UV merging issue when merging meshes with multiple materials

UE - LD & Modeling - Modeling Tools - Mesh Editing - Jul 15, 2019

See https://udn.unrealengine.com/questions/505632/view.html for more details Repro: -Have a mesh with 3 sections and 3 materials, assign section 1 to material 1 and section 2&3 to material 3. -Pla ...

UActorFactory::PostSpawnActor gets called twice when an actor blueprint class is dragged into the scene

UE - Gameplay - Jan 11, 2019

Whenever dragging and dropping an actor to the Scene, the function UActorFactory:: PostSpawnActor gets called twice. Tested in 4.20.3 (CL - 4433814), 4.21.1 (CL - 4705082), 4.22 (CL - 4708082) ...

Shadows flicker when using spotlight

UE - Graphics Features - Jun 5, 2019

The shadows on a spotlight flicker whenever the camera is moved.  Tested in 4.20.3 (CL - 4369336), 4.21.2 (CL - 4753647), 4.22.2 (CL - 6547378), 4.23 (CL - 6845209) ...

Editor crash when Landscape Comp. LODBias set to value greater than 0

UE - LD & Modeling - Terrain - Landscape - Mar 20, 2018

When LODBias for a landscape component is set to anything greater than zero, the editor will crash. Reproduced in 4.19.0 CL 3944462 and 4.20 Main. Not able to be reproduced in 4.18.3 CL 3832480. T ...

PressMethod is not called in UButton::RebuildWidget()

UE - Editor - UI Systems - Slate - Nov 5, 2018

The void function UButton::RebuildWidget() does not call PressMethod when rebuilding the widget. Tested  4.19.2 (CL- 4033788), 4.20.3 (CL - 4369336), 4.21 (CL - 4537669), 4.22 (CL - 4531805) ...

Hot Reload cannot be performed when using the DebugGame Editor configuration

UE - Foundation - Cpp Tools - Hot Reload - Dec 31, 2018

In 4.21.1 it is no longer possible to perform a Hot Reload when the game is open in the Editor and using the DebugGame Editor configuration. REGRESSION: Yes. A Hot Reload was possible in 4.20.3 whe ...

OnAudioPlaybackPercent doesn't work after restarting the project

UE - Audio - Feb 7, 2019

Using the OnAudioPlayback event in Blueprints does not work when playing the audio component its connected to while PIE, after restarting the project. Tested in 4.20.3 (CL - 4369336), 4.21.2 (CL ...

Widget With Spinbox Crashes When Destrcutor Is Called With Multithreaded Destruction Enabled

UE - Foundation - Core - UObject - Feb 28, 2020

When a widget with a spinbox is calls it's Destructor with "Multithreaded Destruction" enabled the engine crashes. I have tested in 4.23.1, 4.24.3, and 4.26 Main with "Multithreaded Destruction" dis ...

DrawMaterial() Function not Rendering Translucent Material to HUD

UE - Graphics Features - Sep 4, 2015

After creating a new HUD blueprint class and calling it to render a translucent material, the material does not render at all. This is not the case with any other Blend Mode when called to render to ...

Ribbons Don't Follow Their Source Particles When Scaling

UE - Niagara - Mar 23, 2020

When Ribbon Data in a particles system that is following is scaled in an instance the ribbons scale appropriately, but they don't follow updated location of their source particles. See the attached ...