Lumen GI and Reflections feedback thread

[Daniel_Wright]

@Arkiras

Are there any plans to implement backscattering support for SSS materials in the surface cache? Noticed that this doesn’t work for Legacy or Substrate materials and screen traces are skipped for everything but subsurface profile.

Not at the moment. We’ve talked about it a lot, but there are some complications:

• Requires extra Surface Cache atlases to store ShadingModelId, Opacity, SubsurfaceColor. Lumen is already using too much VRAM, and the Surface Cache atlases don’t resize based on your use (hardcoded 4k^2), so we’d have to optimize elsewhere before we could do that.
• Trees (which the backface lighting would help) suffer from a bunch of other Surface Cache problems like missing coverage, so backface lighting is not the hardest thing that needs to be solved here.