`CustomWGSLPointsSource`

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Generates clone placements from your own WGSL — a procedural point distribution written as a GPU function, for shapes no built-in source covers (a helix, a gyroid, a formula-defined swarm).

Declarative element: <sk-custom-wgsl-points-source>

Global: available as sk.CustomWGSLPointsSource inside a scene <script>.

Remarks

This is the fully custom member of the points-source family (see ShaderFunctionPointsSource): a points-source defines the set of positions at which a sk-cloner places copies of its content, so it lives as a child of a <sk-cloner> and the cloner's other child is the template cloned at each point. Where the built-in procedural sources encode a fixed shape (sk-grid-points-source, sk-sphere-points-source, …), this one runs an author-supplied getPointAtIndex(index) on the GPU, so every point's local transform is whatever the WGSL computes — and, like the other procedural sources, the placements never touch the CPU, so even large counts stay cheap.

Key attributes. point-count is how many points to generate — the WGSL is evaluated once per index from 0 to point-count − 1. wgsl is the inline shader body; it must define fn getPointAtIndex(index: u32) -> PointData and set point.localMatrix (column 3 is the position, the +Y axis is the surface normal). src loads that WGSL from an external .wgsl file instead, taking precedence over inline wgsl (mirroring <script src>); on-load / on-error fire when a src fetch resolves or fails. Author parameters are supplied as <sk-wgsl-uniform> children and read in WGSL via the generated skUniform_<name>() accessors.

Related. For placements a GPU compute pass produces into a buffer rather than a per-index function, see sk-compute-buffer-points-source (which pairs with a sk-compute-node). For built-in procedural shapes see sk-grid-points-source, sk-sphere-points-source, and sk-platonic-sphere-points-source; for object/data-driven placements see sk-mesh-vertex-points-source, sk-mesh-surface-points-source, sk-buffer-points-source, and sk-cloner-points-source. Its host is always a sk-cloner.

Constructor

constructor(config?: { pointCount: number; wgsl?: string; src?: string })

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

Properties

Config Properties

Property	Type	Default	Description	Declared by
`pointCount`	`number`	`1`	Number of points to generate.	`CustomWGSLPointsSource`
`wgsl`	`string`	`""`	Inline WGSL shader code. Ignored while `src` is set.	`CustomWGSLPointsSource`
`src`	`string`	—	External WGSL source URL (the `src` attribute), or `null` if none.	`CustomWGSLPointsSource`

Other Properties

Property	Type	Default	Description	Declared by
`configuredPointCount`read-only	`number`	—	The configured point count, independent of the inert state.	`CustomWGSLPointsSource`
`hasEffectiveWGSL`read-only	`boolean`	—	Whether usable effective WGSL is available. `false` while a `src` is set	`CustomWGSLPointsSource`
`localMatrices`read-only	`Float32Array<ArrayBufferLike> \| null`	—	CPU-side local matrices.	`ShaderFunctionPointsSource`
`type`read-only	`PointsSourceType`	`"shader-function"`	The type of this points source.	`ShaderFunctionPointsSource`
`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: CustomWGSLPointsSourceConfig): void`	Declarative configuration API.	`CustomWGSLPointsSource`
`addUniform(name: string, value: number): WGSLUniform`	Imperative twin of authoring a `<sk-wgsl-uniform>` child.	`CustomWGSLPointsSource`
`addF32ArrayUniform(name: string, values: readonly number[]): WGSLF32ArrayUniform`	Imperative twin of authoring a `<sk-wgsl-f32-array-uniform>` child.	`CustomWGSLPointsSource`
`addVec2Uniform(name: string, x: number, y: number): WGSLVec2Uniform`	Imperative twin of authoring a `<sk-wgsl-vec2-uniform>` child.	`CustomWGSLPointsSource`
`addVec3Uniform(name: string, x: number, y: number, z: number): WGSLVec3Uniform`	Imperative twin of authoring a `<sk-wgsl-vec3-uniform>` child.	`CustomWGSLPointsSource`
`addVec4Uniform(name: string, x: number, y: number, z: number, w: number): WGSLVec4Uniform`	Imperative twin of authoring a `<sk-wgsl-vec4-uniform>` child.	`CustomWGSLPointsSource`
`addColorUniform(name: string, color: ColorInput): WGSLColorUniform`	Imperative twin of authoring a `<sk-wgsl-color-uniform>` child.	`CustomWGSLPointsSource`
`getBoundsInSpace(fullTransform: Float32Array): { minX: number; maxX: number; minY: number; maxY: number; minZ: number; maxZ: number; } \| null`	Computes the AABB in target space by transforming local bounds corners.	`ShaderFunctionPointsSource`
`setWorldReferenceNode(node: WorldReferenceNode \| null): void`	Sets the reference node whose world matrix should be used for transforms.	`ShaderFunctionPointsSource`
`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 helixSource = new CustomWGSLPointsSource({
    pointCount: 200,
    wgsl: `
        fn getPointAtIndex(index: u32) -> PointData {
            var point: PointData;
            let t = f32(index) / skUniform_count();
            let angle = t * 6.283 * 4.0;
            let pos = vec3<f32>(cos(angle) * skUniform_radius(), t * skUniform_pitch(), sin(angle) * skUniform_radius());
            // Identity basis → +Y surface normal; position in column 3.
            point.localMatrix = mat4x4<f32>(
                vec4<f32>(1.0, 0.0, 0.0, 0.0),
                vec4<f32>(0.0, 1.0, 0.0, 0.0),
                vec4<f32>(0.0, 0.0, 1.0, 0.0),
                vec4<f32>(pos, 1.0)
            );
            return point;
        }
    `,
});
// Parameters are <sk-wgsl-uniform> children (count/radius/pitch).

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