There is moving blotchy noise on the head and face from hair when Lumen HZB tracing hits hair. CL 33258050 fixes the noise in the hair, but tracing still hits hair when it starts from surfaces like the skin under the hair. For foliage we have
r.Lumen.ScreenProbeGather.ScreenTraces.HZBTraversal.SkipFoliageHits
to prevent this issue for grass and I think we need something similar for hair. In my tests modifying LumenScreenProbeTracing.usf so line 321 includes hair resolves the issue, though it's not a proper solution because it's gated by bSkipFoliageHits.
if (LumenMaterial.bHasBackfaceDiffuse || IsHair(LumenMaterial))
Expected
The shadow/ambient occlusion of the hair on the skin of the head and face is not noisy or moving.
Actual
There is moving blotchy noisy shadows on the head and face from the hair
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-215339 in the post.
0 |
Component | UE - Graphics Features - Lumen |
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Target Fix | 5.5 |
Fix Commit | 33855283 |
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Created | May 17, 2024 |
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Resolved | May 27, 2024 |
Updated | Jun 21, 2024 |