Unreal Engine Issues
Unreal Engine Issues
Lack of multi-bounce when using software traced lumen radiosity
UE - Graphics Features - Lumen - Apr 4, 2025Certain Lumen Hardware Ray Tracing CVars, when disabled in isolation, will not fall back to tracing the Global Distance Field, because the Global Distance Field is still disabled. The function "Lum ...
Skylighting on distant objects causes severe flickering with Lumen
UE - Graphics Features - Lumen - Mar 31, 2025Lighting on distant meshes flickers when using Lumen and Skylights. Turning Lumen off and lighting from the skylight is stable. Turning off Lumen screen traces also lowers the amount of flickering ...
r.Lumen.Reflections.DownsampleFactor split screen artifact
UE - Graphics Features - Lumen - Dec 6, 2024In Split-Screen, with "r.Lumen.Reflections.DownsampleFactor" set to 2, it is possible to have vertical colored artifacts on View 1 (the second view). The Licensee reported the artifact occurred on ...
Lumen temporal flicker after leaving Editor open for 3+ days
UE - Graphics Features - Lumen - Nov 18, 2024Lumen GI has temporal flickering/noise after running the Editor for 3+ days. ...
Lumen doesn't handle Area Lights Reflection Occlusion well
UE - Graphics Features - Lumen - Oct 18, 2024Ghosting effect of fast moving objects in Lumen
UE - Graphics Features - Lumen - Oct 15, 2024Lumen doesn't use correct sky light settings when GI scalability changes from Low to High
UE - Graphics Features - Lumen - Sep 24, 2024When the Global Illumination scalability settings are changed in the editor from High to Medium, they primarily act on the r.Lumen.DiffuseIndirect.Allow and r.SkyLight.RealTimeReflectionCapture. No ...
Lumen interior light leaking occurs with realistic sun Lux values (20k)
UE - Graphics Features - Lumen - Aug 23, 2024When a realistic sun Lux value of 20,000 for the sun directional light, interior light leaking is much more pronounced then when using the default directional light Lux value of 10 Lux. ...
Thin Translucent rendering output is different on UnrealEditor/PC and PS5 with Ray Tracing enabled
UE - Graphics Features - Lumen - Aug 8, 2024Reported from UDN With RT Translucency and Reflections enabled, Thin Translucent rendering is incorrect on PS5 in UE 5.3 ...
Screen Probes and Specular Firefly Flickering near screen edges
UE - Graphics Features - Lumen - Aug 6, 2024Lumen's rough specular indirect lighting buffer can have fireflies along the bottom and right edges of the screen. Also tested in //UE5/Main, CL: 35177423 ...