Grouping Lod Models And Related Technologies

The frescoes of Dunhuang are precious heritages of the world. How to let more people enjoy the murals and how to preserve the art treasury are the great goals which scientists and government focus on. This thesis introduces the Dunhuang Cave as the application background, and presents an improved method to eliminate the deficiencies of the original Dunhuang Cave Virtual Tour System and overcome the shortage of its unreal immersive rendering. It realizes the digitized relic preservation and the virtual demonstration. It also gives advanced means for cave archeology and relic preserve research.Firstly, this thesis gives an introduction on the application background and the characteristics of the original system, and presents an improved method. After introducing the VR technologies, 3D digital modeling, the technique of OpenGL, the automatic generation of the LOD model, we illustrate the definition of the grouped LOD model, including the algorithms for automatic generation, texture rendering, shadow generation and rendering, and embedding methods of multimedia. Finally, we describe a real-time virtual tour rendering engine designed for this model.Under the situation where the view port is surrounded by 3D model, the rendering efficiency can be greatly improved by using the grouped LOD model and its related technologies. The resources of the system will be assigned to delicately render the part of the scene which users focus on. When this model and its technologies are applied to the Virtual Tour System of Dunhuang Cave, it can provide the details of the murals and the interface to even,' user who wants to learn the cave thoroughly.