Apple Motion 4 - Manual (Page 587)

To apply the After Last Keyframe setting for a parameter
µ
In the Keyframe Editor, open the Animation menu for the parameter you want to change,
then choose an item from After Last Keyframe submenu.
The following table describes the extrapolation options available in the Before First
Keyframe and After Last Keyframe submenus.
Description Example Extrapolation method
(Default) The parameter remains at the exact value
of the first and last keyframes in the extrapolated
area. Constant
Extends the curve beyond the first and last
keyframes uniformly, along the existing trajectory. Linear
Copies the curve and repeats it, alternating
forward and backward. Ping Pong
Duplicates the curve, applying it again and again. Repeat
Extends the curve by repeating the existing shape
of the curve, but rather than returning to the exact
same values, it begins again from the existing end
value. Progressive
Reversing Keyframes
Using the Reverse Keyframe option in the Keyframe Editor, you can quickly “flop” time
by reversing the keyframes on a curve.
587 Chapter 10 Keyframes and Curves