Unreal Engine Issues
Unreal Engine Issues
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 ...
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 ...
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 ...
Volumetric lightmap cache point becomes extreme bright if the light source is accidently at the exact(or almost) location of it
UE - Graphics Features - Aug 27, 2025UMG Retainer Box renders incorrect colors with Color Vision Deficiency enabled
UE - Editor - UI Systems - UMG - Aug 27, 2025When using a Retainer Box in UMG with Color Vision Deficiency enabled, the content inside the Retainer Box is rendered with incorrect colors compared to the rest of the UI. This bug is present in UE ...
BP Debugger: Unable to inspect debug data for ForEachLoop ArrayElement, Array_Get and Break Struct output pins
UE - Framework - Blueprint - Aug 26, 2025Context The blueprint debugger allows you to trigger breakpoints and inspect the current state of variables, both member variables, local variables and persistent UberGraph variables. Problem The ...
Geometry Collection cluster handles leaking and causing ensures with field systems
UE - Simulation - Visual - Aug 26, 2025Geometry Collection cluster handles leaking and causing ensures with field systems. The licensee has shared their analysis: We have been tracking down an assert that seems to happen occasionally wh ...
Cook non-determinism when serializing UObject pointers pointing to garbage
UE - CoreTech - UObject - Aug 25, 2025There's a cook determinism issue in the way UObject unversioned serialization handles UObject pointers pointing to garbage. Depending on GC timing, it can either be skipped (as a property matching C ...