Incorrect shading for SubSurface profile in the Blueprint Viewport.

UE - Graphics Features - Dec 30, 2016

The Subsurface shading looks incorrect in the Blueprint Viewport window. Adjusting the cvar for r.sss.checkerboard from the default value of 2 to 1 looks more correct and a value of 0 switches back ...

Major performance drop with instanced meshes since PhysX 3.4 upgrade

UE - Simulation - Physics - Mar 15, 2017

Major performance drop with instanced meshes since PhysX 3.4 upgrade Regression: YES Worked: 3172292 (4.13.2) Broken: 3249277 (4.14.3) For me, my results were: 4.8 through 4.13 No Collision - ...

Editor Crashes when importing some FBXs with multiple Material IDs in 4.14.2

UE - Editor - Content Pipeline - Import and Export - Jan 5, 2017

This is a regression in behavior between 4.14.1 and 4.14.2! The editor will crash when importing FBX meshes that have multiple material ID assignments. If it's a single material ID it will import w ...

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 ...

Float Curve evaluation may yield completely wrong results due to floating-point precision issue

UE - Anim - Runtime - Oct 31, 2024

Note: This is possibly related to [Link Removed]. For some inputs, function UE::Curves::WeightedEvalForTwoKeys() inside file "CurveEvaluation.cpp" can incorrectly return the value of the first key, ...

Blurry RVTs after camera jump

UE - Graphics Features - Aug 7, 2025

When using Runtime Virtual Textures (RVT) on landscape in UE 5.5+, nearby tiles may remain blurry (low-resolution mips) after launching PIE or making large camera jumps (e.g. via bookmarks or viewpo ...

Switching a code project created in a source-built Engine to use the binary Engine results in files being deleted from the binary Engine installation

Tools - Nov 18, 2016

If a code project is created in an Engine built from source code, and then it is switched to use a binary Engine installed by the Launcher, building the project in Visual Studio will result in numer ...

Broken hair material with light function

UE - Graphics Features - Dec 19, 2024

Hair Materials do not react to Light Functions in the same way as other Materials. There is a visual difference between a Directional Light at 1 lux with no Light Function and a Directional Light at ...

"Enable Stencil Test" Mobile crash

UE - Graphics Features - Sep 10, 2019

A material with 'enable stencil test' will crash on mobile. Enable Stencil Test is a new option in materials as of 4.23 Confirmed with OpenGL 3.1 + 2 and Vulkan on Pixel XL Also Crashes on iOS ...

Behavior of Speed Up/Down parameter of Auto Exposure are different.

UE - Graphics Features - Apr 5, 2016

Brend/Swtch multi PostProcessVolume to handle Auto Exposure with same Speed Up/Down parameter but behavior of Speed Up/Down parameter of Auto Exposure are different. Scene with. Unbounded PostProce ...