Arrays in UMaterialEditorInstanceConstant are not updated

UE - Rendering Architecture - Materials - Jun 13, 2025

Any UPROPERTY TArray added to UMaterialEditorInstanceConstant will not cause UI updates when elements are added or removed. This is caused by the custom validator created in FMaterialInstanceEditor ...

Nanite UV switch seams

UE - Graphics Features - Jun 13, 2025

Analytical Derivatives are not calculated properly when using UMaterialExpressionSwitch. Disjoint UVs in screen space result in large jumps in the derivatives, which can cause artifacts as the wrong ...

MRQ - MovieGraphEditorExample.py on_executor_finished_delegate not called in 5.6

UE - Anim - Sequencer - MRQ - Jun 13, 2025

From UDN: We are launching jobs using a modified version of MovieGraphEditorExample.py. In 5.5 everything works fine, but in 5.6 the on_executor_finished_delegate is never getting called when all th ...

Light Mixer - All of the Light Attributes disappear when you have Show Only Selected enabled

UE - Virtual Production - Tools - Jun 13, 2025

All of the Light Attributes disappear when you have Show Only Selected enabled. ...

Fix up GPU breadcrumb labels for Intel performance analysers

UE - Rendering Architecture - RHI - Jun 13, 2025

A licensee has brought up that the GPU breadcrumbs are incorrectly displayed with traces taken on the Intel GPU Analyzer tools (see screenshot). It looks like the format string is being passed on in ...

Dithered LOD transitions sometimes briefly flicker to the next LOD before fading

UE - Graphics Features - Jun 12, 2025

When dithered LOD transitions occur, a brief flash of the next LOD level is first shown on the entire mesh after which the current LOD fades to the next (or previous) LOD. The flashing behavior only ...

Performance hitch from RemoveGeometryCache flushing the render thread

UE - Editor - Content Pipeline - Alembic - Jun 12, 2025

FGeometryCacheStreamingManager::RemoveGeometryCache calls FlushRenderingCommands which shows up as a hitch when profiling. [Link Removed] Ideally the flush added in CL#23782411 to fix a rare deadl ...

StreamableManager does not apply CoreRedirects to loaded paths

UE - Framework - Jun 12, 2025

When loading soft object paths directly, it applies any important CoreRedirects by calling the function FixupCoreRedirects if the initial load attempt fails. In the repro steps, this will apply this ...

Dithered LOD transitions do not work when the camera's field of view changes

UE - Graphics Features - Jun 12, 2025

Dithered LOD transitions do not work when changing the camera's field of view and cause artifacts when both the FOV and camera distance to the object are changed simultaneously. ...

IsLocalController returning incorrect value when PIE listen server travels back to standalone map

UE - Networking - Jun 11, 2025

In this situation where the listen server travels back to a level without listening, IsLocalController can return the incorrect value. After the NetDriver has been shutdown and destroyed, the pawn a ...