WebGPU fallback texture load failure

Bugs
,
1

The code to reproduce the bug is very simple.

Here’s a reproduction: Babylon.js Playground (babylonjs.com)

new BABYLON.Texture("asdf", scene, {
    format: BABYLON.Constants.TEXTUREFORMAT_RGB,
    onError: (message, exception) => {
        console.log(message, exception);
    }
});

In fact, it’s a bit ambiguous to even call it a bug.

Let me explain.

  1. attempting to load a texture from the invalid texture url “asdf”.
  2. the texture load fails and attempts to load a fallback texture.
  3. TEXTUREFORMAT_RGB is a format not supported by WebGPU, try to load fallback texture using it.
  4. fallback texture loading fails.

You might think that this is not a bug and that this is the intended behavior. However, what actually happened is different from the logged text.

see:
image

I think it should force the texture format to be compatible when loading fallback textures, or at least log that the fallback texture is not being loaded.

2

@sebavan - we should probably provide RGBA-fallback texture?

3

I’m not sure…

It could be problematic if the user asks for RGB and gets a RGBA silently in return. I don’t think the fallback mechanism should alter the format of the texture. RGB is simply not supported in WebGPU, so the user should explicitely deal with it.

5

Sorry, just noticed the explicit request for the texture format. Got it - makes sense

6

Then I think the fallback texture shouldn’t be attempted either, as it is a guaranteed failure to load the fallback texture when the texture format is RGB.

We need a mechanism to handle cases where the fallback texture fails to load, or to pre-check if the fallback texture is in a condition that would cause it to fail to load.