Unreal Engine Issues
Unreal Engine Issues
Reflection capture doesn't work when using Lumen GI and SSR
UE - Rendering - Architecture - Mar 24, 2025Reflection Capture does not appear to work with Lumen + SSR. Licensees have reported that there are cases where they want to combine Lumen GI, SSR and Reflection capture for quality and performance ...
Crash when Undo after deleting a Material Layer of a Material Instance.
UE - Rendering - Architecture - Materials - Apr 2, 2025In Unreal Engine version 5.5.4, the Editor crashes when performing Undo after deleting a Material Layer of a Material Instance ...
Nanite TwoSidedSign is backwards
UE - Graphics Features - Nanite - Apr 10, 2025The value of MaterialExpressionTwoSidedSign is flipped when calculating the Opacity Mask for Nanite meshes. This seems to be a regression in 5.5. ...
Ensure triggered when creating Scene Proxy for GroomComponent
UE - Rendering - Architecture - RHI - Apr 30, 2025When a room component is added in C++ via the actor constructor, an ensure is triggered from precaching and the groom component. Behavior also observed on UE5/Release-5.5, CL: 40988944 ...
Lightmaps are generated even if the ISM component's lightmap type is set to Force Volume
UE - Graphics Features - Jul 30, 2024Insufficient precision of Decode71 function
UE - Rendering - Architecture - Shaders - Jun 5, 2025Encode71 and Decode71 in DeferredShadingCommon.ush are functions that convert 8-bit values to 7-bit values and mask values, and licensees have reported that the accuracy is insufficient when usi ...
Niagara mesh particles invalidate lighting when "Cast Shadow" is enabled with Hardware Ray Tracing enabled
UE - Rendering - Graphics Features - Lumen - Jun 24, 2025Lumen HWRT, combined with Niagara Mesh Renderer, can cause the Lumen Scene to be reset, resulting in a sudden change to indirect lighting. ...
CPU Lightmass generates different lighting results on a landscape if executed via a commandlet vs through the editor
UE - Graphics Features - Jul 3, 2025Building lighting via commandlet and via editor are giving different results. To prevent one method from polluting the other via Swarm cache, the cache needs to be cleared in between tests. ...
DistanceToNearestSurface node does not work when r.DistanceFieldAO is disabled
UE - Rendering - Architecture - Materials - Jul 16, 2025The problem seems to be that the bUsesGlobalDistanceField flag in the ShouldPrepareGlobalDistanceField() function checks for usage on the material, but it doesn't seem to take effect. The material u ...
Rect Light not rendered correctly when using Virtual Texture as source texture
UE - Graphics Features - Aug 14, 2025Licensees have reported that this issue occurs when rendering from the command line: Rectangular lights with virtual textures do not render when you run the "Render (Remote)" button in the Editor, a ...