The pivot point of the Sprite, relative to its bounding rectangle.
The pivot point is usually specified in (x, y) values within a range of (0-1). For example: The upper left of the rectangle is (0,0); the bottom right of the rectangle is (1,1), and the center of the rectangle is (0.5,0.5).
The pivot point can also be placed outside the bounding rectangle. Do this by using values outside the (0-1) range. For example: A position central but far above the bounding rectangle is (0.5,-2). A position in line with the bottom of the bounding rectangle and to the far right outside the bounding rectangle is (3,1).