The Key Technologies Of Three-dimensional Terrain Visualization And The System Realization Of Maoershan Forest

Terrain visualization is an intuitive graphical expression of the terrain, a basic tool for people to understand the terrain. It is widely applied in earth science, resources, environment, mapping and remote sensing, military, civil engineering and other fields. Thus, the research on terrain visualization is significantly important and has gradually deepened.This thesis systematically introduces the working principle of OpenGL and related technologies, and summarizes the basic theory of three-dimensional terrain visualization and technology; The basic theory of three-dimensional graphics display is described, from several aspects such as the type of coordinate system, the application of transformation matrix to the geometric transformation, projective transformation and the viewport transformation of three-dimensional graphics; The key technologies of three-dimensional terrain visualization technology is analyzed, including the theory of digital elevation models, the methods of building and simplifying the digital elevation model based on Regular Square Grid(RSG), as well as the light and material processing and texture mapping which could enhance the realistic of the terrain and enrich the information.On the grounds of the theory above, the real-time system of Maoershan two-dimensional and three-dimensional terrain visualization is established, applying the three-dimensional graphics standard OpenGL,based on the Windows XP system and the VC + +6.0 platform, using the Maoershan digital elevation model of Northeast Forestry University. The interface of the syetem is friendly and the operation is simple. This system could receive NSDTF the standard format of DEM, be roaming and fly automatically by a pre-set path, realize the terrain visualization with the mode of light, material, and the function of coordinate inquiring etc. Ultimately, a perfect, strongly-thematic, scalable and independent Maoershan terrain visualization system has been completed, which has actual significance in the Forest Management and investigations outside.