Parser And Interactive Technique Research Of Internet-Oriented Virtual Facility Description Model

With the progress in network technology and application of in-depth, more virtual stadiums are required to be expressed by network. Therefore, the research of modeling virtual stadiums and parser technology has a wide range of practical. The parser extracts information from the text description of documents, and translates the flat text format description document into virtual stadiums and displays it in the browser. The parser can also append interaction modules and support users to interactive with the three-dimensional stadiums in the Web environment. Virtual stadiums scene paser is closely related to modeling language. As a new type of virtual reality modeling language, X-VRML has enormous advantages and wide application prospect. The purpose of the research is to quest the X-VRML paser theory of description document and interactive methods.First, this paper carries out in-depth reseach with the document structure and grammar of X-VRML, and an X-VRML parser prototype structure is proposed on this basis. Tree-level information parser technology is applied. Java and Java3D graphics engine is used to achieve the resolve of the X-VRML virtual stadiums description documents. In order to enhance the efficiency of the paser, the optimization algorithm which delayed start and reduced the redundancy is designed to reduce memory occupancy and processing time.Second, through the analysis of the technical features of X-VRML and Java3D, the scenes building part of the X-VRML parser is designed. Because the auxiliary library of the three-dimensional model provided by Java3D is limited, it can only achieve the simple model mapping. The using of triangles as the basic element modeling tools solves the problem effectively.Finally, this paper also makes research of the interactive technology of Virtual stadiums, and achieves the virtual stadiums visit mechanism and expands some interactive features. The method and prototype are feasible through the testing by using the practically making parser and scene describing file. It not only reduces the memory consumption and improves the efficiency of the system to resolve, it also has a better three-dimensional display and response speed and achieves the manipulation and free control of object in a complex scene.