Extrapolation defines the shape of the animation curve outside the keyframes. You can set up a cycle in which channel values change repeatedly in the same manner over time. You can set the extrapolation before the first keyframe separately from the extrapolation after the last keyframe.

You can specify how keyframes are extrapolated using the following settings.

ConstantCreates an extrapolated animation curve that stays at the same value as the first or last keyframe.

LinearCreates an animation curve that changes in a linear fashion before the first or after the last keyframe.

RepeatCreates a mirror image of the animation curve before the first or after the last keyframe.

CycleCreates a pattern of repeating keyframes before the first of after the last keyframe.

To set the extrapolation type for a channel:

1. Select the keyframe for which you want to set the extrapolation.
2. Click Animation, and then click Setup.

   The Animation Setup menu appears.

   
   

   (a) PreType extrapolation  (b) PostType extrapolation  

3. In the PreType controls, click one extrapolation type button to set the extrapolation before the first keyframe.
4. In the PostType controls, click one extrapolation type button to set the extrapolation after the last keyframe.