WebGPURenderer: BatchMesh support for Instanced rendering with sorting, frustum culling

[RenaudRohlinger]

Related issue: #28462

Description

This PR aligns the BatchNode with the new BatchMesh API.

I had to implement several features to achieve this:

• Update BatchNode with the new BatchMesh API.
• Support uint/int textures for DataTexture in the GLSLNodeBuilder.
• Introduce extensions definition in the GLSLNodeBuilder (currently only for vertex).
• Fix forward the type if it's a uint/int data texture in the TextureNode.
• Add a 4th argument to TextureNode to override the nodeType.
• Add a new drawIndex in IndexNode (gl_drawID in WebGL).

This contribution is funded by Utsubo

[sunag]

@RenaudRohlinger I push a commit releated to sort in webgpu, could confirm if your issue is related with this? Seems that some objects are being ignored in webgpu but I haven't checked the reason yet.

[RenaudRohlinger]

Thanks @sunag! Unfortunately we cannot use the instanceIndex that's the whole issue of the current implement of the BatchMesh fallback. It needs to be related to the current draw index instead.

[RenaudRohlinger]

Otherwise for the WebGPURenderer instead of running this every frame:

const uniforms = properties.get( material ).currentProgram.getUniforms();
for ( let i = 0; i < drawCount; i ++ ) {

	uniforms.setValue( _gl, '_gl_DrawID', i );
	renderer.render( starts[ i ] / bytesPerElement, counts[ i ] );

}

Could there be any alternative like storing the drawId into an attribute or a DataTexture for example? @gkjohnson

I think it might be necessary as I also worried about the renderBundle case that will not be able to run this code (except maybe with indirectDrawCall in WebGPU). I worry the previous implementation of BatchMesh was a more appropriate version for WebGPU.

Edit: Found out that Sunag solved the issue as it seems like with WebGPU we can specify the firstInstanceID in the draw command (last argument of drawIndexed) which makes the fallback super clean.

[sunag]

I fixed in webgpu backend:

[RenaudRohlinger]

Wow with WebGPU you can manually specify the first Instance ID in drawIndexed? This is actually super cool!! Amazing!

[RenaudRohlinger]

@sunag Tell me when you're done with your review, I will clean up the code and merge the PR if it's ok with you. 😊

PS: By the way I don't think it would make sense to take the time to support the WebGL fallback only for firefox. By the time the WebGPURenderer become more popular firefox will probably already support WebGPU.

[sunag]

PS: By the way I don't think it would make sense to take the time to support the WebGL fallback only for firefox. By the time the WebGPURenderer become more popular firefox will probably already support WebGPU.

I agree, I thought the same thing. Maybe we could have a warnOnce for this case?

Great work, I think that was all.