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 ...

Replicating a non-root component with simulate physics enabled causes the component to be in the wrong place on spawn, on clients.

UE - Simulation - Physics - Jan 20, 2025

When a BP spawns another, if the spawned Actor has a non-root child component that is simulating physics, on clients, immediately after spawn, the child component will have the world position double ...

A Simulating Physics component with StartAwake = false will be awoken by a Welded component

UE - Simulation - Physics - Jan 10, 2025

A Simulating Physics component with StartAwake = false will be awoken by a Welded component If a welding occurs during the call to OnCreatePhysicsState, this breaks the start awake disabled flag. Th ...

Unnatural de-overlap occurs when moving inside a mesh-type collision located far from the origin

UE - Simulation - Physics - Jan 8, 2025

The problem appears to occur when the distance from an edge is mixed with positive and negative values in VectorEPA function. The following workaround is suggested that uses absolute values of dista ...

Enabling "ShowFlag.PhysicalMaterialMasks" causes editor crash when physical material masks aren't yet imported.

UE - Simulation - Physics - Dec 3, 2024

When there is a physical material mask asset that has been created and applied to a mesh in the level without having a texture source imported yet, and then "ShowFlag.PhysicalMaterialMasks" is enabl ...

Physical Material Mask bug found in GetPhysMatIndex, potentially causing issues with lookup.

UE - Simulation - Physics - Dec 2, 2024

On line 408 of UPhysicalMaterialMask::GetPhysMatIndex() in PhysicalMaterialMask.cpp, the AdjustCoord() function is given AddressX for both the U and V coordinates. The AddressY input is never used i ...

GeometryCollectionActor SetSimulatePhysics false does not stop Physics Simulation

UE - Simulation - Physics - Nov 28, 2024

If the GeometryCollectionActor (GCA) is simulating physics, calling SetSimulatePhysics(false) does not stop the simulation. If the simulation is paused, calling SetSimulatePhysics(true) does as expe ...

The ChaosCacheManager changes the bSimulatePhysics flag from the ObservedComponents and, if deleted, the change will persist, what can lead to confusion as observed physical entities will inadvertently stop simulating physics

UE - Simulation - Physics - Nov 26, 2024

The ChaosCacheManager (CCM) changes the bSimulatePhysics flag from the ObservedComponents and, if deleted, the change will persist, what can lead to confusion as observed physical entities will inad ...

A welded hierarchy blocks updates to collision settings on all but the root primitive. Calling SetCollisionResponseToChannel on the children won't work.

UE - Simulation - Physics - Nov 22, 2024

A welded hierarchy blocks updates to collision settings on all but the root primitive. Calling SetCollisionResponseToChannel on the children won't work. The licensee noticed that IPhysicsProxyBase* ...

Calling BodyInstance.UpdateBodyScale displays erratic behaviors and does not update the rendering scale

UE - Simulation - Physics - Nov 22, 2024

Calling BodyInstance.UpdateBodyScale displays erratic behaviors and does not update the rendering scale. The licensee has reported and presented a repro project that displays the erratic behavior of ...