Texture Error loading in WebGPU loader gltf compressed example

[Thakisis]

Description

Work fine in firefox but throw error in chrome/edge

Reproduction steps

Code

// code goes here

Live example

• jsfiddle-latest-release
• jsfiddle-dev

Screenshots

Version

163

Device

Desktop

Browser

Chrome, Edge

OS

Windows

[RenaudRohlinger]

Can't reproduce on MacOS. Could this be related to #28021?

[Mugen87]

The OP uses r163 (see URL) and #28021 is only on the dev branch.

I can't reproduce on macOS as well.

[Mugen87]

The numeric value 33776 corresponds to ext.COMPRESSED_RGB_S3TC_DXT1_EXT so the texture is using RGB_S3TC_DXT1_Format.

@Thakisis Can you make a test with Chrome Canary and see if the issue persists?

[Thakisis]

sure i will try in other two computers and tell you if that error persist

[Thakisis]

Tried different computers. 2 laptop and other desktop and same problem.

[GitHubDragonFly]

If it helps with this issue, I use a Windows 10 laptop and this example works in both Chrome and Edge.

[Mugen87]

This issue is actually a duplicate of #26124.

On macOS (at least on my system) KTX2Loader produces an ETC2 texture (RGB_ETC2_Format) which is properly supported in WebGPURenderer. However, on Windows I can confirm the loader produces RGB_S3TC_DXT1_Format which is an unsupported format in WebGPU. It has to be a RGBA format meaning RGBA_S3TC_DXT1_Format.

@donmccurdy Can we tell KTX2Loader somehow not to target RGB_S3TC_DXT1_Format in context of WebGPU? Currently WebGPURenderer supports RGBA_S3TC_DXT1_Format, RGBA_S3TC_DXT3_Format and RGBA_S3TC_DXT5_Format all with optional SRGBColorSpace. Relevant code section:

three.js/examples/jsm/renderers/webgpu/utils/WebGPUTextureUtils.js

Lines 827 to 837 in 9b5d697

	case RGBA_S3TC_DXT1_Format:
	formatGPU = ( colorSpace === SRGBColorSpace ) ? GPUTextureFormat.BC1RGBAUnormSRGB : GPUTextureFormat.BC1RGBAUnorm;
	break;
	case RGBA_S3TC_DXT3_Format:
	formatGPU = ( colorSpace === SRGBColorSpace ) ? GPUTextureFormat.BC2RGBAUnormSRGB : GPUTextureFormat.BC2RGBAUnorm;
	break;
	case RGBA_S3TC_DXT5_Format:
	formatGPU = ( colorSpace === SRGBColorSpace ) ? GPUTextureFormat.BC3RGBAUnormSRGB : GPUTextureFormat.BC3RGBAUnorm;
	break;

[Mugen87]

Closing in favor of #26124.

[donmccurdy]

Can we tell KTX2Loader somehow not to target RGB_S3TC_DXT1_Format in context of WebGPU?

I think we could do that unconditionally for both WebGL and WebGPU. BC1 has a 1-bit alpha channel, which probably is there regardless of whether we specify RGB or RGBA.