Huge performance hit when recording a demo (demorec)

UE - Networking - Jun 3, 2019

The current engine version (4.22) seems to suffer a huge performance hit when using the demo recording (demorec) feature. This issue is present in both the editor and the packaged game (developer bu ...

4.24 Instanced Stereo Distortion Error in ComputeBufferUVDistortion

UE - Graphics Features - Nov 13, 2019

4.24 moves distortion calculations to the file DistortionCommon.ush and its`ComputeBufferUVDistortion` function. The code in the INSTANCED_STEREO define no longer works as `Interpolants` isn't passe ...

Editor Content remains visible in 4.25 preview when set to hidden

Tools - Apr 22, 2020

Editor Content remains visible when selecting a Static Mesh for a Cube Actor in 4.25 preview even after setting Engine content to hidden.  ...

Compilation error in Mac editor builds when adding UWorld::IsStreamingLevelBeingConsidered function

UE - World Creation - Worldbuilding Tools - Jun 30, 2023

This code passes the build when compiled using the windows editor (Visual Studio), but fails when compiled using the mac editor (XCode). Adding ENGINE_API to struct FStreamingLevelsToConsider and ex ...

SkeletalMeshComponent in dedicated server causes memory leak

UE - Graphics Features - Nov 8, 2023

As dedicated server does not have viewport, USkinnedMeshComponent::BoneTransformUpdateMethodQueue array keeps growing and never clear. ...

Reference to material collection by Index instead of by Name causes inconsistency

UE - Rendering Architecture - Materials - Feb 21, 2024

A UDN user reports materials referincing parameter collections by index instead of by name. The problem manifests itself when rearranging the order of parameters belonging to collections, as the edi ...

Lumen doesn't use correct sky light settings when GI scalability changes from Low to High

UE - Graphics Features - Lumen - Sep 24, 2024

When the Global Illumination scalability settings are changed in the editor from High to Medium, they primarily act on the r.Lumen.DiffuseIndirect.Allow and r.SkyLight.RealTimeReflectionCapture.  No ...

Mouse Position doesn't properly update on tick when framerate is low in standalone game

UE - Editor - UI Systems - Slate - Dec 11, 2015

If a game is run in the standalone editor and the FPS drops to ~20-30 FPS, pressing an event such as LMB and returning the mouse position on tick will cause the tick to jump inconsistently. Note: ...

Crash When Curve Editor is on When Animating Button Transform in Widget Blueprint

UE - Editor - UI Systems - Mar 18, 2016

In a Widget Blueprint, after animating a button to transform vertically (possibly other directions) with the Curve Editor active, engine will crash upon creating a second animation. ...

Engine Crash When Enabling Distance Field Global Illumination and Opening TM-LightingFeatures

UE - Graphics Features - Jan 11, 2017

I was able to open the level once and after a few seconds of being opened the editor crashed while compiling shaders and generating mesh distance fields. Since then I have not been able to open th ...