The3D Research Of Terrain And Tree Based On OpenGL

With the development of GIS technology in various fields, the platform that used in the decision and management based on GIS begins to play more and more role in forestry. From the previous studies, it is easy to see that the digital forest has been the main method to express the information of forest resource. However, compared with the2D digital forest, virtual forest which is the combination of GIS,3D visualization and computer graphics can express spatial information and attribute information more intuitive and vivid. Virtual forest provides a platform of Human-Computer Interaction. And through simplified and improved the algorithm gradually, it can grasp the situation more efficient.This paper based on MaoErShan tree farm, combined with experiment of computer graphics relevant principles, based on VC++platform,using OpenGL, a three-dimensional graphics software interface,, using Q-Tree and LOD to realize3D terrain display of MaoErShan forest field area combined with OpenGL, the3D graphics software interface, roaming and setting environment, gives simplified terrain evaluation criteria by projection size and focus, completing the operation on3D display of virtual forest, and loading trees on the terrain.In virtual forest, this paper has built3D tree based on the fractal theory and defines the main algorithm of drawing the fractal tree by IFSP. The tree model is building by monopodial branching and verticillation in the terrain. In the programme, the tree model has been added texture by real photos of leaf and trunk. Therefore, the model can express the shape of northern species, and make the system rich and vivid.In the actual production, the virtual forest has wide range of application prospects in the fields of the forest resources management and afforestation as new method. It can provide the basis effectively for production and decision of forest. And the fractal tree model enhances the working efficiency of the system greatly. The controllability of the fractal tree shape can also make the forest scene changed by different natural conditions quickly and increase the flexibility and interactivity for the3D scene.