The object
The key to animate
To goal value
Approximate time to reach the target. A smaller value will reach the target faster.
Frame delta, for refreshrate independence
Optionally allows you to clamp the maximum speed. If smoothTime is 0.25s and looks OK going between two close points but not for points far apart as it'll move very rapid, then a maxSpeed of e.g. 1 which will clamp the speed to 1 unit per second, it may now take much longer than smoothTime to reach the target if it is far away.
Easing function
End of animation precision
Damp, based on Game Programming Gems 4 Chapter 1.10 Return value indicates whether the animation is still running.