Race condition between D3D12 Buffer Defrag and View creation

UE - Rendering Architecture - RHI - Jun 11, 2024

A UDN user reported that the D3D12 resource allocator defragmentation operation races with view creation. View creation needs to be always deferred to the RHI thread. ...

Can't set "r.Shaders.Optimize" to false in UE5.4

UE - Rendering Architecture - Shaders - Jun 7, 2024

The CVar "r.Shaders.Optimize" cannot be set to false from DefaultEngine.ini in the section "[ShaderCompiler]" as its help text describes. Also tested on UE5-Main, CL: 34200103 ...

PostReplicatedChange called for fast array item even when no values change

UE - Networking - Jun 7, 2024

Unless a property is set to REPNOTIFY_Always, we compare the property's received value to the current value on the client before calling the OnRep function. However, when determining if a fast array ...

5.4 Bug - create constraint blueprint node stopped working

UE - Anim - Rigging - Jun 5, 2024

Constraint Actor to Rig with Editor Utility Widget is working for the first time adding to the Sequencer. However if it was deleted and added to Sequencer again, run Scripted Actor Action shows Err ...

Generated world partition maps cause AssetManager warnings

UE - Foundation - Core - Cooker - May 29, 2024

When cooking world partition maps, it automatically writes out several maps in a "Generated" folder below the location of the map in the editor. In the repro above, this will create maps such as /Ga ...

Server will process moves from client with bReplicateMovement set to false

UE - Gameplay - Player Movement - May 28, 2024

UCharacterMovementComponent::ReplicateMoveToServer checks IsReplicatingMovement before sending moves to the server, but the server does not check IsReplicatingMovement when processing these received ...

Actors in always loaded sublevels are not immediately recorded into replays

UE - Networking - May 24, 2024

In FReplayHelper::ReplicateActor, we check Connection->ClientHasInitializedLevel(Actor->GetLevel()) to see if the actor should create a channel or not. However, the DemoNetConnection does not have a ...

LogAssetRegistry Error produces a path error when referring to assets on a junction/hard link/soft link

UE - Foundation - Core - Cooker - May 23, 2024

IAssetRegistry::GetChecked().ScanPathsSynchronous() now eventually calls FPathExistence::LoadExistenceData and logs the errorFPathExistence failed to gather correct capitalization from disk for <p ...

Iris - high latency causes initial hitch for newly spawned actor's movement

UE - Networking - Iris - May 20, 2024

This may possibly be due to FReplicationWriter::CanSendObject waiting for CreateConfirmation. ...

Expanding pins and moving nodes in graph marks Compile as dirty

UE - Anim - Rigging - Control Rig - May 8, 2024

Expanding pins and moving nodes in the graph marks the Control Rig blueprint as dirty, requiring a recompile of the entire blueprint.  Blueprints do not do this.  ...