Research On Constraint Solution Based On Interactive Feature Modeling System

The current mainstream CAD software is feature modeling system based on the parameter or variable-oriented, but in the feature modeling system, the effectiveness of the modified feature maintenance is the key to the feature modeling. Geometric constraint solving technology is one of the most important technologies. The article is situated in the Microsoft Visual Studio 2008. NET software development environment, through the use of OpenGL as the 3D graphics API, an interactive operation of CAD software was achieved; feature validity maintenance, constraint solving strategies and methods were studied.Good user interface can greatly shorten the distance between people and computers, making computers easy to learn, easy to understand, convenient to users, improve work efficiency, reducing the use of the computer's error rate. The article searched picking up 3D geometric primitives in the selection and feedback rendering mode of OpenGL and proposed a method to solve the interactive operation using delegate in the event- driven manner. Because of using a delegate events can dynamically be subscribed and unsubscribed, therefore it can enhance the design flexibility of the operational class or interface.The problems geometric modeling techniques are related to the correct final result shows of model design. In this article, studied geometric modeling method in OpenGL to render Non-convex polygon, surface and stretch feature. It not only simplifies the design of geometric shapes, but also produces a realistic image through lighting and the surface material.Maintenance is the difficulty in the editing process of a feature. The article achieved geometry changes by using the command stack, and then verified the effectiveness of features to carry out features of the reconstruction. Because of only needing calculating the characteristic parameters of the affected part calculation do not have to start from the beginning and it can improve the system performance of solving.The quality of the geometric constraint solving methods is related to the feature-based modeling drawing speed, causing a direct impact on system performance. First of all, the article took advantage of the undirected graph of geometric constrain based on the degree of freedom and then reduced the number of simultaneous equations of geometric constraint equations, then used the adaptive search algorithm for constraint solving. As the adaptive harmony search algorithm, there are many merits of algorithm designing simply, rapid convergence and the performance of feature modeling system is improved greatly.