Apple Motion 4 - Manual (Page 548)

Combining Behaviors and Keyframes
Because it is possible to add keyframes to an object that may already have a behavior (or
many behaviors) applied, it is possible that these two methods could conflict. For example,
you might apply a Throw behavior toward the upper left, and at the same time add
keyframes that instruct the object to move to the right. Now what?
Behavior motion path Keyframe animation path
The way Motion handles this sort of conflict is that the instructions are added together,
giving you a combination of the two sets of instructions. In the above example, the object
would move toward the upper left, but it won’t get as far, because the keyframes are
pushing it in an opposing direction.
Combined animation path
The larger the Throw velocity rate, the more it overpowers the keyframes, and vice versa.
548 Chapter 10 Keyframes and Curves