II’m experiencing a rendering artifact in UE 5.7 that I can’t resolve.
Setup:
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Substrate material with Clear Coat layer
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Lumen Hardware Ray Tracing reflections enabled
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“Max Roughness to Trace” set to anything other than 0.2 (e.g., 0.4, 0.6, 0.8)
Issue:
A small colorfill square / tile artifact appears on screen. It stays fixed in the same place (not moving with geometry). Disabling Hardware Ray Tracing makes it disappear. Switching reflections to Screen Space turns the square black.
What I’ve tried (none worked):
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Updated the BIOS of my Motherboard
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Updated NVIDIA driver to latest
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Deleted Intermediate, Saved, DerivedDataCache
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Tried console variables:
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r.Lumen.Reflections.MaxRoughnessToTraceClamp 0 -
r.Lumen.Reflections.Temporal.NeighborhoodClampScale 0 -
r.Lumen.Reflections.SamplePerPixel 1 -
r.Lumen.Reflections.SpatialFilter 0 -
r.Lumen.Reflections.RadianceCache 0 -
r.LumenScene.Radiosity.ProbeSpacing 2 -
r.raytracing.nanite.mode 1
-
-
The artifact remains. Only setting
r.Lumen.Reflections.Temporal 0changes it from a square to a bloom flare (not a fix).
Question:
Is this a known Substrate + Clear Coat + Lumen HWRT bug in 5.7? Are there any working workarounds besides disabling Substrate or lowering Max Roughness?
Thanks for any help.
