Model Abstraction Techniques for Virtual Prototyping

The incorporation of VR (virtual reality) technology in the CAD/CAM community shows a promising future. Virtual prototyping uses VR techniques to simulate various functionalities of a candidate design. Downstream aspects of the product can be examined early at the design stage, saving the time and money required for repetitive design iterations. Real-time rendering is essential for interactive VR applications. This is especially challenging when dealing with complex geometric databases. Various methods have been proposed in the literature to tackle this problem. Level-of-details is a methodology that incorporates multiple representations of a model in the viewing environment. It reduces the rendering load by presenting the model in the most appropriate level of detail. However, these simplified representations often require laborious redesign efforts. In this paper, several model simplification techniques are reviewed. An automatic simplification procedure for CSG models is also devised. This method incorporates both the geometric simplification and the dimensional reduction schemes. Implemented on a non-manifold topological kernel, the system has been shown to produce promising results.