Combining Behaviors with Keyframes
Any object can have behaviors and keyframes applied to it simultaneously. When this
happens, the values generated by the behavior and the keyframed values applied to the
parameter are combined to yield the final value for that parameter. This lets you combine
the automatic convenience of behaviors with the direct control of keyframing to achieve
your final result.
Note: Motion has a specific order of operations for keyframes and behaviors. For more
Behavior Order of Operations
For example, if you create an animation path using keyframes, you can create a completely
predictable and smooth movement.
However, if you apply the Randomize parameter behavior to the same object, its effect
combines with the motion path you created. As a result, the animation path follows the
general direction you want, with random variation in it to make it interesting.
Although this example shows how you can combine behaviors and keyframes to create
animation paths, you can combine behaviors and keyframes for any parameter.