Passing array from blueprint to C++ causes performance drop

UE - Gameplay - Blueprint - Sep 8, 2015

Passing a blueprint array as an argument to a C++ function causes a spike in Frame rate, game and GPU. This spike is noticeable when using UnitGraph. Attached screenshots show difference in UnitGr ...

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 ...

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

UE - Graphics Features - 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 ...

SplineMeshComponent's collision will start to distort the longer the Spline becomes

UE - Gameplay - Nov 30, 2016

SplineMeshComponent's collision will start to distort the longer the Spline becomes This is a regession. It was working in 4.13.2-3172292 User Description: When drawing out a long spline mesh ( r ...

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 ...

Some materials render black on Iphone 6 series phones

UE - Platform - Mobile - Oct 6, 2016

Some materials are not rendering on iphone 6 series devices. They will render completely black on one device but not others in the same series. Replacing the material with a basic material renders o ...

Geometry in sublevel created with "Load Level Instance" ignores level transform

UE - LD & Modeling - Modeling Tools - BSP - Sep 26, 2017

Geometry in sublevel created with "Load Level Instance" ignores level transform. Other objects, such as Static meshes are affected by the transform. This issue is not a regression. Versions tested: ...

Morph Targets flicker Randomly in Slave Mesh

OLD - Anim - Oct 1, 2015

When a mesh is slave to a master mesh, its morph targets will flicker when Played in Editor. This does not occure with the same assets in 4.8. This has been reported by at least two different use ...

Invalid array length error launching QAGame onto HTML5

UE - Platform - Mobile - Mar 22, 2017

Firefox 32-bit Version 52.0.1 This error also occurs in MainRangeError: invalid array length[Learn More] 0943e4e3-83fc-4463-accc-9fd15fd7df6c:157:9 processPackageData blob:http://localhost:53501 ...