<!-- This file is generated automatically. Do not edit it directly. -->
# three-mesh-bvh/webgpu

## TSL Functions

### closestPointToTriangle

```js
closestPointToTriangle: FunctionNode
```

WGSL function node that finds the closest point on a triangle to `p` and returns the barycoord.

### intersectRayTriangle

```js
intersectRayTriangle: FunctionNode
```

WGSL function node that tests a ray against a single triangle and returns an
[rayIntersectionResultStruct](rayIntersectionResultStruct) result. Useful when writing a custom `intersectRangeFn`
for [BVHComputeData#getShapecastFn](BVHComputeData#getShapecastFn).

### ndcToCameraRay

```js
ndcToCameraRay: FunctionNode
```

WGSL function node that builds a camera ray (origin + far-plane direction) from an NDC
coordinate and an inverse model-view-projection matrix. Works for both perspective and
orthographic projections. The returned direction is not normalized and extends to the
camera far plane.

## TSL Structs

### rayStruct

```js
rayStruct: StructTypeNode
```

WGSL struct node representing a ray with an origin and direction.
Used as the input to BVH traversal and intersection functions.

### rayIntersectionResultStruct

```js
rayIntersectionResultStruct: StructTypeNode
```

WGSL struct node describing a ray–triangle intersection result, including barycentric
coordinates, world-space normal, hit distance, face side, triangle indices, and the
object index within the TLAS.

### pointQueryResultStruct

```js
pointQueryResultStruct: StructTypeNode
```

WGSL struct node describing a closest-point query result, including the world-space
closest point, squared distance, barycentric coordinates, face normal, side, triangle
indices, and the object index within the TLAS.

Barycoord convention matches [rayIntersectionResultStruct](rayIntersectionResultStruct): `(bary_a, bary_b, bary_c)`
where each component is the weight for the corresponding vertex in `faceIndices.xyz`.

## BVHComputeData

Packs one or more scene objects into GPU-accessible BVH buffers (TLAS + BLAS) for use
in WebGPU compute shaders via the Three.js TSL node system. After construction, call
[BVHComputeData#update](BVHComputeData#update) to populate the storage buffers, then reference
`this.storage` and `this.fns` in your compute shader nodes.

> [!NOTE]
> This API is unstable and subject to change in future releases.

> [!NOTE]
> This class requires three.js r185 or higher.

### .constructor

```js
constructor(
	objects: Object3D | BufferGeometry | GeometryBVH | Array,
	{
		// WGSL type map for the interleaved per-vertex attribute
		// buffer. Keys are geometry attribute names; values are WGSL
		// type strings (e.g. `'vec3f'`, `'vec4f'`).
		attributes = { position: 'vec4f' }: Record<string, string>,

		// When true, a [MeshBVH](MeshBVH) is automatically built for any
		// object that does not already have `geometry.boundsTree` set.
		autogenerateBvh = true: boolean,
	}
)
```

### .getRootObject

```js
getRootObject(): Object3D
```

Returns the representative root object for the scene to be constructed.


### .getShapecastFn

```js
getShapecastFn(
	{
		// Function name. Defaults to a random identifier.
		name?: string,

		// TSL struct or definition describing the query shape.
		shapeStruct: StructTypeNode,

		// TSL struct for the accumulated result, or null.
		resultStruct?: StructTypeNode | null,

		// function node controlling left/right child traversal order.
		boundsOrderFn?: function | null,

		// function node testing the shape against a BVH node's bounds.
		intersectsBoundsFn: function,

		// function node testing the shape against a leaf triangle
		// range.
		intersectRangeFn: function,

		// function node that transforms the shape into object local
		// space.
		transformShapeFn?: function | null,

		// function node that transforms a hit result back to world
		// space.
		transformResultFn?: function | null,

		// function node called after each BLAS traversal to reset any
		// per-object state set by `transformShapeFn`.
		resetShapeFn?: function | null,
	}
): function
```

Builds a WGSL shapecast function that traverses the TLAS and per-cluster BLAS in a single
merged stack/loop for a custom shape type. The returned function signature is:
`fn name( shape: ShapeStruct[, result: ptr<function, ResultStruct>] ) -> bool`


### .update

```js
update(): void
```

Rebuilds all GPU storage buffers from the current scene state. Must be called at least
once before using `this.storage` or `this.fns` in a shader, and again whenever the
scene topology changes (objects added/removed, geometry modified).


### .updateTransforms

```js
updateTransforms(): void
```

Refits the clustered BVH and rewrites every entry in the transform buffer from the objects'
current world matrices. Call this when object transforms or visibility change but the scene
topology does not. The transform slots are derived from the clustered BVH's primitive buffer,
so they match those written by [BVHComputeData#update](BVHComputeData#update).


### .dispose

```js
dispose(): void
```

Releases GPU resources held by this instance.