Unreal Engine 5.1 RTX GI artifacts

Found some artifacts from RTX GI in UE5.1

Simple shader (texture is default one - MaterialError):

It’s not just viewport, it’s on render too. Tested in UE4.27 - no artifacts.

Example project (just open the project and open level “CursedRTXGI”):
CursedRTXGI.z01 (25 MB)
CursedRTXGI.zip (18.7 MB)

Steps to reproduce:

  • create a new project

  • add postprocess volume:
    Infinite Extent (Unbound)
    GI Method = Standalone Ray Tracing
    RT GI Type = Brutforce
    RT GI Max Bounces = 4

  • setup directional light properties:
    intensity = 15
    Indirect Lighting Intensity = 150