Incremental GC vs Loading Screens deadlock

UE - Core - Systems - Sep 5, 2024

A licensee is reporting that using a loading screen with the incremental garbage collector can result in a dead lock when a loading screen is displayed. The licensee found out that:  -------------- ...

Does FSlateElementBatcher::AddCachedElements need to check if r.HDR.UI.CompositeMode is enabled?

UE - AI Workflows - UI Systems - Aug 28, 2024

When a specific configuration of HDR cvars are set, PIE in a New Editor Window will not render the game world. Settings (For DefaultEngine.ini): ```[SystemSettings] r.AllowHDR=1 r.HDR.Display.Color ...

"Assertion failed: CellIndex < CellIndexMax" when there are a lot of HISM foliage in a level

UE - Engine Scaling - Streaming - Foliage - Aug 19, 2024

Users have come across an issue in 5.4 that causes an assert when many foliage or HISM objects are placed in a level due to a cell size limit. ...

Using Fracture/Chaos Destruction with TSR as Anti-Aliasing Method generates smeared images.

UE - Runtime - Deformable - Aug 15, 2024

Using Fracture/Chaos Destruction with TSR as Anti-Aliasing Method generates smeared images whenever the debris are moving. The client pointed out that the issue might come from GeometryCollectionCom ...

Level Instances appear at the origin on Linux cooks

UE - Engine Scaling - Streaming - Level Instances - Aug 14, 2024

Level Instances are spawned in the origin (0,0,0) after making a packaged build in Linux ...

When level instance is in standalone mode, the actor with IsMainWorldOnly enabled is loaded into persistent level.

UE - Engine Scaling - Streaming - Level Instances - Aug 14, 2024

The IsMainWorldOnly setting for Actor in LevelInstance is not reflected when LevelInstance is in Standalone mode. The setting is respected when LevelInstance is in Embedded mode. The Actor is not l ...

Level Sequences can't reference actors that reside in Level Instances different from the ones they are executed from.

UE - Engine Scaling - Streaming - Level Instances - Aug 10, 2024

Level Sequences can reference many actors, but the references are not solved if the actor is not in the same Level Instance as the one the Level Sequence is being played from, or the root level from ...

MemReport does not seem to respect mesh streaming

UE - Rendering - Architecture - Aug 6, 2024

The function "FStaticMeshLODResources::GetResourceSizeEx(...)" does not take into account that the buffers might be emptied, due to Mesh Streaming. This causes "obj list" to report sizes larger than ...

Screen Probes and Specular Firefly Flickering near screen edges

UE - Rendering - Features - Lumen - Aug 6, 2024

Lumen's rough specular indirect lighting buffer can have fireflies along the bottom and right edges of the screen. Also tested in //UE5/Main, CL: 35177423 ...