Description

When skylight raytracing is enabled, and skylight mobility is movable, skylight diffuse convolution is used on top of the skylight diffuse raytracing, causing severe bias and incorrect raytraced results.

 

Attached is a link to the sample project provided from the user: 

[Link Removed]

Steps to Reproduce
  1. Open any project with interior space
  2. Disable all raytracing features except skylight raytracing and ray traced reflections (Turn of ray traced AO, and ray traced GI)
  3. In PostProcess volume, set Ray Traced reflections max roughness value to 1 (To prevent rough rays rejection and reduce bias for comparison)
  4. Position view inside of the interior space, and toggle skylight mobility between static, stationary and movable.

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Won't Fix
ComponentUE - Graphics Features - Lumen
Affects Versions4.234.244.22.34.25
CreatedOct 28, 2019
ResolvedAug 27, 2021
UpdatedSep 19, 2021