Apple Motion 4 - Manual (Page 496)

Note: The Align to Motion behavior does not work on objects animated using the Motion
Path behavior. Instead, use the Snap Alignment to Motion behavior (in the Basic Motion
subcategory).
Before using Align To Motion After using Align To Motion
Unlike the Snap Alignment to Motion behavior, which produces absolute changes in
rotation that precisely match changes in direction, Align To Motion has a springy reaction
and creates a more lively effect.
In the above example, the fish travels along the keyframed animation path, but it isn’t
aligned to the animation path (notice the rotation handle). Using the Align To Motion
behavior, its angle of rotation moves so that it points in the direction of the animation
path. By adjusting the Drag parameter, you can make it careen wildly about its anchor
point as it goes around curves in the animation path.
Parameters in the Inspector
Affect Subobjects: This parameter appears when this behavior is applied to an object
that contains multiple objects, such as a group, a particle emitter, a replicator, or a text
layer. When this checkbox is selected, all objects within the parent object are affected
individually. When this checkbox is deselected, all objects within the parent object are
affected by the behavior together, as if they were a single object.
Rotation Axis: A pop-up menu that lets you rotate the object around the X, Y, or Z axis.
You can also select All to rotate the object around all three axes. The default rotation axis
is Z.
Axis: A pop-up menu that lets you specify whether the object aligns itself on its horizontal
or vertical axis.
Invert Axis: A checkbox that flips the orientation with which the object aligns itself to
the motion.
Spring Tension: A slider that adjusts how quickly the object’s rotation changes to match
a change in the object’s direction. Lower values create a delay between a change to an
object’s position and its subsequent change in rotation. Higher values create more
responsive changes in rotation.
496 Chapter 9 Using Behaviors