Unreal Engine Issues
Unreal Engine Issues
Cloth - Assertion failed: SimData->LODIndex != INDEX_NONE && SimData->LODIndex <= LOD when using the rewind debugger with multiple LODs cloth
UE - Simulation - Visual - Feb 19, 2026The LOD switching when the simulation is paused could still be causing problems when the simulation is paused while the LOD indexes are going up because there is no LOD Bias mappings by default. Se ...
Chaos Cloth - Multiple issues with convex colliders
UE - Simulation - Visual - Feb 6, 2026Issue 1: Convex Collision Transformation Missing for External Collision Sources Issue 2: Convex CCD Stability Issues due to Plane Intersection Semantics See attached URL for more details. ...
Chaos Cloth Asset - Wrong vertex colors imported from the StaticMeshImport node.
UE - Simulation - Visual - Jan 22, 2026The StaticMeshImport and SkeletalMeshImport nodes don’t have the correct vertex colors imported into the Cloth Asset. ...
Cloth Asset - Crash when importing morph targets into clothing
UE - Simulation - Visual - Oct 20, 2025The sim morph import has been broken after a change to make it work for cooked assets. Ticking the Import Sim Morph Targets checkbox crashes as soon as a skeletal mesh with morph target is specifie ...
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 ...
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 ...
The Geometry Collection Dataflow node CreateGeometryCollectionFromSources is breaking Material Assignment
UE - Simulation - Visual - Jul 21, 2025The Geometry Collection Dataflow node CreateGeometryCollectionFromSources is breaking Material Assignment. As the licensee has pointed out, this previously worked in 5.5. The most probably cause fo ...
Enabling bUpdateComponentTransformToRootBone in a GeometryCollectionComponent causes broken particles to appear in the wrong location
UE - Simulation - Visual - Jun 22, 2025Enabling bUpdateComponentTransformToRootBone in a GeometryCollectionComponent causes broken particles to appear in the wrong location. When that flag is true, the moment the GeometryCollection (GC) ...
Fields with Maximum resolution are not affecting all leaves of a Geometry Collection
UE - Simulation - Visual - 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 ...