Using /*/ to create multiline comments in header files can prevent Visual Studio from successfully building a project.

UE - Foundation - Core - Aug 7, 2015

If a multi-line comment is made in a header file using the format /*/ at the beginning and ending of the comment, UHT will fail to compile the project and will display the following errors: 1> C:/ ...

While using Rootmotion with blendout, the velocity will always fallback to 0.

UE - Anim - Gameplay - Apr 19, 2019

We skip CalcVelocity for CharacterMovement while HasAnimRootMotion, and we do ExtractedRootMotion.MakeUpToFullWeight() anyway.  This caused problem that when we blend out a rootmotion anim, it will ...

Particle Systems Feed Broken Values to Dynamic Parameters in Materials with Instanced Stereo Enabled

UE - Niagara - Jul 11, 2019

Particle Systems Feed Boroken Values to Dynamic Parameters in Materials with Instanced Stereo Enabled Working as expected in 4.21 CL# 4753647 Found in 4.22 CL# 7053642, 4.23 Preview 1 CL# 7236301, ...

Newly Created Landscape using Material with Displacement and Tessellation Flickers

UE - LD & Modeling - Terrain - Landscape - Apr 8, 2016

Upon creating a new landscape that uses a material with displacement and tessellation, the landscape and its respective components will flicker. The flickering can be removed when you begin sculptin ...

Pawns using Floating Pawn Movement will teleport to the location specified in Move To Location

UE - AI - Jul 14, 2015

Pawns using Floating Pawn Movement will teleport to the location specified in Move To Location. From fix CL 2619989: "Fixed FloatingPawnMovement component's issue when controlling AI pawn. Basicall ...

TBigInt allocates twice as much memory as necessary for FString input

UE - Foundation - Core - Jul 9, 2015

TBigInt appears to allocate twice as much memory as necessary for the input. This produces an unexpected output of the input value. ...

FPS drop after highresshot console command

UE - Graphics Features - Feb 25, 2019

Running the highresshot command with a multiplier of 6 or higher results in poor performance for the remainder of the Editor instance. Closing the PIE window does not improve performance, only closi ...

Record Animation can start "between keys"

OLD - Anim - Feb 8, 2016

A user was trying to make his recorded animation loop, but having trouble getting it to loop properly and having to eyeball it. So I did some digging and experimentation. I think that one of the m ...

FRotator::SetClosestToMe(FRotator) Doesn't Set The Correct Value

UE - Foundation - Core - Dec 10, 2019

FRotator::SetClosestToMe(FRotator) doesn't set the correct value. Attached are files with the demonstrative code. Found in 4.23.1 CL#9631420 Reproduced in 4.24 Preview 4 CL#10570792, 4.25 CL#10520 ...

SAnalogSlider moves slowly when step size is large

UE - Editor - UI Systems - Slate - Mar 6, 2024

SAnalogSlider calculates FastestStepTime by multiplying the step size value by a constant, resulting in high numbers for larger step sizes. This gets lerped from 1 and used as the repeat time, resul ...