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 ...

Complex Collision as Simple causes odd Overlap behavior

UE - Simulation - Physics - Jan 25, 2016

When triggering overlap events with a Static Mesh using Complex Collision as Simple, the overlap Begin and End events will be triggered rapidly in sequence. Changing to Default collision will fix t ...

Parent Begin Play node does not appear to run the parent code class BeginPlay() function before the rest of the Blueprint's Begin Play functionality

UE - Gameplay - Blueprint - Feb 19, 2015

If a Blueprint event graph contains a Begin Play node that connects to a call to the parent function, the functionality present in the Blueprint Begin Play segment is run before the parent Begin Pla ...

Cloth rendering issue on triangles sharing kinematic attachments.

UE - Simulation - Physics - Character - Jul 29, 2020

All render vertices on any cloth triangle that contains one or two fixed vertex are set as fixed, whereas this should only be the case if all three vertices were fixed. ...

Some post-processing passes sample outside of the viewport when using scene capture components

UE - Graphics Features - Nov 29, 2023

It looks like the SSAO shader does not clamp its sample space to the half view size for the two inputs "Ambient Occlusion" and "AmbientOcclusionSetup", leading to invalid data entering the edge of f ...

Calling DiscardPlayerInput() does not appear to actually discard the player's input

UE - Gameplay - Jun 19, 2018

Calling DiscardPlayerInput() does not appear to actually discard the player input. The comment for the function indicates that input will be consumed and discarded without doing anything with it. Ho ...

bIgnoreAllPressedKeysUntilRelease behaves differently for triggers in EnhancedInputAction and triggers in InputMappingContext

UE - Gameplay - Input - Aug 10, 2023

For actions that are triggered on the Input mapping context, simply adding or removing an InputMappingContext with no related key override with the bIgnoreAllPressedKeysUntilRelease option will caus ...

Physics constraint component doesn't work when placed inside a child actor, while using world partition and streaming is enabled

UE - Simulation - Physics - Mar 21, 2025

Context: In a World partition level, to reduce complexity and provide a scalable solution when creating new projects, grid cell streaming can be enabled. Problem: The problem is that physics constr ...

Improper Rendering of Paper Sprites in Translucent Sort Axis.

UE - Graphics Features - Apr 8, 2019

Regression as of 4.22. Translucent Depth Sort Policy results in improper rendering ( Z-Fighting flickering) with Paper2D Sprite Components. ...

Instanced EditInlineNew objects are parented to the CDO when used by a child BP of a parent BP that inherits from a native class

UE - Framework - Blueprint Runtime - Mar 21, 2024

EditInlineNew objects added to Instanced array stored in a struct are seemingly ignored and the object is instead parented to the CDO of the owner. The owner must be the BP child of a parent BP tha ...