Unreal Engine Issues

Landscape.Nanite.MaxSimultaneousMultithreadBuilds hangs indefinitely

It's possible for NaniteStaticMeshesInFlight to never be decremented because all the background workers are waiting indefinitely for the ones in flight to complete their static mesh build.  ...

Landscape Transparent with r.Lumen.DiffuseIndirect.Allow 0

Disabling Disregard for GC with an invalid asset in GameplayTagTableList causes a controlled crash

Disabling Disregard for GC leads to a crash in GarbageCollectionVerification.cpp VerifyObjectFlags. This crash occurs when there is an invalid path specified in GameplayTagTableList. The cause of t ...

FILTER_COMMANDLINE_LOGGING cannot be used without forcing UE_COMMAND_LINE_USES_ALLOW_LIST

There's two ways to affect the commandline in CommandLine.cpp: FILTER_COMMANDLINE_LOGGING - for filtering certain or all args (if left empty) from the log. UE_COMMAND_LINE_USES_ALLOW_LIST - for on ...

HideBoneByName translates bone to parent which breaks skinning

Calling HideBoneByName on a bone causes that bone (and all it's children) to be translated to the parent bone's location.  This code in UpdateRefToLocalMatricesInner is responsible: bool bNeedToHid ...

'Platform Stats' incorrectly display the number of Texture Calls for a material

When the DBuffer is disabled in the project settings, the Material Editor Stat page will still display the estimated texture lookups for the DBuffer. It appears that the code that adds these estimat ...

Memory leak when Lumen is disabled but r.MeshCardRepresentation=1

When Lumen is disabled, but the cvar "r.MeshCardRepresentation" is set to 1, Lumen will continuously enqueue object removal from the Lumen Scene, without ever emptying the array of primitives to rem ...

Cook Determinism - Construction Scripts and ChildActorComponent issues with DiffCooks

To step through the issue, in the -DiffOnly cook add a breakpoint to UChildActorComponent::OnRegister and UChildActorComponent::OnUnregister. It should hit 4 times:Once when LoadPackage loads the ma ...

Chaos Cache : When Min Speed To Spawn Trailing Particles > 0, particles are never spawned by chaos cache trailing events

Because UniagaradataInterfaceChaosDestruction::HandleTrailingEvents does not respect incoming TrailingEvent data, the debris velocity during chaos cache playback is always evaluated as zero. The fo ...

Removal of ReplacementSceneComponent leaves trashed components during WorldPartitionResaveActorsBuilder

Running WorldPartitionResaveActors builder can detach attached actors. ...