Unreal Engine Issues
Unreal Engine Issues
Artifacts appear on translucent particle systems during camera motion blur
UE - Rendering - Architecture - Jul 23, 2025Translucent particle systems exhibit visual artifacts when the camera moves, even though motion vectors are disabled for the particle emitters. While switching the Translucency Pass to "After Motio ...
Local lights appear broken when baking lighting with GPU Lightmass
UE - Rendering - Features - Jun 2, 2025Encountered 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 ...
Multiple setter functions in UMaterialEditingLibrary always return false even when the parameter is correctly set on the MaterialInstance.
UE - Rendering - Architecture - Materials - May 30, 2025In Unreal Engine, materials can expose parameters that can then be modified via instances (MaterialInstanceConstant). The UMaterialEditingLibrary provides several functions to modify these parameter ...
Search field in 'Quickly Add to Project' fails with Chinese Pinyin input unless manually focused
UE - AI Workflows - UI Systems - Localization - May 28, 2025A licensee reported that under the Chinese language setting in UE5, using the “Quickly Add to Project” button results in incorrect or ignored input when entering text via Pinyin IME. If the user sta ...
Misaligned sampling in UI Material with with CustomStencil
UE - AI Workflows - UI Systems - May 19, 2025The output of the CustomStencil node in a User Interface material does not align with the viewport dimensions. Toggling fullscreen/windowed mode (F11) causes the offset to reappear, so scaling the n ...
Changes to Instanced Properties default value on BP not propagated to placed actors in the opened level
UE - Core - Systems - May 15, 2025In UE versions 5.4 and onwards (as of CL 42589677 in Main), when an Instanced UObject property is defined in an Actor Blueprint, modifying the default value in the Blueprint does not propagate the c ...
WidgetComponent is not updated with occlusion culling disabled
UE - Platform - XR - May 7, 2025LastRenderTime is never updated with occlusion culling disabled, so the widget component will always stop updating. (see UWidgetComponent::ShouldDrawWidget) Developers can force updates by TickWhen ...
Fields with Maximum resolution are not affecting all leaves of a Geometry Collection
UE - Runtime - Deformable - Apr 25, 2025Fields with Maximum resolution are not affecting all leaves of a Geometry Collection on 5.4 and onwards. When calling GetRelevantParticleHandles() a Maximum Resolution field does return all particl ...
Crash in GPUMessage.cpp when resetting FSocket when RHI is NullRHI.
UE - Rendering - RHI - Apr 5, 2025When tearing down a nanite project with the nullrhi active, there is a crash in the FeedbackManager destructor that causes any exit to be unclean. The teardown process causes a crash as the destruc ...
Crash trying to convert skeletal mesh to Nanite
UE - Rendering - Features - Nanite - Mar 6, 2025In SkeletalRenderNanite.cpp / FDynamicSkelMeshObjectDataNanite::UpdateBonesRemovedByLOD, bone indices are of type FBoneIndexType (defined as uint16 from BoneIndices.h), instead of int32. On line 18 ...