Custom node not working with material attributes

UE - Rendering Architecture - Materials - Jul 15, 2024

Using Material Attributes as an input to a Custom Expression causes the HLSL Translator to create multiple CustomExpression# functions, for each used member of the Material Attributes, rather than u ...

High Virtual Texture Sample/Lookup Cost when using a Virtual Texture in a Material Layer Blend

UE - Rendering Architecture - Materials - Mar 14, 2025

Some Material Attribute blends in Material Layer Blends can cause Virtual Texture samples to be duplicated in HLSL. This can be avoided by sampling the Virtual Texture in the Parent Material, and pa ...

Lightmass GI doesn't work with Material-based color changes

UE - Graphics Features - Sep 4, 2015

A licensee is having trouble getting the visual results they want because Lightmass doesn't seem to handle color changes from materials. They are seeing this in 2 cases: (See attached images and tes ...

[CrashReport] Crash while snapping multiple actors at once

Tools - Aug 29, 2017

Crash occurs when selecting all actors and pressing "End" to snap them to the floor. This doesn't occur if you create a blank map and add a few actors to it. The specific conditions may need to be ...

Particle record in the Matinee leads to crash when playing after record.

Tools - Oct 19, 2017

Particle record feature in the matinee seems not properly working in the Editor. When trying to play in the matinee with recorded keys, the Engine will crash with Access violation - code c0000005. ...

Child Actor Component Actor Duplicates and Persists After Play

UE - Gameplay - Sep 26, 2019

When an actor spawns another actor using AddChildActorComponent that comes alphabetically before it based on blueprint name it will spawn an extra actor that will persist when the scene is stopped d ...

Motion vectors not generating correctly in build

UE - Simulation - Physics - Nov 3, 2023

Also tried using “show VisualizeTemporalUpscaler” and noticed the frames that have missing motion vector data showed up as pops in the “show VisualizeReprojection” part of the visualizer. ...

Actors re-scale to original size when attached to other actors

UE - Gameplay - Nov 21, 2014

Actors rescale to their original size when placed in level then attached to another actor. ...

Changing code based component category causes component to become ineditable in blueprints

UE - Gameplay - Blueprint - Mar 27, 2015

When a component written in code has it's category setting changed in blueprint the rest of the details for that component will not be editable once the component is deselected and reselected. ...

Strange intermittent CCD behavior on constrained physics bodies

UE - Simulation - Physics - Oct 23, 2019

There is some strange issue with CCD where constrained CCD objects can get velocity nulled when hitting things while constrained, its very hard to reproduce normally in engine but happens often in V ...