It's easier to work with Bezier objects if you understand how surface patches are constructed and manipulated. The following illustration describes the basic structure. Think of a simple rectangle, with its single surface patch, as a sub-set of more complex objects with multiple surface patches; the behavior is the same.
As long as the vertex point you are moving is shared by adjacent patches, the surface responds in a smooth, predictable way.
· Use the Add Point tool to add a point. Click on the surface where you want the point added. More points require more memory, so only use what you need.
· Select the points you wish to remove and press the Delete key.
· Hinged vertices allow you to crease the surface. To hinge a vertex point so that you can move its direction handles independently, hold down the Option key (Macintosh) or Alt key (Windows) while dragging the direction handle you want to hinge.
· Aligning them makes the surface smooth at that point. To align the direction handles of a vertex point that you have previously hinged, grab one of the handles and line it up with the opposite handle. When it's aligned, the handles snap into position.
An Align Handles button is also provided in the Commands tab of the Extensions palette that can be used to align selected direction handles. This command is especially useful when a single set of direction handles reside on two different planes.