Unreal Engine Issues

Distance field PrimitiveModifiedBounds grows unbounded when scene captures render with bDisableWorldRendering=true

When UGameViewportClient::bDisableWorldRendering is true and the scene is rendered only through manually triggered scene captures, FDistanceFieldSceneData::PrimitiveModifiedBounds is never reset and ...

ResolvedView.DirectionalLightColor and DirectionalLightDirection go black when one of several directional lights is removed from the scene

With more than one directional light in the scene, ResolvedView.DirectionalLightColor and ResolvedView.DirectionalLightDirection can report the wrong light, or black and a zero vector, while a direc ...

Motion blur artifacting in MetaHuman Crowd demo

This issue was reported by a licensee and we also hit it during dev work on the crowds demo. It seems that this may be a general issue with motion vectors and teleporting actors as there are variou ...

SplineMeshComponent resources leak

A race condition occurs in the InitSplineVertexFactory_Internal }}function call, which is distributed across multiple threads. This causes {{FSplineMeshVertexFactory to be instantiated multiple time ...

Brick Pattern Artifact in Volumetric Clouds

A licensee has reported seeing a repeating brick-like pattern in volumetric clouds when they overlap with very distant geometry (or at the transition between nearby and distant geometry). The artifa ...

VSM shadows are missing for non-Nanite meshes in a PPV where Megalights is disabled, but Megalights is enabled in the project

In UE 5.8 r.Visibility.LocalLightPrimitiveInteraction mode 2 (enabled if MegaLights is disabled) was added and made the new default as a performance optimization. However, this causes shadows to d ...

Translucent meshes randomly flicker when using VSM

Flickering can occur on translucent materials, usually in the distance when there is at least one directional light and when using VSM. Flickering seems highly dependent on framerate and timing. L ...

Assert crash when playing Groom Cache with Card Mesh LOD

Playing a Guides Groom Cache while Card Mesh LOD (Guide-Based) is active causes an assert in RunHairStrandsInterpolation_Cards when the renderer switches to Card LOD. Assert location:Plugins/Runtim ...

VSM + Nanite Tessellation + Volumetric Fog Shadow leaking while the Directional lighting is rotating

ApplyLocalExposure uses Output_ExtentInverse instead of Output_ViewportSizeInverse for bilateral grid UV

The ApplyLocalExposureCS shader in PostProcessLocalExposure.usf computes UV coordinates for the LumBilateralGrid 3D texture using Output_ExtentInverse (1/RenderTargetSize) instead of Output_Viewport ...