Custom Primitive Data color widget not applying correctly to static mesh components in Blueprint editor.

UE - Rendering - Architecture - Materials - Jul 23, 2025

Context Custom Primitive Data is used to store custom data in an index array that is accessible through Blueprint and code. This allows for variations across instances of the same mesh without needi ...

Temporal blur artifacts on Geometry Cache Components in Blueprint actor

UE - Editor - Open File Formats - Alembic - Jan 9, 2026

When a Geometry Collection is in a Blueprint, attached to other components, it can render incorrect motion vectors at some angles. In the test project, any angle that is not a multiple of 45 will re ...

GetAllocatedSize returns inaccurate number of bytes

UE - Foundation - Core - May 20, 2015

When calling GetAllocatedSize() on a TBitArray it will round down the result of MaxBits / NumBitsPerDWORD. This means that not enough bytes are allocated when the MaxBits is not divisible by NumBi ...

Toggling a Spline component from an open/closed loop through bp's isn't reflected

Tools - Jan 19, 2015

Toggling a Spline component from an open/closed loop through bp's isn't reflected ...

The OnUnPossess() method of the AAIController class is triggered twice

UE - AI - Apr 21, 2020

The OnUnPossess() method of the AAIController class is triggered twice ...

Light Function and World Position in 5.4

UE - Rendering - Features - Nov 4, 2024

When rendering a Light Function into the Translucency Lighting Volume, the World Position Material Expression returns the position relative to the Camera (unrotated), not the World. This can be mor ...

Groom Hair Visual Issue with RBF Interpolation Enabled

UE - Rendering - Features - Feb 19, 2025

When "RBF Interpolation" is enabled in the Groom settings, applying an Animation Sequence to a Skeletal Mesh that animates at a position far from the world origin causes the bound Groom shape to bec ...

Scene Capture 2D will default back to View 0

UE - Graphics Features - Oct 8, 2015

The scene capture will revert back to the Character BP that is placed in the level when player 2 is not moving. When they are moving the scene captuer will show correctly. You can get around this ...

Moving all the related assets to another folder at once leads to reference lost in the contents browser.

UE - Editor - Content Pipeline - Content Browser - Aug 23, 2017

Moving all the related assets into another folder leads to reference lost. This can be tested out using ShooterGame project. Also you can find materials in the skeletal mesh lost its texture. This ...