How to get an angle between 2 Vectors?

[spaceharry]

This is from the VR Expansion Plugin for the “shortest” angle between two vectors.

FVector vec1;
FVector vec2;

float Angle = 0.0f;
FVector nAxis;

FQuat BetweenQuat = FQuat::FindBetweenVectors(vec1, vec2);

BetweenQuat.ToAxisAndAngle(nAxis, Angle);

Angle will then be in radians.