Opaque GPU particles appear later than translucent one when Collision module is enabled

UE - Niagara - Rendering - Apr 2, 2024

When spawning GPUCompute Sim Niagara system which is consist of opaque particle emitter and translucent one, if those emitters use Collision module, opaque particle often appears one frame later tha ...

Adding new elements to an array in code does not update in a class based blueprint on compile

UE - Gameplay - Blueprint - May 5, 2015

When adding elements to an array inside a code class, blueprint instances of the class do not have their array updated after a hot reload. ...

Collision outcome is different between PIE and Mobile Preview/Packaged Project.

UE - Simulation - Physics - Mar 25, 2015

When playing the user's project in editor vs Packaged, there has been different results for the enemies collision. When playing in PIE, you are able to fly through the enemies with no issues. When p ...

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 ...

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 ...