Local lights appear broken when baking lighting with GPU Lightmass

UE - Graphics Features - Jun 2, 2025

Encountered an issue where local lights appear to be broken when baking lighting with GPU Lightmass. See screenshots attached. Tested regression in //UE5/Release-5.5 @ CL40574608 and the issue does ...

Virtual Bone caused nanite skinned mesh crash

UE - Graphics Features - Nanite - May 31, 2025

When a Nanite skeletal mesh has a virtual bone the engine can crash when changing LODs ...

Multiple setter functions in UMaterialEditingLibrary always return false even when the parameter is correctly set on the MaterialInstance.

UE - Rendering Architecture - Materials - May 30, 2025

In Unreal Engine, materials can expose parameters that can then be modified via instances (MaterialInstanceConstant). The UMaterialEditingLibrary provides several functions to modify these parameter ...

TSR and TAA history accumulation gets reset when taking viewport screenshots or when clicking outside the tree in the outliner

UE - Graphics Features - May 30, 2025

TSR (and TAA) history accumulation gets reset when taking viewport screenshots or when clicking on an empty area in the outliner (when a tree item is selected). This can cause an undesirable issue w ...

GLTFExporter indexing issue

UE - Editor - Content Pipeline - glTF - May 29, 2025

Hi, I also ran into an issue when exporting a skeletal mesh that has multiple sections that all share the same material slot. It looks like the index buffer that's constructed is incorrect. In GLTF ...

Live Link Hub hang when discovering YUV444 encoded takes in Capture Manager

UE - Virtual Production - IO - LiveLink - May 28, 2025

When using Capture Manager in Live Link Hub to discover takes which contain video encoded with the YUV444 pixel format will cause the application to hang. The Windows Media Foundation library used ...

VSM SMRT SamplesPerRay CVars behave differently if groom assets are present leading to a potential full-scene shadow

UE - Graphics Features - May 28, 2025

When a groom is present, setting any SamplesPerRay SMRT CVar to zero results in an unexpected complete shadow projected from the light. ProjectLight() in VirtualShadowMapProjection.usf has addition ...

MRQ - No Rayrtaced Shadows casted from Groom Caches with only 1 Spatial Sample

UE - Anim - Sequencer - MRQ - May 28, 2025

A groom cache will not cast a raytraced shadow with only 1 spatial sample. It does not matter how many temporal samples you have. ...

Rendering of a Text Widget with Outline does not track LayerId correctly

UE - Editor - UI Systems - May 27, 2025

Text widget with Outline uses 2 LayerId levels to draw the outline and the text glyphs. This can be seen in function FSlateElementBatcher::AddShapedTextElement(), where lambda BuildFontGeometry() is ...

Virtual Shadow Maps on Spot Lights cause a blocky presentation similar to an incorrect mip level

UE - Graphics Features - Shadows - May 26, 2025

Spot Lights may present with very blocky shadow artefacts when a long attentuation radius is provided with a small cone angle. In extreme cases, this causes the VSMs to invalidate every frame. Notab ...