PMREMGenerator extension: Now you can set texture size and position

[Spiri0]

Related issue: #30071

I have modified the PMREMGenerator so that you can now change the texture size and position. To do this, I changed the values ​​to a parameter list. In my opinion, that makes more sense than having to constantly hand over all the values. This way you only need to specify the ones you want to change. Otherwise you would have to fill the empty spaces with undefined.
This change made it necessary to also adapt the examples webgpu_ocean, webgpu_postprocessing_ao, webgpu_postprocessig_ssr

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	336.25 78.28	336.39 78.31	+131 B +33 B
WebGPU	505.56 140.43	505.69 140.45	+131 B +25 B
WebGPU Nodes	505.03 140.32	505.16 140.35	+131 B +25 B

🌳 Bundle size after tree-shaking

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

	Before	After	Diff
WebGL	465.25 112.13	465.38 112.16	+132 B +36 B
WebGPU	579.6 157.12	579.73 157.15	+132 B +31 B
WebGPU Nodes	534.98 146.67	535.11 146.7	+132 B +29 B

[Mugen87]

Please add the size and position to the PMREMGenerator of WebGLRenderer as well.

three.js/src/extras/PMREMGenerator.js

Line 112 in a13e4b0

fromScene( scene, sigma = 0, near = 0.1, far = 100 ) {

[Spiri0]

I'll take care of it over the weekend, luckily it's a small thing

[Spiri0]

I remember how Sunag adjusted these lines to fix the reflection error. These were still at the old status in the webgl PMREMGenerator. I also adjusted that straight away. I see that no environment is rendered in the webgl_pmrem_test as was previously the case with the webgpu pmrem example. Therefore, this will never have been noticed.

const upSign = [ 1, 1, 1, 1, - 1, 1 ];
const forwardSign = [ 1, - 1, 1, - 1, 1, - 1 ];

[Mugen87]

const upSign = [ 1, 1, 1, 1, - 1, 1 ];
const forwardSign = [ 1, - 1, 1, - 1, 1, - 1 ];

Do you mind revert this change in src/extras/PMREMGenerator.js? I'm not sure it is correct since WebGPURenderer uses a different coordinate system and that might cause different signs in the WebGPU version of PMREMGenerator. Let's investigate this separately.

[Spiri0]

No problem, I'm happy if I can contribute something to the project, even if it's not much.

[sunag]

Couldn't we have these properties in class scope? e.g:

const sceneRT = new THREE.PMREMGenerator( renderer );
sceneRT.position = new THREE.Vector3( ... );
sceneRT.faceSize = 256;
sceneRT.fromScene( ... )

Maybe we will have more options in the future, that should help.

[Mugen87]

position and size are only relevant for fromScene() and have no purpose for the rest of the API. Hence, I would favor to keep both in the method signature. As a compromise, how about doing the following?

generator.fromScene( scene, sigma, near, far, options );

In this way, we can add position, size and potentially future configuration properties to options.

[sunag]

Sounds good to me.