Lumen GI and Reflections feedback thread

[Krzysztof.N]

@TheRealBiomes

Unfortunately doing this severely underoccludes the asset so we are left with a very flat looking foliage asset in our test cases, opposed to an overoccluded one. I strongly suggest considering adding a switch for this or generally looking at the described scenario; if most of the assets geometry has an opaque material assigned to it (what % I’m not sure of), any parts with a two sided foliage material will be overoccluded. Lumen weakens the distance fields when the ratio is within a certain range, but this doesn’t take into account not all meshes will fit in that range.

I see, so to make sure, you are looking here for a three state switch: [auto, two-sided, one-sided] instead of a current checkbox “Generate as two-sided”?

@TheKJ

A Cvar that would really help things out would to limit reconstruction from Bilateral and Reconstruction samples from affecting lower roughness like 0.0, 0.01.

That’s an interesting point. We have something similar in reflections, where reconstruction and bilateral filters are scaled by roughness, and temporal accumulation is reduced for mirror like surfaces. I’ve made a note to look into it to see if it can be improved.

@TheKJ

Lumen Reflections do not jitter in a way where 0.0 reflections can be constructed to the main internal resolution as frames pass on low roughness, if they were, we could get high res reflections in around 5 frames. I guess this was unfortunately handed off too.

We already have jitter from screen pixels and not sure what else could be jittered for roughness=0.