The pak file specified in PakFileRules is not created correctly

UE - CoreTech - Aug 8, 2023

The rules by which chunks are created are ambiguous and currently do not ensure that both PakFileRules and PrimaryAssetLabel settings are reflected. In this sample, depending on the PrimaryAssetLabe ...

"Used with Particle Sprites" prevents material instances thumbnails from being editable

UE - Rendering Architecture - Materials - Aug 4, 2023

The thumbnails helpers will force material instances to be a plane, if their parent material is unedited. This can be worked around by editing the parent material, but editing the material instance ...

BoneList and BoneFilterActionOption in LOD0 of LODSettings are displayed after editing other LOD level

UE - Anim - Runtime - Jul 31, 2023

BoneList and BoneFilterActionOption in LOD0 of LODSettings are filters by the following code. void FSkeletalMeshLODSettingsDetails::CustomizeDetails(IDetailLayoutBuilder& LayoutBuilder) { ... st ...

Logging out and then logging in as a new user results in slate creating multiple Slate User IDs

UE - Gameplay - Input - Jul 28, 2023

I believe this is happening because when you change your logged in user, the Slate Application will automatically create a new second slate user with an ID of 2. This is bad because the Slate App is ...

Inaccurate motion vectors when using different position binding in renderer

UE - Niagara - Rendering - Jul 27, 2023

Even though the particles are not moving, and the velocity is zero, the output motion vectors are non-zero. This seems to only happen if using two sources of particle positions.  ...

BP property initialization fast path does not handle non-instanced properties assigned to default subobjects correctly

UE - Framework - Blueprint - Jul 27, 2023

Non-instanced object ref properties are incorrectly being skipped at property initialization time when Blueprint class instances are spawned with the fast property initialization path enabled. This ...

NiagaraComponent attached to the character won't stay active when travelling to a new level using seamless travel

UE - Niagara - Jul 27, 2023

The pawn character is added to APlayerController::GetSeamlessTravelActorList, so it'll be persisted during server travel. The Niagara component is spawned during BeginPlay and activated manually. W ...

WorldPartitionRenameDuplicateBuilder rename breaks soft object refs

UE - World Creation - Worldbuilding Tools - World Partition - Jul 26, 2023

Renaming map using builder will break soft obj refs and warnings will also appear in the log: Warning: Serialized Class /Script/Engine.World for a property of Class /Script/Engine.Actor. Reference ...

Virtual Heightfield Mesh crash using released Vertex Factory

UE - Rendering Architecture - Jul 25, 2023

When using VirtualHeightfieldMesh we see intermittent crashes in FDepthPassMeshProcessor::TryAddMeshBatch(). This can happen when FVirtualTextureProducerCollection::CallPendingCallbacks() is called ...