Unreal Engine Issues
Unreal Engine Issues
High Virtual Texture Sample/Lookup Cost when using a Virtual Texture in a Material Layer Blend
UE - Rendering Architecture - Materials - Mar 14, 2025Some 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, 2015A 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, 2017Crash 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, 2017Particle 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. ...
Motion vectors not generating correctly in build
UE - Simulation - Physics - Nov 3, 2023Also 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. ...
Using "Change Class" on Spawnables, Possessable references retain old Class info
UE - Anim - Sequencer - Apr 22, 2024Changing Class for Spawnable objects in Level Sequence did not have any impact on Possesable objects in Subsequence. It's still referencing the previous Class. Also found in Release-5.4, CL: 329753 ...
Water tiles flicker in and out of visibility with instanced stereo enabled.
UE - Graphics Features - Jun 16, 2025Water tiles flicker in and out of visibility when playing in VR with instanced stereo enabled. Requires instanced stereo rendering to be enabled (does not require forward shading to be enabled) Must ...
Actors re-scale to original size when attached to other actors
UE - Gameplay - Nov 21, 2014Actors rescale to their original size when placed in level then attached to another actor. ...
If PIE is paused using the 'Pause key', the Pause or Resume buttons on the toolbar will no longer start PIE
Tools - Feb 5, 2015If PIE is paused using the 'Pause key', the Pause or Resume buttons on the toolbar will no longer start PIE. You have to make sure that the icon is toggled to Pause, select the viewport, and then p ...
Changing code based component category causes component to become ineditable in blueprints
UE - Gameplay - Blueprint - Mar 27, 2015When 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. ...