WebGPURenderer: Unable to remove map from SpotLight.

[Mugen87]

Description

Removing a map assigned to a spot light triggers a runtime error:

three.webgpu.js:26114 Uncaught TypeError: Invalid value used as weak map key
at WeakMap.set ()
at Textures.get (three.webgpu.js:26114:14)
at Textures.updateTexture (three.webgpu.js:28797:28)
at Bindings._update (three.webgpu.js:27704:20)
at Bindings._updateBindings (three.webgpu.js:27606:9)
at Bindings.updateForRender (three.webgpu.js:27593:8)
at WebGPURenderer._renderObjectDirect (three.webgpu.js:52189:19)
at WebGPURenderer.renderObject (three.webgpu.js:52128:9)
at WebGPURenderer._renderObjects (three.webgpu.js:52043:9)
at WebGPURenderer._renderScene (three.webgpu.js:50726:64)

I believe this happens since the renderer does not detect a new render object with a new node builder state is required in that case.

Reproduction steps

1. Open https://threejs.org/examples/webgpu_lights_spotlight
2. Use the GUI to change the map to null.
3. Observe runtime error in browser console.

Code

see live example

Live example

https://threejs.org/examples/webgpu_lights_spotlight

Expected behavior visible in: https://threejs.org/examples/webgl_lights_spotlight

Screenshots

No response

Version

r175dev

Device

No response

Browser

No response

OS

No response

[Spiri0]

I can't tell if this is the same cause as what I'm doing.
I created my own light source, and in order to update the shadow map, I have to detach it from the fragment shader, since you can't use a texture for both read and write at the same time.
In wgsl, however, the uniform input of a texture cannot be null. Therefore, I have an emptyPlaceHolder texture that first takes up the place in the shader texture uniform. Then my shadow map is free for the render target and can be updated. After that, I swap the textures again. This works well, and at no point do I have a null in the wgsl shader.
The placeholder texture doesn't even need pixels. What matters is the texture metadata, which is what's important for the shader.
wgsl doesn't like null in its inputs

[Mugen87]

The issue is more about the internal caching system which does not recognize the need for a refresh. Hence, outdated bindings are used which result in the mentioned runtime error.