Memory leak when rendering some meshes with ray tracing enabled

UE - Graphics Features - Jul 19, 2021

This memory leak seems to be caused by the TMemStackAllocator of FRayTracingMeshCommandOneFrameArray. Using the FDefaultAllocator for FRayTracingMeshCommandOneFrameArray works as a workaround. // ...

Creating a Packed Level Instance from an asset with a negative Scale Transform inverts normals

UE - World Creation - Worldbuilding Tools - Level Instances - May 11, 2022

Creating a Packed Level Instance from an asset with a negative Scale Transform inverts normals. Using Create Level Instance will not cause this to occur. ...

[Audio Import] - Cue Points are stripped on import on 24-bit wave files

UE - Audio - Jul 12, 2022

When importing wav files with a higher bit depth than 16, any cue points on the file are stripped.  ...

GeometryCollection clustered by ClusteredGroupIndex does not respect child's gravity setup

UE - Simulation - Physics - Mar 7, 2024

Following code works as a workaround void FClusterUnionManager::HandleAddOperation(FClusterUnionIndex ClusterIndex, const TArray<FPBDRigidParticleHandle*>& Particles, bool bReleaseClustersFirst) ...

Blueprint Add Custom Event unable to resolve delegate signature inside a split struct

UE - Gameplay - Blueprint - Apr 19, 2024

This issue occurs when a static function is created and has a struct parameter that has a delegate exposed to blueprint. When using the helper function in blueprint after having used "Split Struct ...

Missing display units initialization from project settings

UE - Editor - Workflow Systems - Jun 11, 2024

From customer: Hi there, I stumbled upon a bug where the display units as set in the Project Settings under the Editor Appearance category for properties were not getting displayed properly and was ...

Material Emissive Color not working with SkyAtmosphereIlluminance Material Expression

UE - Graphics Features - Jan 9, 2025

A licensee has reported that they are unable to use an emissive material utilizing the SkyAtmosphereLightIlluminance material expression together with Nanite and Lumen. The linked UDN has some more ...

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 ...