Unreal Engine Issues
Unreal Engine Issues
Landscape Layer Blending Painting Issue
UE - Graphics Tools - Terrain - Sep 10, 2025There are two issues when painting landscape layers.Paint: When painting between different layers, square-shaped artifacts or splotches appear.Fill Layer: The blended weights of other layers aren't ...
Iris - removal of fast array item not performed on client when server array contains a non-replicated item
UE - Networking - Iris - Sep 8, 2025It is possible to add items to a replicated fast array that are not intended to be replicated to the clients. For example, FGameplayAbilitySpecContainer has a custom ShouldWriteFastArrayItem impleme ...
Mover character stuck continuously correcting movement after having a skeletal mesh as movement base
UE - Gameplay - Player Movement - Mover - Sep 8, 2025Once a mover character has had a skeletal mesh set as its movement base, it appears to get stuck in a desynced state after moving to a static movement base. It is only when the character's movement ...
Crash when opening a texture or editing its properties after stopping a preview in the material editor
UE - Rendering Architecture - Materials - Sep 5, 2025When a texture asset has certain properties edited, its PostEditChangeProperty() method calls to UTexture::NotifyMaterials(), which triggers a recompilation of materials that reference it in their m ...
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 ...
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 - Visual - 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 ...
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 - Visual - Aug 30, 2025GeometryCollectionPhysicsProxy::FieldParameterUpdateCallback() not removing invalid Commands, leading to performance issues. The licensee has provided their analysis: We seem to have stumbled acro ...