Construction Of Gis-based Three-dimensional Visual Model Of The Coal Mine Tunnel

3D GIS research is the important development direction of the current GIS theory and application, but because the shortage of the existing methods of GIS tools in dealing with the Three-dimensional problem, which bring about restrictions of GIS application in the field of mining and geological, especially for simulation and expression of underground three-dimensional objects. And because mine is the real three-dimensional geographical/geological environment, in order to implement digital mine, it must be real three-dimensional digital mine, which is based on three-dimensional geological object and three-dimensional tunnel simulation. Nowadays, the research of the virtual reality technology's application in mine is not mature enough, to achieve the requirement of mine information construction, accelerate the theory research of the virtual reality technology's application in mine and the software development, for implement mine's scientific and modern management, secure mine safe and efficient produce, to improve the level of technological development of coal industry, are of great significance.This paper analyzes the three-dimensional data model which commonly used in coal mine applications at home and abroad and the corresponding three-dimensional data structure's research status, discuss three-dimensional data model and three-dimensional data structure, which fit for coal mine tunnel three-dimensional simulation. Introduced the three-dimensional tunnel model construction involved in computer graphics principles and development tools, design 3D model framework, discuss the whole process of image rendering, of them related to the model loading, geometric transformation, surface and digital conversion, the establishment of planar objects, vertex buffer was in-depth studied. Focus on using DirectX 9.0 technology in computer graphic design, and its application in three-dimensional tunnel model establishment. Introduced some of the necessary mathematical knowledge in 3D programming, such as the 3D coordinate system, three-dimensional space vector, matrix transformations, etc. Studied the Direct3D basic principles and some of the more advanced technology in the three-dimensional tunnel modeling establishment, including rendering of three-dimensional tunnel illumination model, and texture processing and achieve texture mapping of three-dimensional tunnel model, texture mapping is studied and implemented in the application for internal of tunnel. Discussed and implemented three dimensional tunnel mesh model technology, studied viewpoint roaming of three-dimensional coal mine tunnel, which use of camera technology, detailed analysis of the coal mine tunnel system development and design ideas and system's framework and the various functional modules, select VC++ and DirectX 9.0 as major development tools for developing 3D coal mine tunnel system, implement main functional modules, lay the foundation for implement mine three-dimensional geographic information system.