Point-attached Polygons.
A point-attached polygon only changes form/position when a single control pointÑthe point to which it is attachedÑchanges position. The user defines two states for the polygons, one showing how it should look when its control point is at its max position, the other corresponding to its min value (Figure 11). When the control point is moved during animation, a linear interpolation is performed between the polygonÕs two states.