FScopedEditorWorld doesn't clean up old world when going out of scope

UE - World Creation - Worldbuilding Tools - World Partition - Jan 19, 2024

In a commandlet, when FScopedEditorWorld exits, it leaves references behind and prevents garbage collection of the PersistentLevel and non-spatial actors. This leads to an issue when a second FScop ...

Map actor reconstruction does not reattach external non-root components

UE - Gameplay - Components - Jan 17, 2024

For two map placed actors, if one actor B's non root component is attached to another actor A, the attachment is not retained when actor A reruns its construction script, such as when moving actor A ...

Pre-UE5 serialized FVariant FVector data corruption when deserialized in UE5

UE - Gameplay - LWC - Jan 15, 2024

FVariant is a struct that implements a union of data types, including FVector. When assigning an FVariant an FVector value in engine versions UE 4.27 or earlier, the FVariant will deserialize incorr ...

Double clicking on Interface Function in Blueprint Graph does not take you to the function implementation.

UE - Editor - Jan 11, 2024

When double-clicking on an interface function call within a blueprint, the expected behaviour is that it will take you to the implementation of this function. However, it currently does nothing. ...

Specular/Anisotropy problems with Nanite Meshes

UE - Rendering Architecture - Jan 11, 2024

Specular highlights can disappear with clearcoat materials, when "Clear Coat Enable Second Normal" is enabled ("r.ClearCoatNormal"). ...

Setting GDelayTrimMemoryDuringMapLoadMode = 2 causes crash on same map reload

UE - Gameplay - Jan 8, 2024

GDelayTrimMemoryDuringMapLoadMode is a CVar that controls whether a garbage collection should take place during map change after unloading the previous map and before loading the new one. By default ...

Gameplay Ability Component Montage Replication incorrectly handles cyclic animation sections

UE - Gameplay - Gameplay Ability System - Dec 4, 2023

In AbilitySystemComponent_Abilities.cpp, the check for the client being on a different section on line 3059 checks that the RepNextSectionID is not the current section. One would assume this is beca ...

Single sided complex collision mesh collision blocks character movement from backside

UE - Simulation - Physics - Query - Nov 17, 2023

Commenting out the branch in FTriangleMeshSweepVisitor::VisitSweep is a work-around.if (CullsBackFaceSweepsCode != 0) { if (VectorMaskBits(IsBackFace)) { // Don't cull the back face ...

In-editor hitch when deleting one actor in a world with many loaded actors

UE - Foundation - Core - Nov 17, 2023

When editing a level with many actors (1000+), deleting an actor results in a noticeable hitch: the editor becomes unresponsive for seconds. This hitch becomes longer the more actors are loaded and ...

Renaming a Blueprint interface asset doesn't update the ImplementedInterfaces list in the Blueprint editor's Class Settings tab

UE - Gameplay - Blueprint Editor - Nov 13, 2023

There is no UI refresh for the Implemented Interfaces list in the Blueprint editor UI after a Blueprint Interface asset is renamed in the Content Drawer. Consequently, the interface cannot be remove ...