Cloth Asset - Crash when importing morph targets into clothing

UE - Simulation - Visual - Oct 20, 2025

The 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, 2025

The 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, 2025

GeometryCollectionPhysicsProxy::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, 2025

Geometry 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, 2025

The 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, 2025

Enabling 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, 2025

Fields 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 ...

Chaos Trailing Events not exposed to Blueprints and only accessible via Niagara Chaos DI

UE - Simulation - Visual - Apr 22, 2025

Chaos Trailing Events not exposed to Blueprints and only accessible via Niagara Chaos DI. The licensee noticed that the Trailing event is not available to BPs. It's expected that the same data avail ...

Each bone scales are improperly applied in the physical animation

UE - Simulation - Visual - Feb 4, 2025

Suggested fix from licensee is : PhysAnim.cpp@339 #if 0 FVector RelPos = RecipScale3D * RelTM.GetLocation(); #else FVector RelPos = (BoneIndex == 0) ? RecipScale3D * RelTM.GetLocation() : Rec ...

Capsule component renders incorrectly with non-uniform scale

UE - Simulation - Visual - Jan 30, 2025

Capsule component renders incorrectly with non-uniform scale because the render uses the minimum between the X and Y values and the collision code uses the maximum between the two. This issue is men ...