NodeMaterialObserver: Force refresh for video textures.

[Mugen87]

Related issue: #31330 (comment)

Description

Using video textures in WebGPU seems more complicated than in WebGL since it is not possible to share an external texture. We have to recreate the bind group and the external texture for each render item. For material properties, we can enforce this in NodeMaterialObserver.

However, if video textures are used as spot light maps, there is no obvious way to enforce a refresh. Hence, I have removed the video texture from the webgpu_lights_projector demo. I think we can only properly support them on material level. And even then they are a bit problematic for performance in WebGPU since we can't share bindings in the same way like with normal textures.

I suggest to state in the documentation that video textures are not supported in SpotLight.map.

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	338.27 78.93	338.27 78.93	+0 B +0 B
WebGPU	558.54 154.59	558.57 154.59	+29 B +7 B
WebGPU Nodes	557.46 154.37	557.49 154.38	+29 B +7 B

🌳 Bundle size after tree-shaking

Minimal build including a renderer, camera, empty scene, and dependencies.

	Before	After	Diff
WebGL	469.62 113.66	469.62 113.66	+0 B +0 B
WebGPU	634.18 171.62	634.21 171.63	+29 B +9 B
WebGPU Nodes	589.31 160.95	589.34 160.96	+29 B +10 B

[sunag]

I'd like to analyze this in more detail. Currently we can take a uniform to an isolated group using uniform().setGroup() then we could share that group between materials using sharedUniformGroup(). But I didn't do the tests using VideoTexture.