Renderer: Rename shadowMap.colored -> shadowMap.transmitted

[sunag]

Related issue: https://github.com/mrdoob/three.js/pull/32608/changes#r2641749091

Description

The term transmitted should imply that the shadow should somehow consider the transmission of light in non-opaque materials. It follows the physical principle more than the subjective like the previous one.

This should prepare three.js when we implement this in native materials; currently, the process is done manually through material.castShadowNode, and since this feature requires an extra texture per shadow, for optimization it comes disabled.

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	355.34 84.47	355.34 84.47	+0 B +0 B
WebGPU	618.88 171.9	618.89 171.91	+16 B +3 B
WebGPU Nodes	617.48 171.65	617.5 171.66	+16 B +4 B

🌳 Bundle size after tree-shaking

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

	Before	After	Diff
WebGL	487.5 119.33	487.5 119.33	+0 B +0 B
WebGPU	691.14 187.55	691.15 187.55	+16 B +6 B
WebGPU Nodes	640.98 174.78	640.99 174.78	+16 B +3 B

[Mugen87]

Regarding the discussion in https://github.com/mrdoob/three.js/pull/32608/files#r2641143718, I'm okay with whatever you and @WestLangley think is best^^.

[WestLangley]

I'm okay with whatever you and @WestLangley think is best^^.

@Mugen87 This property, including its name, precisely what it is for, and when it must be set to true, is still a mystery to me.

For now, I am going to assume it is a work-in-progress.