The light in the Blueprint Editor's Preview Scene does not respond to any lighting channel but 0.

UE - Framework - Blueprint Editor - Jun 28, 2024

In the Blueprint Editor, Primitive Components can be configured to respond to Lighting Channels 0, 1, and/or 2. However, if channel 0 is disabled (even with another one enabled), the Preview Actor's ...

Contact shadows bug in splitscreen

UE - Graphics Features - Dec 11, 2024

Screen Space shadows do not check the view boundary. This can cause extra shadows in split screen, as one view can cast shadows in another view. ...

Artifacts in imported GLB and GLTF files

TM - Interoperability - Mar 10, 2025

Reported in SF [Link Removed] Client reports that many of their GLB and GLTF files they use appear with visual artifacts when imported to Twinmotion. These artifacts only appear in Twinmotion and n ...

Lack of multi-bounce when using software traced lumen radiosity

UE - Graphics Features - Lumen - Apr 4, 2025

Certain Lumen Hardware Ray Tracing CVars, when disabled in isolation, will not fall back to tracing the Global Distance Field, because the Global Distance Field is still disabled. The function "Lum ...

Assigning a static mesh to a Mutable Clip Mesh With Mesh Node can crash the editor

UE - Anim - Mutable - Jul 4, 2025

Context: The Mutable plugin has a modifier node called Clip Mesh With Mesh that allows Static Mesh modifiers to be assigned as the clip mesh. Under certain circumstances, an assert can be triggered ...

Simulate Physics with Destructible that is using World Support can't be enabled after it's been hit.

UE - Simulation - Physics - Destruction - Apr 22, 2015

When using a Destructible with World Support set simulate physics can be enabled so long as the DM has not been hit yet. Once it's been hit it no long is able to be set to simulate. ...

Camera behavior mismatch between PIE vs Packaged game

UE - Gameplay - Feb 19, 2015

When a camera is setup in code with GetWorld()->GetFirstPlayerController()->SetViewTarget(this); the camera will work in the editor but a packaged version of the game has a black screen. ...

Unable to Import Sockets and LODs together for Static Meshes

Tools - Nov 6, 2015

When importing a Static Mesh into UE4 that is using the SOCKET_ naming, and is part of a Level of Detail set, the socket is discarded. If the Level of Detail set is removed from the Static Mesh, t ...

Setting linear dampening during runtime via the event graph does not work for separated chunks

UE - Simulation - Physics - Destruction - Dec 18, 2014

DESCRIPTION: When using a DM in blueprints and setting the linear dampening in the event graph the DM will honor the linear dampening but the chunks as they break off will not. Setting the mesh to ...

Extremely long Spline Point will cause the editor to lose FPS

Tools - Nov 13, 2015

Extremely long Spline Point will cause the editor to lose FPS and crash some machines User Description: A couple of times I've accidentally scaled a spline node to be huge, causing the spline to ...