Duplicated TextureLoadVirtualPageTable in GetCustomData functions in generated HLSL add to the total instruction count due to TextureLoad having side effects

UE - Rendering - Architecture - Materials - Dec 4, 2024

When using materials with CustomData inputs, such as the Eye material with Iris Distance and Mask, Virtual Texture samples will increase the instruction count for each unique VTPageResult. Each cus ...

[Mobile/Forward Rendering] PlanarReflection does not work when the reflection plane faces certain directions

UE - Platform - Mobile - Sep 24, 2025

Note: This repros on 4.27 and all 5.x versions. When using the mobile renderer and/or forward shading, Planar Reflection will simply not work if the reflection plane normal has components that add ...

Blueprint Library plugin set to 'Runtime' doesn't work in Standalone/packaged builds if used inside of the 1st Person Character BP

UE - Foundation - Cpp Tools - UnrealBuildTool - Nov 18, 2016

Blueprint Library plugin set to 'Runtime' doesn't work in Standalone/packaged builds if used inside of the 1st Person Character BP. User Description: Blueprint libraries are still broken in the fi ...

Staging Directory in Project Packaging Settings should not be saved as absolute path

UE - Core - Data Pipeline - Cooker - Jun 8, 2021

When you package a project via the editor, it updates the ProjectPackagingSettings to set the StagingDirectory to the specific one chosen by the user. However, it saves this path as an absolute path ...

Updating Material does not update platform stats in derived Instance

UE - Rendering - Architecture - Materials - Nov 26, 2024

It would seem that updating a material does not update the associated platform stats in a material instance editor, only the parameters. Can workaround by manually invoking shader compile in the ma ...

ChaosCacheManager is not reproducing Trailing Events

UE - Runtime - Simulation - Mar 28, 2025

ChaosCacheManager (CCM) is not reproducing Trailing Events. Particles set to track Trailing Events correctly follow the position of the trailing event when the Geometry Collection (GC) is physically ...

GetRefBonePose doesn't return the correct location if the mesh has been switched to another mesh of the same skeleton

OLD - Anim - Sep 10, 2015

When using GetRefBonePose() on a USkeletalMesh's RefSkeleton, the given location is incorrect if the SkeletalMesh has been changed from one to another where both meshes share the same skeleton. Als ...

Packaging a project to HTML5 and opening the project disables mouse over events

UE - Platform - Mobile - Dec 24, 2015

Packaging a game to HTML5 disables the mouse and mouse over events on local host, which prevents any mouse functionality from working in a packaged project. ...

Destructible attached with a Physics Constraint ignores Start Awake on play

UE - Simulation - Physics - Destruction - Jul 26, 2016

Destructible attached with a Physics Constraint ignores Start Awake on play The Destructible component is set to simulate physics, but on play physics is not simulated unless the destructible is to ...

Preview Rendering Levels Do Not Display Supported Optimization Viewmodes in Viewport Dropdown

UE - Platform - Mobile - Apr 2, 2019

When attempting to set an optimization viewmode while using a Preview Rendering Level other than Shader Model 5, the Optimization Viewmodes dropdown is missing all of its options and instead display ...