NodeMaterialObserver: Force refresh when rendering velocity.

[Mugen87]

Related issue: -

Description

I've tried using TRAA in webgpu_postprocessing_fxaa and it turned out the AA did not work correctly. The problem is the update callbacks of VelocityNode don't get properly executed when render objects share the same node builder state. Hence, only one tetrahedron is properly anti-aliased, all others not because their motions vectors are not updated.

A refresh must be forced in the material observer when velocity rendering is active.

[Mugen87]

@sunag I'm not sure this is the best fix. Could VelocityNode be used without a MRT context?

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	336.36 78.34	336.36 78.34	+0 B +0 B
WebGPU	532.97 148.11	533.07 148.15	+103 B +40 B
WebGPU Nodes	532.43 148.01	532.54 148.05	+103 B +40 B

🌳 Bundle size after tree-shaking

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

	Before	After	Diff
WebGL	465.37 112.21	465.37 112.21	+0 B +0 B
WebGPU	604.58 164.08	604.68 164.12	+103 B +34 B
WebGPU Nodes	559.57 153.53	559.67 153.56	+103 B +33 B

[sunag]

@sunag I'm not sure this is the best fix. Could VelocityNode be used without a MRT context?

Let's continue like this for now, checking the MRT entry by the name velocity should be temporary, because in the future we may want to make a RenderTarget pack in order to save bandwidth, so this name will be different. I'll need to think of a better solution for this.