Implied Decal Blend Modes don't properly account for Material Attributes usage

UE - Rendering - Architecture - Sep 28, 2021

I've attached a project with the necessary materials that demonstrate this issue. I would expect that just because a Set Material Attributes node is inside a material graph it wouldn't affect the de ...

Particles Do Not Obey Lighting Channels

UE - Niagara - Apr 17, 2018

Particle systems ignore lighting channels - no matter what channel a light is on (even if no channels are selected), it will affect lit particles. Changing lighting channels on the particle itself h ...

Lighting on Paper 2D Tile Maps is Broken

UE - Graphics Features - May 8, 2018

In 4.18.3 this feature is working. In 4.19.2 the feature is broken. Per User: Half of the Lights Cone or Sphere will properly interact with the TileMap as intended, the other half will not for wha ...

Sequencer Render: Animation not updating for a moment on camera cut

UE - Anim - Sequencer - Mar 17, 2017

When rendering from sequencer to an image sequence, character animation stops for 2 frames after a camera cut. This hitch does not occur when playing the sequence in PIE I've attached some sample d ...

Long thin spinning objects take too long to stop spinning

UE - Simulation - Core - Jun 5, 2023

See the SpinningObjectStability test map in the Physics Sandbox. [Link Removed] It's not clear if this is a bug or a side effect of some of our solver shortcuts (e.g., omission of the precession te ...

Cable Actor becoming stiff when bound to two dynamic objects

UE - Simulation - Core - Jun 1, 2023

the cable actor does not dynamically deform when the cable actor's parent mesh moves. Instead, the cable actor becomes rigid between the meshes it's bound between. This bug does not occur in the fo ...

Landscape displaces after converting file to Twinmotion 2026.1

TM - Core - Apr 23, 2026

Reported in SF [Link Removed] The client has a file from Twinmotion 2025.2 that contains a sculpted landscape. When converting the file to Twinmotion 2026.1, the landscape becomes displaced from it ...

Crashes when playing Slomo on NiagaraSystem with Solo and DesiredAge.

UE - Niagara - Mar 23, 2023

When Slomo 2 is used to speed up the process, TicksToProcess is greater than 1, which means that ManualTick is called several times during one loop.  When playback is completed by a ManualTick in t ...

Linux Native Toolchain depends on libninfo5 which is not bundled

UE - Platform - Linux - Sep 6, 2019

libtinfo.so.5 => /lib/x86_64-linux-gnu/libtinfo.so.5 (0x00007fc27cf4d000) bschaefer@bschaefer-Precision-T7600:bin$ ldd ./clang linux-vdso.so.1 => (0x00007ffceefe3000) libpthread.so.0 => /lib/ ...

Sub Surface Shading Model has Strange Blotch Color Artifacts when Used with a Ambient Cubemap

UE - Graphics Features - Sep 23, 2019

Sub surface shading model has strange blotch color artifacts when used with ambient cubemap. Since the subsurface profile shading model can't be used with ambient cubemap I wanted to use the regular ...