GPULightmass baking issues on AMD

UE - Graphics Features - Jul 28, 2025

Volumetric Light Maps are not generated correctly when baked with GPU Lightmass on AMD GPUs. The issue has been reproduced on RX 9070, RX 9070 XT, and RX 7900 XT. ...

Unloading a World Partition region during nested Level Instance inline editing prevents exiting editing mode

UE - World Creation - Worldbuilding Tools - Level Instances - Jul 28, 2025

In the case of a single-layer Level Instance, actors are still referenced even when the region is unloaded. However, in the case of nested Level Instances, the level being edited is discarded when t ...

Exception generated launching Horde Agent built with 5.6

UE - Foundation - Horde - Server - Jul 28, 2025

The source of the problem seems to be using IOptionsSnapshot with a Singleton. Per the MS documentation for IOptionsSnapshot, "Is registered as Scoped and therefore can't be injected into a Singleto ...

Restoring AnimInstance fails when ControlRig and Motion tracks are consecutive in sequencer

UE - Anim - Anim in Engine - Jul 27, 2025

In the Sequencer, Control Rig and Animation tracks are placed consecutively. During the transition, the Animation track captures the AnimInstance state before the ControlRig track's RestoreState is ...

Merge Actor - Approximate Actors algorithm is using Mesh Description directly rather than the Nanite parameters

UE - World Creation - Worldbuilding Tools - Merge Actor - Jul 25, 2025

In an ideal world, all mesh merge algorithms should have the option to use as input one of the followingRender mesh (non-nanite) (+ the option to target a specific LOD)Mesh Description (+ the option ...

VALIDATE_UNIFORM_BUFFER_LIFETIME fails compilation

UE - Graphics Features - Jul 24, 2025

Also verified on Release-5.5.4 CL 40574608 ...

Nanite Landscapes in Non world partition maps has missing sections

UE - Graphics Tools - Terrain - Landscape - Jul 23, 2025

Nanite in non world partition worlds builds with missing section, almost half the landscape is missing. Looking at the nanite overdraw as attached, it shows an interesting pattern. ...

heterogeneous volumes SkyLight VolScatter Intensity not working

UE - Niagara - Rendering - Jul 23, 2025

Heterogeneous Volumes do not respect the Volumetric Scattering Intensity values when running with Lumen, but do (correctly) when rendering with the Path Tracer. ...

Artifacts appear on translucent particle systems during camera motion blur

UE - Rendering Architecture - Jul 23, 2025

Translucent particle systems exhibit visual artifacts when the camera moves, even though motion vectors are disabled for the particle emitters. While switching the Translucency Pass to "After Motio ...

Custom Primitive Data color widget not applying correctly to static mesh components in Blueprint editor.

UE - Rendering Architecture - Materials - Jul 23, 2025

Context Custom Primitive Data is used to store custom data in an index array that is accessible through Blueprint and code. This allows for variations across instances of the same mesh without needi ...