Fixup of spawnables from 5.4 to 5.5 loses custom track names

UE - Anim - Sequencer - Feb 5, 2025

In the process of upgrading from 5.4 to 5.5. One of our systems relies on the internal track names in the sequence to dynamically find an actor to bind the track to. As I was testing the system in ...

Translucent materials in the PostMotionBlur pass can cause a flickering viewport artefact when using TAA

UE - Graphics Features - Feb 5, 2025

There appears to be a bug relating to rendering multiple windows that can trigger under unknown circumstances. It has been reported on rectangle lights in the forums and on PostMotionBlur materials ...

Static Meshes that are reimported with less materials can lead to map check errors on instances that had overriden materials that require manual cleanup

UE - Rendering Architecture - Feb 5, 2025

StaticMeshActors placed in the world can override the default materials of a static mesh. If the static mesh is then reimported with less materials, the actors maintain references to unused material ...

Editor/Game Ensure hit with RayTracing enabled on AMD GPU

UE - Graphics Features - Ray Tracing - Feb 4, 2025

A Static Mesh asset will trigger an ensure when generating building the ray tracing acceleration structure on AMD GPUs. ...

SDF/Mesh Cards do not follow material settings applied on static meshes.

TM - Core - Feb 4, 2025

Building SDF and Mesh Cards require material properties (2 sided and blend mode) applied on Static Mesh to be known at Static Mesh build time. If not, it may leads to rendering artifacts: Reflectio ...

Each bone scales are improperly applied in the physical animation

UE - Simulation - Physics - Character - Feb 4, 2025

Suggested fix from licensee is : PhysAnim.cpp@339 #if 0 FVector RelPos = RecipScale3D * RelTM.GetLocation(); #else FVector RelPos = (BoneIndex == 0) ? RecipScale3D * RelTM.GetLocation() : Rec ...

FLevelInstanceActorGuid::GetGuid issue in Multiplayer

UE - World Creation - Worldbuilding Tools - Level Instances - Feb 3, 2025

I am doing some runtime manipulation of data layers and I am running into a check failure due to a zero guid in FLevelInstanceActorGuid::GetGuid during multiplayer testing. When I debug FLevelInsta ...

Spline mesh crashing in FRayTracingDynamicGeometryCollection::AddDynamicMeshBatchForGeometryUpdate

UE - Graphics Features - Ray Tracing - Jan 31, 2025

A crash occurs when using ray tracing with spline meshes preceded by the following ensure : Ensure condition failed: NumCPUVertices <= VertexBufferNumElements  File: Engine\Source\Runtime\Renderer\ ...

Building Geometry Stops UTickableWorldSubsystem Ticking

UE - Gameplay - Jan 31, 2025

Can be mitigated by reopening the Level. There is a repro project provided by the licensee on the case ticket. ...