geometry#setWasmAttributes¶

Summary¶

geometry#setWasmAttributes() installs or replaces several borrowed WebAssembly vertex and index sources as one operation. It refreshes the supplied sources immediately, validates their active ranges, and schedules their data for a later upload().

Syntax¶

Geometry.setWasmAttributes(sources: GeometryWasmSources, options?: GeometryWasmAttributeSetOptions): void

Parameters¶

type GeometryWasmSources = {
    positions?: WasmMemoryView<Float32Array> | null;
    normals?: WasmMemoryView<Float32Array> | null;
    tangents?: WasmMemoryView<Float32Array> | null;
    colors?: WasmMemoryView<Float32Array> | null;
    uvs?: WasmMemoryView<Float32Array> | null;
    uvs1?: WasmMemoryView<Float32Array> | null;
    joints?: WasmMemoryView<Uint16Array> | null;
    weights?: WasmMemoryView<Float32Array> | null;
    joints1?: WasmMemoryView<Uint16Array> | null;
    weights1?: WasmMemoryView<Float32Array> | null;
    indices?: WasmMemoryView<Uint32Array> | null;
};

type GeometryWasmAttributeSetOptions = {
    vertexCount?: number;
    indexCount?: number;
    capacity?: number;
    vertexCapacity?: number;
    indexCapacity?: number;
    keepCPUData?: boolean;
    recomputeBounds?: boolean;
};

An omitted source property preserves that channel. An explicit null detaches it and removes its WasmGPU-managed GPU copy. vertexCapacity and indexCapacity override the shared capacity hint for their respective channel families; capacity hints do not change the active counts.

Data layout and validation¶

Vertex channels contain one tightly packed record per vertex:

Channel	View element type	Elements per vertex
`positions`, `normals`	`f32`	3
`tangents`, `colors`	`f32`	4
`uvs`, `uvs1`	`f32`	2
`joints`, `joints1`	`u16`	4
`weights`, `weights1`	`f32`	4
`indices`	`u32`	1 per index

When vertexCount is omitted and positions are attached, their complete records determine the active vertex count. Otherwise the current vertex count is retained. When indexCount is omitted, the index view length determines it. Every attached channel must cover its active count. Joint and weight channels are supplied as matching pairs; the second pair is optional.

A CPU array and WebAssembly view cannot both supply the same channel. WebAssembly positions are not supported for geometry with morph targets.

Ownership, refresh, and upload¶

The geometry borrows each WasmMemoryView and never frees its WebAssembly allocation. keepCPUData optionally retains copies of active records for CPU access. With recomputeBounds: true, non-explicit bounds are recomputed from active positions; explicitly supplied bounds remain unchanged.

After the producer writes new data or changes exported pointer/length metadata, call refreshFromWasm() before relying on retained CPU data or bounds. Refreshing does not transfer data to WebGPU. upload(device) copies dirty active ranges into buffers owned by the geometry.

Example¶

geometry.setWasmAttributes(
    {
        positions: positionsView,
        normals: normalsView,
        indices: indicesView
    },
    {
        vertexCount,
        indexCount,
        vertexCapacity: maximumVertices,
        indexCapacity: maximumIndices,
        keepCPUData: true,
        recomputeBounds: true
    }
);

// After the producer changes the active records:
geometry.refreshFromWasm({ vertexCount: nextVertexCount, indexCount: nextIndexCount, recomputeBounds: true });
geometry.upload(wgpu.gpu.device);