Apple Motion 4 - Manual (Page 305)

As you drag the rotation handle, the original angle of the object is indicated by a small
circle that appears on a larger circle surrounding the object’s anchor point. Additionally,
an info window appears, showing you the new angle of rotation and the delta of change
between the object’s former angle and the angle to which you’ve dragged it.
Using the Adjust Anchor Point Tool
Using the Adjust Anchor Point tool, you can move any object’s anchor point, changing
the way in which different geometric transforms are performed.
Objects rotate around the anchor point, but the anchor point also affects shearing and
resizing operations. For example, the default anchor point for any object is the center of
the bounding box that defines its edges. If you rotate an object, it spins around this central
anchor point.
305 Chapter 7 Basic Compositing