Material slot assignment incorrect after mesh reduction completely removes all triangles from a section

When mesh reduction results in a section becoming empty, the material slots are incorrectly assigned. e.g. if section 0 gets removed due to it having no triangles after reduction, then its material ...

Editor-only blueprints like WidgetBlueprint are not added to cooked asset registry class hierarchy

UE - Core - Systems - Aug 10, 2022

Both the Asset Registry and Asset Manager look for all subclasses of UBlueprintCore and use that to search for blueprint classes and construct an inheritance hierarchy. This always works in editor b ...

TMap does not rehash when the property change if the key is struct

UE - Editor - Verse Class Editor - Feb 17, 2023

If TMap's Key is a unique Struct, TMap's rehash will not run even if elements are added or changed in DetailPanel such as DataAsset. So TMaps's Find etc. will fail This issue is very similar to ...

Crash sometimes occurs when enabling the Gravity tool on part of a Sketchfab object.

TM - Tools - May 4, 2024

Current state Triggering Gravity on element from Sketchfab object's tree, may result in crash. For 100% reproduction rate, download 'Rank 3 Police Unit' object and apply Gravity to its element 'Rank ...

Engine Crashes When Trying To Reimport Skeletal Mesh For One That Has No Clothing Data

UE - Simulation - Physics - Character - Jan 17, 2020

The engine crashes when trying to reimport a skeletal mesh that has no clothing data. This seems related to https://jira.it.epicgames.net/browse/UE-86948. Found in 4.24.1 CL#10757647 Reproduced in ...

Indirect lighting cache generates points inside interpenetrating static meshes

UE - Graphics Features - Jun 10, 2015

Seems to be an issue with the indirect lighting cache where if you have interpenetrating static meshes (for example static mesh rocks that make up the ground), there are cases where the cache points ...

Distance calculation using World Position are rendering incorrectly when packaged or launched for iOS and Android

UE - Platform - Mobile - Jan 15, 2016

When using a calculating the distance between the Absolute World Position (Including Material offsets) and a set Vector value, the correct value appears rendering to a texture's UV in PC Mobile Prev ...

Real-time thumbnails causing large performance issues

UE - Graphics Features - Feb 1, 2017

When Real-Time Thumbnails are enabled in the content browser and you have many blueprints with static meshes (or anything that is rendered in the blueprint's viewport), the real-time tooltips cause ...

Crash on Mac when adding Convex Collision to a mesh converted from a brush

UE - Platform - Apple - Jun 6, 2017

This is one of the top Mac crashes occurring in 4.16. Caused by adding Auto Convex Collision to a mesh converted from a brush. Does not occur on Windows. User DescriptionsI was trying to add a conv ...

[CrashReport] ULevel::GetWorldSettings() - UMaterialInstanceThumbnailRenderer::Draw

Tools - Aug 29, 2017

This is a common assertion that has occurred since at least 4.14 and affected nearly 100 users. The callstack is similar to [Link Removed], which was marked fixed for 4.14. User DescriptionsUndoi ...