or `null` before	`PointConstraint`
`field`read-only	`Field \| null`	—	The field used by this point constraint, if any.	`PointConstraint`
`scene`read-only	`any`	—	Gets the Scene this animatable belongs to, if any.	`SkenraAnimatable`
`animations`read-only	`SkenraAnimation[]`	—	Public getter for the animations affecting this target.	`SkenraAnimatable`

Methods

Method	Description	Declared by
`configure(config: CustomWGSLPointConstraintConfig): void`	Declarative configuration API — sets the WGSL + params after the	`CustomWGSLPointConstraint`
`addUniform(name: string, value: number): WGSLUniform`	Imperative twin of authoring a `<sk-wgsl-uniform>` child.	`CustomWGSLPointConstraint`
`addF32ArrayUniform(name: string, values: readonly number[]): WGSLF32ArrayUniform`	Imperative twin of authoring a `<sk-wgsl-f32-array-uniform>` child.	`CustomWGSLPointConstraint`
`addVec2Uniform(name: string, x: number, y: number): WGSLVec2Uniform`	Imperative twin of authoring a `<sk-wgsl-vec2-uniform>` child.	`CustomWGSLPointConstraint`
`addVec3Uniform(name: string, x: number, y: number, z: number): WGSLVec3Uniform`	Imperative twin of authoring a `<sk-wgsl-vec3-uniform>` child.	`CustomWGSLPointConstraint`
`addVec4Uniform(name: string, x: number, y: number, z: number, w: number): WGSLVec4Uniform`	Imperative twin of authoring a `<sk-wgsl-vec4-uniform>` child.	`CustomWGSLPointConstraint`
`addColorUniform(name: string, color: ColorInput): WGSLColorUniform`	Imperative twin of authoring a `<sk-wgsl-color-uniform>` child.	`CustomWGSLPointConstraint`
`animate(firstArg: TypedKeyframe<this>[] \| TypedPropertyIndexedKeyframes<this> \| Record<string, any> \| globalThis.Keyframe[] \| globalThis.PropertyIndexedKeyframes \| null, secondArg?: number \| KeyframeAnimationOptions \| globalThis.KeyframeAnimationOptions): SkenraAnimation & Animation`	Creates a new SkenraAnimation for this target per Web Animations API.	`SkenraAnimatable`
`removeAnimation(animation: SkenraAnimation): boolean`	Removes a specific animation from this object.	`SkenraAnimatable`
`constrain(type: K, config: ConstraintConfigMap[K]): ConstraintReturnMap[K]`	Creates a constraint on this Animatable using a fluent API.	`SkenraAnimatable`

Example

const sine = new CustomWGSLPointConstraint({
    wgsl: SINE_WAVE_WGSL,           // reads skUniform_amplitude() etc.
    maxDisplacement: 50,
    affectsNormals: true,
});
plane.addPointConstraint(sine);

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