TRAANode: New TRAA implementation.

[Mugen87]

Fixed #29842.

Description

The PR implements what has been suggested in #31361 (comment). TRAAPassNode is transformed to TRAANode so it is not an alternative to PassNode anymore. Now, you render a scene as always with pass() node and the common MRT settings. traa() is now added in the pass chain like ao(), ssr() or bloom() which makes it much more practical to use.

I've directly updated the AO demo to use TRAA instead of MSAA which brings the framerate back to 60 and also improves the overall AA quality.

@sunag I have not found yet an elegant way to integrate TRAA into PostProcessing. Right now, a separate call postProcessing.setTRAANode( traaNode ); is required to tell PostProcessing TRAA is in place. That is required so in render() the view offset (Jitter) can properly be configured. Is there a way to traverse the FX nodes so we can automatically detect an instance of TRAANode in PostProcessing?

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	338.01 78.83	338.01 78.83	+0 B +0 B
WebGPU	557.41 154.27	557.94 154.37	+528 B +93 B
WebGPU Nodes	556.33 154.05	556.86 154.17	+528 B +116 B

🌳 Bundle size after tree-shaking

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

	Before	After	Diff
WebGL	469.26 113.53	469.26 113.53	+0 B +0 B
WebGPU	633.24 171.4	633.24 171.4	+0 B +0 B
WebGPU Nodes	588.38 160.72	588.38 160.72	+0 B +0 B

[sunag]

@Mugen87 Why is there a vibration in the rendering now? I'm using pixel ratio 1, and it's quite noticeable.

[Mugen87]

It seems on dev, TRAAPassNode is broken since #31361 on my system with dpr of 2. And #31416 seems to broke the colors for the second cube. It currently looks like so:

I'll try to fix TRAANode before looking into TRAAPassNode but it seems the latest changes require more testing.

[sunag]

Maybe it's best to revert the #31361 PR for now. I have to check what happened, but opening it now I noticed that it's quite different.

If this PR takes a long time...

[Mugen87]

Sounds good! I'm not sure how long it takes to fix the instability issue.

[Mugen87]

Okay, the vibration should be fixed now. The behavior is now as before.

[sunag]

Okay, the vibration should be fixed now. The behavior is now as before.

Thanks @Mugen87.

I introduced onBeforePostProcessing() and onAfterPostProcessing() in the context of PostProcessing. They should be called after the second render, since the first one is still in the final stage of setup. I had to add a needsPostProcessingSync flag in TRAA to "synchronize" the first frame, but I'm not sure if it's the best way to fix this bug.

[Mugen87]

It's definitely a step forward compared to my initial approach since TRAANode is now less coupled with PostProcessing.