面向虚拟制造的多细节层次模型研究

AbstractTo keep up with the rapidly shifting market and reduce production cost and time,manufacturing enterprises introduce many advanced technology into design andmanufacturing area.Virtual manufacturing is the inevitable result of the development ofadvanced manufacturing technology,and it becomes one of the focuses in the research areaof advanced manufacturing technology.The requirements for technique of virtual realitywith the rapid development of virtual manufacturing increase steadily.As a key technique ofvirtual reality,3D graphics real-time rendering technique affects the progress of virtualmanufacturing technique in a considerable degree.In this paper,the mesh simplification ofmultiple level of detail,one of real-time rendering techniques,is studied andimplemented.First of all,based on the systematic reading of the relative literatures,the general theoryof real-time rendering technique is introduced.The background,current state of art,thefuture trend,the purpose and significance of this research are reviewed,and then the theoriesand 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 visualacuteness and four criterions for simplification of mesh model.This algorithm can simplifythe meshes of the scene drastically and accelerate rendering speed.Furthermore,the meshmodel 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 ofdifferent modules are described in detail.This system will benefit for the development ofrelative systems which have the value of practical application.Finally,all work of the thesis is summarized,and the problems that need to be solved inthe future are also pointed out.Key Words:virtual manufacturinglevel of detail (LoD)mesh simplificationview-dependentoctree