The Design And Implementation Of A 2D CAD System Supporting Conceptual Design

This thesis focuses on the study of a new style 2D CAD technology, which is to support conceptual design process, and to integrate it with consequent detailed design process. A novel sketch-based interface is introduced into the 2D CAD system. This technology will change traditional 2D CAD system greatly: it will make full use of sketch-based drawings in detailed design, and be usable.In order to implement such a system, a set of gestures and a framework to capture these gestures should be designed carefully, which should be natural, reasonable and efficient enough for users. In the system, this thesis makes broad studies about the users, the environment and the task itself while putting usability engineering into effect.In this thesis, the idea about the system's development, and some relative techniques such as gesture design and recognition are studied in detail. The principles and the implementation of recognition and understanding of sketch-based drawings are studied in it, too. And in further, the symbolizing feature of 2D drawings is studied as well. Finally, a method which uses object-based knowledge-base to make the system more intelligent is presented.With the study of this thesis, a prototype system will be implemented.