"Fix root motion initial rotation handling" commit breaks root motion completely

OLD - Anim - Dec 18, 2014

Enabling and processing root motion causes animation to rotate the wrong direction. Roll instead of Yaw. Pitch instead of roll etc. This error does not occur in UE 4.6. ...

Fix the skeletal mesh merge tool material assignment, change the API to avoid confusion

OLD - Anim - Jul 25, 2018

UDN user ask us to change the API for the material to remove confusion with the material ID. Also apparently there is an issue with the skeletal mesh merge tool, the user did not give any repro ste ...

Level Bounds Incorrectly Calculated If Particle System Does Not Have "Use Fixed Relative Bounding Box" Enabled

UE - Niagara - Jul 26, 2018

If "Use Relative Fixed Bounding Box" is disabled, level bounds will be incorrectly calculated. This seems to be similar to [Link Removed]. Found in 4.19 CL# 4033788, 4.20 CL# 4212847, 4.21 CL# 4233 ...

Backout attempted fix for - AutoSize triggers ensure on shortened Skel Anim Section moved past anim length

zComponent - Archive - May 29, 2026

In Sequencer, calling "Edit > Auto Size" on a UMovieSceneSkeletalAnimationSection triggers the LowerBound > UpperBound ensure in UMovieSceneSection::SetRange (MovieSceneSection.h:333) when the secti ...

Fix PrimitiveComponent overlap indirection

UE - Simulation - Physics - Sep 27, 2016

When doing overlap tests in PrimitiveComponent, UWorld->ComponentOverlapMulti is used. The callstack for that ends up looking like this (callstack is inverted, highest level on top): UWorld::Compo ...

Pre-UE5 serialized FVariant FVector data corruption when deserialized in UE5

UE - Framework - LWC - Jan 15, 2024

FVariant is a struct that implements a union of data types, including FVector. When assigning an FVariant an FVector value in engine versions UE 4.27 or earlier, the FVariant will deserialize incorr ...

Significant Refraction Differences between 4.27 and 5.0

UE - Rendering - Architecture - Materials - Apr 25, 2022