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 ...

Incorrect mesh deformation when Max World Position Offset Displacement used

UE - Graphics Features - Nanite - Feb 12, 2025

When Vertex Animated Texture is used to animate a mesh with World Position Offset, often the Max World Position Offset Displacement Material setting must be increased or the Bounds Scale increased, ...

DMX component in world partitioned level fails cook

UE - Virtual Production - IO - DMX - Feb 10, 2025

Since UE5.5, RegisterComponent has been called during cook process, So unnecessarily references from DMXLibrary to DMXComponent has been added.  There is a workaround to avoid adding references : ...

[AI] Navigation System can be constructed in situations where the NavigationObjectRepository subsystem is not valid

UE - AI - Navigation - Feb 7, 2025

Investigate and fix all calls where the Navigation System is constructed without the NavigationObjectRepository subsystem being valid.  ...

[AI] "LogNavigation: Warning: UNavigationObjectRepository is required for navigation system operations" when cooking a project with validation enabled

UE - AI - Navigation - Feb 7, 2025

The cook completes with a warning for "LogNavigation: Warning: UNavigationObjectRepository is required for navigation system operations" which causes many CI pipelines to fail as they use treat warn ...

[Interchange] Crash on asset re-import

UE - Editor - Content Pipeline - Import and Export - Feb 7, 2025

We've started seeing a crash in editor when re-importing one of our assets. <pre class="ql-syntax">Assertion failed: (Index >= 0) & (Index < ArrayNum) [Link Removed] [Line: 783] Array index out of ...

[AI] Navmesh tiles on different layers get removed while streaming out in WP Dynamic Modifiers Only navmesh

UE - AI - Navigation - Feb 6, 2025

 Streaming out the navmesh and streaming the area back into the world before the GC runs causes the navmesh streamed back into the world to only have navmesh tiles on a layer with tiles that would b ...

[Interchange][FBX] Import model with custom collision prevents socket to be imported

UE - Editor - Content Pipeline - Import and Export - Feb 5, 2025

I would like parity with legacy: 1) only one material 2) socket to be imported Box_Socket file imports same in legacy and interchange: it is just box and socket without collision. ...

An ensure is triggered when a StaticMesh is set inside a StaticMeshComponent on an actor, and another actor references the static mesh actor from two child actor components.

UE - Content - Engine - Feb 5, 2025

There is an issue when setting a Static Mesh inside a blueprint that it is referenced by another blueprint with more than one child actor. An ensure is triggered inside the engine, and there is a ...

Mesh particles are inadvertently culled when NiagaraActor scales large

UE - Niagara - Feb 5, 2025

When a large scale value (e.g. 500) is set on the NiagaraActor, the mesh particle is unexpectedly hidden. This may be a side effect of the following change ([Link Removed]). PrimitiveData.NonUnifo ...