Deleting transient actor marks level dirty

UE - World Creation - Worldbuilding Tools - Feb 6, 2025

The licensee has noticed that the deletion of a transient actor still marks the scene as dirty and asks it to be saved. Checking the source it was noted that the transient flag is not verified on de ...

COND_InitialOnly property not written to first replay checkpoint after being changed

UE - Networking - Feb 5, 2025

When recording a checkpoint, it is treated as an initial replication, as all the changed properties since the channel was opened need to be recorded. This normally results in any initial only proper ...

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 ...

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 ...

HLODs appear dark/near black when built for very large geometry with Virtual Textures enabled

UE - World Creation - Worldbuilding Tools - HLOD - Jan 27, 2025

Building HLODs for a very large landscape with Virtual Textures enabled results in the built HLODs being very dark for the most part. Building the same large landscape's HLODs with Virtual Textures ...

In -game in Editor, if streaming-in a LevelInstance and initialize its world partition, then leaving that cell and make it go outside the streaming grid, to re-enter it again, will trigger a check(!StreamingPolicy) if no GC has happened during that time.

UE - World Creation - Worldbuilding Tools - World Partition - Jan 27, 2025

This crash can be fixed by adding a couple of || IsRunningGame() like it is done here:    FGenerateStreamingContext Context = FGenerateStreamingContext()        .SetLevelPackagesToGenerate((bIsPIE ...

Disabling bLerpUVs in Nanite Settings of Static Mesh causes texture warping in clusters

UE - Graphics Features - Nanite - Jan 21, 2025

The licensee has identified a potential fix by changing if( Settings.bLerpUVs ) to if( Settings.bLerpUVs || UVIndex == 0 ) On line 389 of NaniteBuilder\Private\Cluster.cpp in UE 5.5 ...

A Skeletal Mesh simulating physics that hits a Geometry Collection Actor with OneWayInteraction true, OneWayInteractionLevel 1, and is using Damage Propagation (default) will be accelerated so fast it immediately disappears by hitting the world limits

UE - Simulation - Physics - Destruction - Jan 20, 2025

A Skeletal Mesh simulating physics that hits a Geometry Collection Actor with OneWayInteraction true, OneWayInteractionLevel 1, and is using Damage Propagation (default) will be accelerated so fast ...

Undoing Replace Actor on Level Instances do not reload the Level Instance

UE - World Creation - Worldbuilding Tools - Level Instances - Jan 14, 2025

Undoing Replace Actor on a Level Instance does not properly reload the previous Level Instance. ...

Params in material instance disappear when grouping is changed in material with a material layer

UE - Rendering Architecture - Materials - Jan 11, 2025

If there is a texture parameter within a specific material attribute stream in the base material and also within the base material layer, they must have the same parameter group otherwise the parame ...