Mac - Inconsistent results for Lumen renders

TM - Rendering - Jun 3, 2025

Reported in SF [Link Removed] and [Link Removed] Users on Mac are reporting inconsistent rendering results for Lumen in image exports that do not include any settings changes. When exporting some ...

ChordBlockers don't work as expected when ChordAction is set in InputAction

UE - Gameplay - Input - Jun 3, 2025

In the Enhanced Input System, when using a UInputTriggerChordAction to define a chorded input (e.g., Shift + W), the automatic chord blocking system (UInputTriggerChordBlocker) only functions correc ...

Collision Drawing in Cooked Builds (Development) doesn't Show Geometry for Nanite Meshes

UE - Graphics Features - Jun 2, 2025

Context The showFlag.CollisionVisibility 1 cvar is a viewport visualization mode that highlights which Actors will block visibility. The showFlag.CollisionPawn 1 cvar is a Player Collision viewmode ...

Local lights appear broken when baking lighting with GPU Lightmass

UE - Graphics Features - Jun 2, 2025

Encountered an issue where local lights appear to be broken when baking lighting with GPU Lightmass. See screenshots attached. Tested regression in //UE5/Release-5.5 @ CL40574608 and the issue does ...

Possible bug with GAOGlobalDistanceFieldCacheMostlyStaticSeparately

UE - Graphics Features - Jun 2, 2025

The Global Distance Field can constantly update, even when the camera is stationary, in large World Partition maps. This bug requires a large amount of the World Partition map to be loaded to reprod ...

Virtual Bone caused nanite skinned mesh crash

UE - Graphics Features - Nanite - May 31, 2025

When a Nanite skeletal mesh has a virtual bone the engine can crash when changing LODs ...

StructUtils plugin's `FInstancedStruct` in a CPP-defined struct in a `TArray` on an actor component defined in CPP and implemented in BP. Populating the instanced struct in an actor BP's class defaults breaks serialization of the class defaults.

UE - AI - May 30, 2025

Context Instanced structs are great for holding simple data with the main advantage they have is a low memory overhead unlike instanced objects. Problem The problem is in StructUtils plugin's `FIns ...

[5.4+] World Partition Landscape Spline Meshes Builder - Source landscape splines are not properly removed/hidden

UE - World Creation - Worldbuilding Tools - HLOD - May 30, 2025

LandscapeSplineActors and LandscapeSplineMeshesActors are not behaving as expected in 5.4 or 5.5. Testing in 5.4 the issue mostly seems to stem from issues with the Target Landscape -> Landscape Ac ...

Crash in UPCGComponent::CleanupLocalImmediate(bool,bool) on file load

TM - Tools - May 30, 2025

Reported in SF [Link Removed] User has a file that will crash at launch consistently. Crash report indicates the problem is with PCG content inside the file. ...

Multiple setter functions in UMaterialEditingLibrary always return false even when the parameter is correctly set on the MaterialInstance.

UE - Rendering Architecture - Materials - May 30, 2025

In Unreal Engine, materials can expose parameters that can then be modified via instances (MaterialInstanceConstant). The UMaterialEditingLibrary provides several functions to modify these parameter ...