Creating a GeometryCollectionActor from a GeometryCollectionAsset is ignoring some of the data set in the asset

UE - Simulation - Physics - Mar 13, 2025

When you create a GeometryCollectionActor by dragging a GeometryCollectionAsset from the ContentBrowser into the scene, instead of using the PhysicsMaterial defined in the GeometryCollectionAsset, i ...

Physics Constraint Component loss of accuracy

UE - Simulation - Physics - Mar 6, 2025

Physics Constraint Component has lost accuracy between Unreal versions 5.2 and 5.4 (and up). When measuring the exact distance between rigid bodies constrained by a Physics Constraint Component, the ...

Autobrake feature in ChaosVehicleMovementComponent is stopping vehicle from sleeping

UE - Simulation - Physics - Mar 5, 2025

In ChaosVehicleMovementComponent::CalcThrottleBrakeInput, autobrake is set when a vehicle is stopped - this means that when the car is virtually stationary, the BrakeOut inout parameter is always 1. ...

OnComponentWake Event does not trigger when the physical body is awoken by a Force

UE - Simulation - Physics - Feb 27, 2025

OnComponentWake Event does not trigger when the physical body is awoken by a Force. The steps described on Steps To Reproduce is enough to replicate this behavior. The OnComponentWake event is only ...

Chaos Modular Vehicles Examples desynchronizes easily

UE - Simulation - Physics - Feb 27, 2025

Chaos Modular Vehicles Examples does not replicate properly and it's easy to reach a state of desynchronization where the state stops being replicated and position/rotation of cars mismatch. As an ...

FCableSceneProxy::BuildCableMesh thrashes memory allocator

UE - Simulation - Physics - Feb 12, 2025

FCableSceneProxy::BuildCableMesh in CableComponent.cpp:233 showed up as a hot spot in profiling because the two TArray allocators in SetDynamicData_RenderThread used by BuildCableMesh are created an ...

Mirror operation on Physics Asset produces wrong results for constraints, including flipped axes

UE - Simulation - Physics - Feb 7, 2025

The Physics Asset Editor has a "mirror" feature that allows physics bodies and constraints to be mirrored from one side of a skeleton to the other. If this operation worked correctly, it could save ...

Capsule component renders incorrectly with non-uniform scale

UE - Simulation - Physics - 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 ...

ensure(false) being fired in FGenericParticlePairMidPhase::FindOrCreateConstraint from key collision

UE - Simulation - Physics - Jan 27, 2025

ensure(false) being fired in FGenericParticlePairMidPhase::FindOrCreateConstraint from key collision. The licensee reports one of their users reported this issue and they were able to reproduce a fe ...

Closing a Geometry's Collection Dataflow Editor window when the ChaosVehiclePlugin is enabled is crashing the Unreal Editor when running it with the -stompmalloc flag

UE - Simulation - Physics - Jan 27, 2025

As the title describes, closing a Geometry's Collection Dataflow Editor window when the ChaosVehiclePlugin is enabled is crashing the Unreal Editor when it is running with the -stompmalloc flag. The ...