NodeMaterial: Use materialReference() for env maps.

[Mugen87]

Related issue: -

Description

It is currently not possible to dynamically update material.envMap: https://jsfiddle.net/br8ezgfw/1/

That works in WebGLRenderer and it also works to exchange normal textures (e.g. material.map) with WebGPURenderer .

The issue can be resolved by using materialReference() when setting up the env node in NodeMaterial but that leads unfortunately to a cyclic dependency:

src/nodes/accessors/MaterialNode.js -> 
src/nodes/accessors/ReferenceNode.js -> 
src/nodes/accessors/CubeTextureNode.js -> 
src/nodes/accessors/ReflectVectorNode.js -> 
src/nodes/accessors/MaterialNode.js

@sunag I wonder if you have any ideas to solve this issue. What I find not optimal is the fact that CubeTextureNode.getDefaultUV() has a material dependency since refractVector relies on the refraction ratio of the material.

Would it be an option to move the uv computation into the place where the sampling actually happens (that is BasicLightingModel)? However, without proper default uvs, it might be inconvenient to use cubeTexture() elsewhere in the code base and on app level.

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

Filesize dev	Filesize PR	Diff
684 kB (169.4 kB)	684 kB (169.4 kB)	+0 B

🌳 Bundle size after tree-shaking

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

Filesize dev	Filesize PR	Diff
460.9 kB (111.2 kB)	460.9 kB (111.2 kB)	+0 B

[sunag]

A few time ago I started this approach #28422 avoiding classes and directing everything to the TSL approach, there are certainly a lot of classes to review with this.

[Mugen87]

FYI: I had to add this check otherwise PMREM generation was broken.

[Mugen87]

Exchanging the env map for basic, lambert and phong works now as expected. Great!

However, EnvironmentNode needs an enhancement since the PMREM isn't regenerated when envMap is changed.

updateBefore() might be a good spot for checking the status but I'm not sure how to access the material without the builder reference. Besides, ideally we only update the PMREM node without regenerating the radiance and irradiance node. Is that even possible?

[sunag]

It seems like having a reference()/materialReference() supporting pmrem we could be removed this cacheEnv using MeshStandardNodeMaterial.setupEnvironment() for create this.

[Mugen87]

Let's tackle this in a different PR.