Research On Multiple Levels Of Detail For Virtual Manufacturing

To keep up with the rapidly shifting market and reduce production cost and time, manufacturing enterprises introduce many advanced technology into design and manufacturing area. Virtual manufacturing is the inevitable result of the development of advanced manufacturing technology, and it becomes one of the focuses in the research area of advanced manufacturing technology. The requirements for technique of virtual reality with the rapid development of virtual manufacturing increase steadily. As a key technique of virtual reality, 3D graphics real-time rendering technique affects the progress of virtual manufacturing technique in a considerable degree. In this paper, the mesh simplification of multiple level of detail, one of real-time rendering techniques, is studied and implemented. First of all, based on the systematic reading of the relative literatures, the general theory of real-time rendering technique is introduced. The background, current state of art, the future trend, the purpose and significance of this research are reviewed, and then the theories and techniques of the relative algorithm of mesh simplification are summarized. Secondly, based on the relative theory of 3D graphics rendering algorithm, a view-dependent simplification algorithm of mesh model is proposed,which combining visual acuteness and four criterions for simplification of mesh model. This algorithm can simplify the meshes of the scene drastically and accelerate rendering speed. Furthermore, the mesh model of scene is built by using spatial octree and a z-buffer hidden algorithm is put forward. Thirdly, a prototyping system for the quick rendering of workshop scene is developed. The general structure of the system is designed in modules; the functions and realization of different modules are described in detail. This system will benefit for the development of relative systems which have the value of practical application. Finally, all work of the thesis is summarized, and the problems that need to be solved in the future are also pointed out.