SpotLightShadow: Introduce aspect property

[sunag]

Related issue: #31013 (comment)

Summary

• SpotLightShadow: Introduce aspect
• improve custom aspect example
• TSL: Fix convert .set*() value to node-object

Example 1

Example 2

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	336.33 78.33	336.33 78.33	+0 B +0 B
WebGPU	547.81 151.88	547.81 151.89	+4 B +1 B
WebGPU Nodes	547.16 151.73	547.16 151.73	+4 B +1 B

🌳 Bundle size after tree-shaking

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

	Before	After	Diff
WebGL	465.78 112.28	465.78 112.28	+0 B +0 B
WebGPU	622.66 168.44	622.7 168.46	+30 B +11 B
WebGPU Nodes	577.54 157.71	577.57 157.72	+30 B +14 B

[WestLangley]

I think the aspect should be automatic: set to 1 if there is no texture, and equal to the texture's aspect otherwise. There is no need for a separate aspect property.

[sunag]

I think the aspect should be automatic: set to 1 if there is no texture, and equal to the texture's aspect otherwise. There is no need for a separate aspect property.

I think it could be useful for rectangular lighting.

[WestLangley]

I think it could be useful for rectangular lighting.

I do not think that is necessary.

[WestLangley]

Also, I think a rectangular projection is a bit too complex to ask a user to implement themselves in TSL, and it should be a built-in feature like "focus" and "penumbra".

Support for "cookies" would also be a reasonable built-in feature for a spotlight.

[sunag]

Support for "cookies" would also be a reasonable built-in feature for a spotlight.

What would be support for cookies?

[WestLangley]

What would be support for cookies?

Here is a good explanation: https://docs.unity3d.com/Manual/Cookies-introduction.html.

[WestLangley]

TSL is great. However, I do not see it as the best solution for the "projector light" use case. Users should not have to code this particular feature themselves, IMHO.

[sunag]

Here is a good explanation: https://docs.unity3d.com/Manual/Cookies-introduction.html.

It seems like the article is talking about shadow baking like this and light.map features, but maybe there's something more there?

The idea of ​​a projector is interesting especially if we integrate it with a light.colorNode.

[sunag]

I'm going to merge this PR and will work on creating a ProjectorLight that supports procedural shader, it seems like a good opportunity.

[WestLangley]

Cookies can have an alpha channel, which can be used to attenuate the intensity.

Here is another example: https://developer.playcanvas.com/tutorials/light-cookies/

I'm going to merge this PR and will work on creating a ProjectorLight

A projector light that projects a movie would be good. It should just work, without the user have to write TSL to make it work.