Unreal Engine Issues
Unreal Engine Issues
PoseSearch Query is flipped 180 degrees 1 frame after a capsule/actor rotation happens.
UE - Anim - Gameplay - Sep 3, 2025Using MotionMatching with a PoseSearchSchema with a Trajectory grouping. The query gets rotated to match the capsule/mesh component instead of the offset root/actual location of those bones/trajecto ...
Invalid GUIDs on new material instance parameters cause overrides to break on base param rename
UE - Rendering Architecture - Materials - Sep 3, 2025When a parameter value is assigned on a newly created material instance (constant or dynamic) using Set***ParameterValueInternal, the parameter’s ExpressionGUID is left invalid (0,0,0,0). Parameter ...
RigVMRegistry : The registry is not locked for writing yet : ensure statement error during cook
UE - Anim - Rigging - Control Rig - Sep 2, 2025I am seeing an cook failure at the very beginning. It goes away with a retry step via Horde. Please find attached call stack. I am able to consistently reproduce it by wiping all the DDC cache and ...
Precision issues with 16-bit Skin Cache shaders.
UE - Rendering Architecture - Sep 2, 2025A licensee reported precision issues with position in the gpu skin cache shaders with 16-bit real types enabled. ...
Negatively scaled box collisions render back faces in Player Collision debug view
UE - Simulation - Physics - Sep 1, 2025The player collision debug visualization for negatively scaled boxes is rendering the back faces, not the front faces. The debug primitives are rendered via the dynamic mesh builder. FDynamicMeshBui ...
When ControlRig.EnableAnimNodePerformanceOptimizations is enabled, the default pose briefly appears after the Control Rig is reinitialized
UE - Anim - Rigging - Control Rig - Sep 1, 2025Since UE5.6, ControlRig.EnableAnimNodePerformanceOptimizations is enabled by default, and this appears to be causing the issue. Specifically, when the control rig’s construction event is processed, ...
Crash when running "MAP REBUILD ALLVISIBLE" with hidden sublevels and then changing maps
UE - World Creation - Worldbuilding Tools - Sep 1, 2025Running the MAP REBUILD ALLVISIBLE editor command when the current map contains hidden sublevels causes a crash upon changing maps. The issue seems to be related to hidden sublevels being cleared in ...
Hardware Lumen Surface Cache Artifacts on Nanite Geometry
UE - Graphics Features - Lumen - Sep 1, 2025When using Hardware Lumen with Nanite-enabled meshes in UE 5.6+, black / dark surface cache artifacts appear that result in generally darker and unstable lighting. These artifacts are not immediatel ...
GeometryCollectionPhysicsProxy::FieldParameterUpdateCallback() not removing invalid Commands, leading to performance issues
UE - Simulation - Physics - Destruction - Aug 30, 2025GeometryCollectionPhysicsProxy::FieldParameterUpdateCallback() not removing invalid Commands, leading to performance issues. The licensee has provided their analysis: We seem to have stumbled acro ...
Material Particle SubUV Sample does not work with Tex Object
UE - Rendering Architecture - Materials - Aug 29, 2025The Particle SubUV Sample node uses its own texture object reference instead of the one provided by the texture object node. ...