WebGPU: Support more texture formats transcoded from KTX2

[hybridherbst]

Description

Seems this example: https://threejs.org/examples/?q=compressed#webgpu_loader_gltf_compressed
produces an error message: WebGPURenderer: Unsupported texture format. 33776

Reproduction steps

1. Go to https://threejs.org/examples/?q=compressed#webgpu_loader_gltf_compressed
2. Note nothing loads
3. Open console and see errors (an initial one and then every frame)

Code

Live example

https://threejs.org/examples/?q=compressed#webgpu_loader_gltf_compressed

Screenshots

No response

Version

latest + dev

Device

Desktop

Browser

Chrome

OS

Windows

[donmccurdy]

Related:

• WebGPUTextures: Basic support for ETC2. #25864
• KTX2Loader: Add WebGPU support. #25867

I believe our WebGPU implementation is limited to ETC2 at the moment, and DXT1 is not yet implemented. So this demo may or may not work, depending on the device accessing it.

[hybridherbst]

I see. Then maybe there should be a note regarding this in the header for now? For someone (e.g. me) looking at "how ready is WebGPU in three.js" a sample just logging exceptions isn't ideal I think.

[Mugen87]

S3TC is partly supported. The formats RGBA_S3TC_DXT1_Format, RGBA_S3TC_DXT3_Format and RGBA_S3TC_DXT5_Format with optional SRGBColorSpace should work.

[Mugen87]

WebGPURenderer: Unsupported texture format. 33776

33776 is RGB_S3TC_DXT1_Format. WebGPU does not support such a RGB format. It has to be RGBA_S3TC_DXT1_Format