about vector interpolation

Many of you guys already know that vector interpolation might have different result than you think.

As you can see the below image, red arrow is a forward vector and green arrow is a right vector of the character.

If you interpolate forward vector to right vector, you will get below image.

This is because I didn't account of angle of vector. If I account of angle of vector then I'll get different result like down below.

In unreal engine 4, There are related functions exist.

FMath::RInterpTo is for linear interpolation.
FQuat::Slerp is for spherical linear interpolation.