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 ...

A Skeletal Mesh simulating physics that hits a Geometry Collection Actor with OneWayInteraction true, OneWayInteractionLevel 1, and is using Damage Propagation (default) will be accelerated so fast it immediately disappears by hitting the world limits

UE - Simulation - Physics - Destruction - Jan 20, 2025

A Skeletal Mesh simulating physics that hits a Geometry Collection Actor with OneWayInteraction true, OneWayInteractionLevel 1, and is using Damage Propagation (default) will be accelerated so fast ...

Navigation: Exiting game while async nav building tasks are running can cause null pointer access of OctreeController.NavOctree from worker thread

UE - AI - Navigation - Jan 14, 2025

Context Projects can turn on the project setting bDoFullyAsyncNavDataGathering to execute navigation mesh building tasks on worker threads. Some of these tasks will access the NavOctree, whose life ...

Params in material instance disappear when grouping is changed in material with a material layer

UE - Rendering Architecture - Materials - Jan 11, 2025

If there is a texture parameter within a specific material attribute stream in the base material and also within the base material layer, they must have the same parameter group otherwise the parame ...

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 ...

Can't get accurate Anim Notify State elapsed duration while in a montage.

UE - Anim - Gameplay - Dec 13, 2024

When GetCurrentAnimationNotifyStateTimeRatio is used inside of a montage it can return the wrong time ratio in certain cases. ...

Swapping the C++ Root Component from a Child BP class, pressing Save, Compile, but not Saving afterwards, will leave the Root Component in a locked state, meaning the it cannot be viewed or edited in the Details Panel after an Editor restart

UE - Gameplay - Blueprint - Dec 9, 2024

Swapping the C++ Root Component from a Child BP class, pressing Save, Compile, but not Saving afterwards, will leave the Root Component in a locked state, meaning the it cannot be viewed or edited i ...

Issue with PLA Editing inside another PLA causes Z-Fighting or Mesh Disappearance.

UE - World Creation - Worldbuilding Tools - Dec 6, 2024

When editing a Packed Level Actor (PLA) that is inside another PLA, z-fighting or mesh disappearance will occur. More specifically, it is seen when duplicating a mesh inside the PLA, upon saving the P ...

Duplicated TextureLoadVirtualPageTable in GetCustomData functions in generated HLSL add to the total instruction count due to TextureLoad having side effects

UE - Rendering Architecture - Materials - Dec 4, 2024

When using materials with CustomData inputs, such as the Eye material with Iris Distance and Mask, Virtual Texture samples will increase the instruction count for each unique VTPageResult. Each cus ...

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 ...