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

UE - Rendering - Features - Sep 25, 2026

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 ...

ReturnUntouchedSceneColorForPostProcessing ignores view overrides and breaks splitscreen

UE - Rendering - Architecture - Sep 17, 2026

When a view extension uses ReturnUntouchedSceneColorForPostProcessing and uses split screen, the final view is incorrect (clipped) because ReturnUntouchedSceneColorForPostProcessing doesn't take int ...

SplineMeshComponent resources leak

UE - Rendering - Features - Aug 3, 2026

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

Non-Nanite meshes not being correctly cleared from all levels of VSMs on actor destruction when r.Shadow.Virtual.NonNanite.IncludeInCoarsePages=0

UE - Rendering - Features - Shadows - Jun 15, 2026

When using the r.Shadow.Virtual.NonNanite.IncludeInCoarsePages=0 to optimize VSM performance there are errors in how the VSM is invalidated when actors are destroyed with non-Nanite meshes. The curr ...

Crash when applying Decal material with Distance Cull Fade node to Decal Actor

UE - Rendering - Architecture - Materials - Jun 15, 2026

The Editor crashes when applying a Material with a Distance Cull Fade node to a Decal Actor. Fatal error: [Link Removed] [Line: 730] Missing uniform buffer at slot 2, stage SF_Pixel. Please check ...

check(bRenderStateCreated) fires in SendRenderDynamicData_Concurrent called from FRegisterComponentContext::Process

UE - Rendering - RHI - May 18, 2026

FRegisterComponentContext::Process() in ActorComponent.cpp iterates over SendRenderDynamicDataPrimitives and calls SendRenderDynamicData_Concurrent() on each. The existing guard checks ::IsValid(Pri ...

Wrong WPO motion vectors due to Periodic World Space node

UE - Rendering - Features - May 13, 2026

We've noticed smearing in grass due to wrong motion vectors. This appears to be caused by lack of previous frame support in the periodic world space node. This is how we fixed it: In MaterialTempl ...

Curve Atlas Row Parameter uses derivative ops when Texture Sample connected to curveTime input

UE - Rendering - Architecture - Materials - May 1, 2026

When a Curve Atlas Row Parameter node is used with a Texture Sampler connected to the curve time input, the sample type uses derivative ops. This has negative performance implications for Nanite co ...

Cursor radius set via FSlateApplication::SetCursorRadius is ignored during FHittestGrid hit testing

UE - AI Workflows - UI Systems - Slate - Mar 16, 2026

The cursor radius configured through FSlateApplication::SetCursorRadius() is not respected during Slate hit testing. The radius value is correctly stored in FSlateApplication and passed into FHittes ...