Problem with material layers using interpolator nodes

UE - Rendering - Architecture - Materials - Jun 7, 2024

The Vertex Interpolator Material Expression appears to collapse separate instances from separate Material Layers, leading to visual artifacts when used. Also tested on UE5_Main, CL: 34200103 ...

Invalid DumpGPU capture when ProjectDisplayedTitle contains special utf8 chars

UE - Graphics Features - Mar 7, 2025

Placing a special UTF-8 character into the "ProjectDisplayedTitle" will result in GPU dumps failing to open. This appears to be because the dump will switch between us-ascii and UTF-16 file formats ...

Packaged project crashes when playing sound from blueprint library with enum input after nativizing blueprints

UE - Gameplay - Blueprint Runtime - Aug 23, 2016

Packaged project crashes when playing sound from blueprint library with enum input after nativizing blueprints. Frequency: 5/5 Notes If nativize blueprints is turned off, the packaged project wor ...

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 - Content Pipeline - 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 - Graphics 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 - Graphics 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 ...