LODs with screen size 0 in legacy assets are incorrectly converted to 1 on load

UE - Graphics Features - Sep 11, 2025

When loading a mesh asset (static or skeletal) created in an old version of Unreal (e.g. 4.10), any LOD whose LOD screen size was originally set to 0, is converted to 1. This causes LODs that would ...

Incorrect resolution used because SetProcessDpiAware() is not called when bAllowHighDPIInGameMode=False

UE - Rendering Architecture - Aug 8, 2025

The incorrect resolution is used on computers with 4k monitors that use DPI scaling (default 150%) because the default for UE projects is bAllowHighDPIInGameMode=False which results in SetProcessDp ...

GPU Crash from out of memory read/writes in Lumen when using non-power-of-2 TracingOctahedronResolution

UE - Graphics Features - Lumen - Aug 6, 2025

When the r.Lumen.ScreenProbeGather.TracingOctahedronResolution is not a power of 2 or LumenFinalGatherQuality in a Post Processing Volume is set to a value such that the TracingOctahedronResolution ...

Sequencer - When a subsection has negative play rate, any nested sub-subsections fail to evaluate

UE - Anim - Sequencer - Jul 3, 2025

Consider a sequence hierarchy with more than two layers. If the top-level sequence uses a negative timescale on a sub-sequence, the contents inside it animate as expected, but any nested sub-sequenc ...

Sphere Mask ArgInvHardness missing multiplication

UE - Rendering Architecture - Materials - Jun 27, 2025

Hi Epic, In MaterialExpressions.cpp UMaterialExpressionSphereMask::Compile(), hardness is not calculated the same way in both <if> conditions. One is missing a multiplication by 0.01f. Specificall ...

Instanced Static Meshes ignore max World Position Offset Displacement for bounds after UpdateInstanceTransform is called

UE - Graphics Features - Jun 18, 2025

When an Instanced Static Mesh Component (ISMC) uses a material with a non-zero Max World Position Offset Displacement, the bounds are correctly expanded at initialization. However, after calling Upd ...

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 ...

bIgnoreAllPressedKeysUntilReleaseOnRebuild in Enhanced Input behaves unexpectedly during pawn possession

UE - Gameplay - Input - Jun 11, 2025

This is a speculative bug report from the user.  The fix for this is to re-do the work of 31224705 but in a better way. The "bShouldBeIgnored" flag is being overriden by the previous mapping's va ...

Interchange Runtime .glb Import Crash When Packaged

UE - Editor - Content Pipeline - Import and Export - Jun 10, 2025

The runtime import process works fine in editor, but fatal error when trying to do so with packaged build of project. My function that calls ImportAsset():bool UMeshLoader::RequestMeshLoad(FString ...