Adjusting transform of a mesh with LODs causes LODs to flicker

UE - World Creation - Worldbuilding Tools - Foliage - Jun 3, 2015

If a hierarchical instanced static mesh has LODs and is scaled in a blueprint, the mesh will rapidly switch between LODs, causing a flickering effect. Note: This only seems to occur if the camera ...

Calling a child's child in a child blueprint from a spawn actor from class node that is being called back to the child causes an error

UE - Gameplay - Blueprint - Jun 29, 2015

Calling a child's child in a child blueprint from a spawn actor from class node that is being called back to the child causes an error. Basically, when using the spawn actor node referencing the chi ...

Grandchildren of UDataAsset are not properly registered by the Asset Manager

UE - Gameplay - Sep 19, 2017

Any child class of UDataAsset (parent) will properly be picked up when the Asset Manager's Asset Base Class" field is set to the appropriate class. However a grandchild class (Child) with the same ...

ARCore Non-AR Camera inherits AR Camera rotation

UE - Platform - XR - Jul 25, 2018

When transitioning from AR map/pawn to Non-AR map/pawn the direction the phone is facing is applied to Non-AR pawn. Only occurring on Android/ARCore Also tested in Main CL #4229747 Tested with Pi ...

Collision Problems on Meshes with Collision Complexity Setting UseComplexAsSimple

UE - Simulation - Physics - Dec 20, 2018

Collision does not appear to work properly on a static mesh that is set up with UseComplexCollisionAsSimple. ...

Previous Tangent Recalc` and Size by Life misbehave at low FPS

UE - Niagara - Jun 18, 2019

At low FPS particle systems with "Previous Tangent Recalculation" enabled in the Ribbon Data result in messy mesh generation. Found in 4.21 CL# 4753647, 4.22 CL# 6574378, 4.23 CL# 6925347, and 4.24 ...

Unable to save a map file when editing a LevelInstance by placing multiple LevelInstances on a PersistentLevel

UE - World Creation - Worldbuilding Tools - Level Instances - Mar 17, 2023

Can not save the map file, if trying to edit a LevelInstance in a PersistentLevel where multiple LevelInstances are placed. The workaround is to open and edit the LevelInstance as PersistentLevel.  ...

Lumen indirect lighting artifacts when far from world origin

UE - Graphics Features - Lumen - Feb 6, 2024

Lumen seems to not be using Large World Coordinates somewhere. The Lumen Scene develops artifacts at large distances (5000 KM) from the world origin. ...

UV Offset Effect Material in RetainerBox Causes Visual Artifacts in Editor Preview

UE - Editor - UI Systems - UMG - Apr 22, 2025

When a UV Offset is applied in a RetainerBox effect material, visual artifacts appear only in the editor — not at runtime — if a widget with a dotted preview outline (like CanvasPanel) is placed dir ...

20 FPS performance drop between 4.7.6 and 4.8 on devices rendering Metal only

UE - Platform - Mobile - Jun 22, 2015

User reported a considerable performance drop on iOS between versions 4.7.6 and 4.8. I was able to reproduce this perf drop using the steps he provided. ...