Lumen doesn't use correct sky light settings when GI scalability changes from Low to High

UE - Graphics Features - Lumen - Sep 24, 2024

When 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, 2024

When 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, 2024

Reported 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, 2024

Lumen'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 ...

Memory leak when Lumen is disabled but r.MeshCardRepresentation=1

UE - Graphics Features - Lumen - Jul 29, 2024

When Lumen is disabled, but the cvar "r.MeshCardRepresentation" is set to 1, Lumen will continuously enqueue object removal from the Lumen Scene, without ever emptying the array of primitives to rem ...

Lumen reflection distortion

UE - Graphics Features - Lumen - May 30, 2024

Lumen reflections appear distorted depending on the camera orientation. ...

Lumen screen traces from hair cast noising moving shadows on faces

UE - Graphics Features - Lumen - May 17, 2024

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 ...

Color shifting occurs from screen probe gather ping-pong when Lumen active

UE - Graphics Features - Lumen - Apr 29, 2024

A subtle yellow tint color shift occurs when Lumen is active due to usage of R11G11B10_Float targets, mostly from r.Lumen.ScreenProbeGather.SpatialFilterProbes where we ping-pong between R11G11B10_F ...

Masked TwoSided material causing lumen direct lighting to leak through walls

UE - Graphics Features - Lumen - Apr 23, 2024

It appears that LumenScene's Hardware Ray Tracing is causing light leaking into a sealed room (which should be perfectly black). This bug does not appear to happen on AMD GPUs. ...

Lumen artifacts on splitscreen during camera cuts

UE - Graphics Features - Lumen - Apr 18, 2024

A UDN licensee has pointed out that they are seeing unresolved Lumen reflection artifacts when they are running their game in split-screen mode. A video of this behavior is found in the Related tab ...