Nanite TwoSidedSign is backwards

UE - Graphics Features - Nanite - Apr 10, 2025

The 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, 2025

When 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 ...

Insufficient precision of Decode71 function

UE - Rendering - Architecture - Shaders - Jun 5, 2025

Encode71 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, 2025

Lumen 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, 2025

Building 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, 2025

The 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, 2025

Licensees 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 ...

Hovering items at bottom right of Content Browser does not display tooltip and causes cursor flicker

UE - Editor - Sep 17, 2025

When hovering over items located at the bottom right corner of the Content Browser while the Editor is maximized, the tooltip is not displayed. It seems that the tooltip would extend beyond the edge ...