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

UE - World Creation - Worldbuilding Tools - 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 ...

Lightmap UV generated on Windows and Mac is not deterministic

UE - Graphics Tools - Modeling Tools - Aug 7, 2024

Screen Probes and Specular Firefly Flickering near screen edges

UE - Graphics 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 ...

Pasting custom data floats from a text editor into a instanced static mesh component crashes the editor

UE - Framework - Components - Aug 5, 2024

When an instanced static mesh component with a material using a PerInstanceCustomData node has its data floats pasted in, the editor crashes with an "Array index out of bounds" error. The licensee w ...

Issue with Landscape Layer Blending Node compile in UE 5.4.2

UE - Graphics Tools - Terrain - Aug 2, 2024

When the SetMaterialAttributes Material Expression is used without an input to MaterialAttributes, it will cause Landscape Layer Blend expressions to fail to compile if it is the only layer on a par ...

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

UE - Graphics Features - Lumen - Jul 29, 2024

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 ...

In UE 5.4, some config variables are not getting saved correctly, due to the new User/Editor rules.

UE - Simulation - Visual - Jul 24, 2024

A lot of properties are not getting saved correctly to custom configuration files. This looks like that it can be cause by the FConfigContext::PerformLoad function. New conditionals have been added ...

Reflection Captures permanently unload with world streaming

UE - Graphics Features - Jul 19, 2024

When a reflection capture is unloaded due to streaming, it cannot be reloaded when the player returns to that area in the world because FReflectionCaptureData::OnDataUploadedToGPUFinal deletes the C ...