It's possible to create a locked state on a rigidbody by creating a TransientField that will keep the rigdbody Sleeping even after it leaves the Field's area of influence

UE - Simulation - Physics - Sep 5, 2024

The licensee found a way to lock the state of a rigidbody as PBDRigid->ObjectState() == EObjectStateType::Sleeping by subjecting it to a particular transient field composed of a RadialFalloff and a ...

Physics Linear Velocity functions from UPrimitiveComponent always return (0,0,0) velocity

UE - Simulation - Physics - Jul 30, 2024

In Unreal Engine version 5.4, all Physics Linear Velocity functions inside PrimitiveComponent class are returning always a velocity of (0,0,0), even if the Body Instances are moving. This was workin ...

In UE 5.4, some config variables are not getting saved correctly, due to the new User/Editor rules.

UE - Simulation - Physics - Jul 24, 2024

A lot of properties are not getting saved correctly to custom configuration files. This looks like that it can be cause by the FConfigContext::PerformLoad function. New conditionals have been added ...

Geometry Collections don't support any collision visualization modes (Collision, CollisionVisibility or CollisionPawn)

UE - Simulation - Physics - Jun 27, 2024

Geometry collection objects do not display any collision visualization, either collision color or wireframe overlay when the view mode is set to Player Collision or Collision Visibility or when the ...

City Sample vehicle does not always produce an EndOverlap Event

UE - Simulation - Physics - Apr 23, 2024

Reported on UDN: Something in the setup of the City Sample vehicles means that if a vehicle starts inside a  Box Collider Component then it won't generate an EndOverlap when exiting. Vehicles in ge ...

Clustering GeometryCollections in sleep state forces them to awake

UE - Simulation - Physics - Mar 27, 2024

The sleep state will be overwritten in ClusterUnionManager::UpdateAllClusterUnionProperties. Clustering using AClusterUnionActor results the same behavior as well. ...

The AABBTree spatial acceleration structure goes off-sync when physics substepping is enabled in a "low" framerate environment.

UE - Simulation - Physics - Mar 15, 2024

When you enable the physics substepping, if you run the console command p.Chaos.Solver.DebugDrawSpatialAccelerationStructure 1, you can see how does not follow the physical object. The user that rep ...

GeometryCollection clustered by ClusteredGroupIndex does not respect child's gravity setup

UE - Simulation - Physics - Mar 7, 2024

Following code works as a workaround void FClusterUnionManager::HandleAddOperation(FClusterUnionIndex ClusterIndex, const TArray<FPBDRigidParticleHandle*>& Particles, bool bReleaseClustersFirst) ...

Nanite enabled Geometry Collection is not simulated by ChaosCache in package application

UE - Simulation - Physics - Feb 19, 2024

When using ChaosCacheManager to simulate destruction of a GeometryCollection, destruction is not simulated when Nanite is ON for the GeometryCollection. In the editor, destruction is simulated rega ...

Request to ensure all setup parameters have units described in tooltips

UE - Simulation - Physics - Jan 22, 2024

UDN customer requests that all parameters have units in their tooltips. Need to do a sweep and check what might be missing. This is not a regression, the information will have never been their in t ...