Apple Motion 3 - Manual (Page 400)

400 Chapter 5 Using Behaviors
Combining Behaviors and Keyframes in the Keyframe Editor
When you display a parameter that’s affected by a behavior in the Keyframe Editor, two
curves appear for that parameter. An uneditable curve in the background displays the
parameter as it is affected by the behavior. There are no keyframes over this first curve.
Superimposed over the curve displaying the behavior’s effect is the parameter’s
editable curve.
You can keyframe a parameter either before or after applying a behavior to the object
that affects it. When you keyframe a parameter that is already affected by a behavior,
the value of the keyframed curve is combined with the value generated by the
behavior at each frame, which either raises or lowers the resulting value displayed by
the background curve. The background curve doesn’t just display the behavior’s
animated values, it displays the sum of all values affecting that parameter.
Behavior effect curve Editable curve
Behavior effect curve Editable curve