Using Interactive Sketch Interpretation to Design Solid Objects

摘要

Before the introduction of Computer Aided Design and solid modeling systems,designers had developed a set of methods for designing solid objects by sketching their ideas using pencil and paper, and refining these ideas into workable designs. These methods are different from those used for designing objects with a conventional solid modeler. Not only does this dichotomy waste a vast reserve of talent and experience (people typically start sketching from the moment they first pick up a crayon), but it also has a more fundamental problem: designer can use their intuition more effectively when sketching than they can when using a solid modeler. This dissertation introduces interactive sketch interpretation as a new user interface paradigm for solid modeling systems. Interactive sketch interpretation makes it possible to use the computer as a sketchpad for designing three-dimension objects. The premise behind interactive sketch interpretation is to let the designer change an object's design by modifying a computer generated the line drawing of the object. Sketch interpretation maps the designer's changes onto a boundary representation model of the object. The designer can continue the design process by then changing the line drawing of the modified object. This design cycle is highly interactive and, as a result, incorrect interpretations can be easily corrected by the designer. Viking is a solid modeling system whose user interface is based on interactive sketch interpretation. With Viking, the designer can modify his or her design by either changing the line drawing or placing geometric constraints on the object. Sketch interpretation changes Viking's model of the object so that it is consistent with the modified line drawing and the geometric constraints placed by the user.