WebGLRenderer: Refactor setRenderTargetTextures().

[cabanier]

Move more logic to resolveDepthBuffer instead of relying on an undefined depth buffer

This contribution is funded by Meta

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	336.16 78.31	336.01 78.26	-144 B -52 B
WebGPU	522.67 145.12	522.67 145.12	+0 B +0 B
WebGPU Nodes	522.14 145.01	522.14 145.01	+0 B +0 B

🌳 Bundle size after tree-shaking

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

	Before	After	Diff
WebGL	465.22 112.18	465.07 112.13	-144 B -53 B
WebGPU	593.09 160.72	593.09 160.72	+0 B +0 B
WebGPU Nodes	548.22 150.16	548.22 150.16	+0 B +0 B

[Mugen87]

It seems this PR breaks transmission. There is no refraction anymore in webgl_loader_gltf_transmission:

[cabanier]

@Mugen87 Strange, it looks correct on my end with my change.

Maybe I need to rebase?

[Mugen87]

I have tested on macOS with Chrome. The CI uses puppeteer + Windows. Here are the actual and expected screenshots from the CI for webgl_loader_gltf_transmission:

Actual:

Expected:

Other affected demos are webgl_loader_gltf_anisotropy and webgl_loader_gltf_iridescence.

Maybe I need to rebase?

This can't hurt. On which device/browser have you tested with?

[cabanier]

Maybe I need to rebase?

This can't hurt. On which device/browser have you tested with?

I'm using Chrome on mac

[cabanier]

@Mugen87 the transmission render target has resolveDepthBuffer set to false. Shouldn't that be true? Don't we need the depth?

[Mugen87]

When I recall correctly only the color is needed. The depth discard was originally implemented in #28132 and later refactored via #28170 so resolveDepthBuffer is used.

/cc @mrxz

[cabanier]

I removed the change in WebGLTextures.js that caused this regression.

[mrxz]

When I recall correctly only the color is needed.

Indeed, only the color is used for transmission. Even when refracting, the refracted ray is just used to approximate where to sample (see transmission_pars_fragment.glsl.js#L210-L218)