The Study And Application Of Professional Automatic Graphical-Base System

AutoCAD is a good software for Computer-Aided Design(CAD) developed by AutoDesk Company, but it is not a commonly used one and has no parametric environment. Therefore, when we draw a very complex figure, the communication between user and computer is very complicated, and the inputing amount of the drawings is also very large. Thus it is necessary to develop the parametric drawing on AutoCAD .Parameterized design and feature-based modeling technologies are very important research fields in current CAD technology, and are often adopted in CAD systems. The technology of CAD has been used widely in the field of mechanical design and other fields as a new advanced technology, which has changed the whole process of design enormously.The featured-based modeling system is usually used in the 3D design system. But the training of users, who are already familiar with the design process based on 2D draftings, is proved to be a costly and sticky tack. In addition, the prospect of using 3D model as the conmmunication media in real engineering drawing conventions, the role of 2D drafting will not be completely repaced by drawings generated from 3D models in the foreseeable future.The main research content of this subject is to carry on the secondary development of AutoCAD, set up one can suitable for many fields' automatic graphical system. The emphasis is the feature-based parameter technology, feature modeling, the drawing of complex curve and carrying on the studying of secondary development on AutoCAD platform . Because this system is mainly manage various kinds of two-dimentionally graphic elements, and realize the design of the plane figure. So we can't use traditional feature-based parameter technology to set up the graphic element's model directly. On the analysis of the feature-based parameter technology, author adopt simple define of feature and restriction to set up the model. I use the Object-Oriented method to develop the system, utilize the encapsulation and inheritance describing the feature of graphic element. Using the Object-Oriented Database as the substrate, I set up deferent class to manage and store the data in this system.This system is based on AutoCAD 2000, utilize the Object -Oriented characteristic of the developing tool ObjectARX, take Visual C ++ and Visual LISP as developing language to realize.