ChaosCacheManager is not reproducing Trailing Events

UE - Simulation - Physics - Mar 28, 2025

ChaosCacheManager (CCM) is not reproducing Trailing Events. Particles set to track Trailing Events correctly follow the position of the trailing event when the Geometry Collection (GC) is physically ...

Physics constraint component doesn't work when placed inside a child actor, while using world partition and streaming is enabled

UE - Simulation - Physics - Mar 21, 2025

Context: In a World partition level, to reduce complexity and provide a scalable solution when creating new projects, grid cell streaming can be enabled. Problem: The problem is that physics constr ...

Vehicle Template with Thruster Configuration will be affected by force relative to the distance from the origin

UE - Simulation - Physics - Mar 18, 2025

Vehicle Template vehicle with added Thruster Configuration to its VehicleMovementComponent will be affected by force relative to the distance from the origin. At around 200000 the force is enough to ...

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 ...

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 ...

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 ...