Unreal Engine Issues
Unreal Engine Issues
Major performance drop with instanced meshes since PhysX 3.4 upgrade
UE - Simulation - Physics - Mar 15, 2017Major 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, 2017This 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, 2018Particle 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 - Runtime - Animation - Oct 31, 2024Note: This is possibly related to [Link Removed] Backlogged . For some inputs, function UE::Curves::WeightedEvalForTwoKeys( ...
Blurry RVTs after camera jump
UE - Rendering - Features - Aug 7, 2025When 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, 2016If 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 - Rendering - Features - Dec 19, 2024Hair 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, 2019A 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, 2016Brend/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 ...
Manually importing LODs are rotated 90 degrees when using Transform Vertex to Absolute
Tools - May 26, 2016When importing a Static Mesh if you use the default settings and then manually import any LODs for that static mesh they will be rotated by 90 degrees. I found that disabling Transform Vertex to A ...