Virtual Forest 3d Visualization

3D virtual forest scene is a key technology in forestry informatization,construction of 3D virtual forest scene is an important step to realize digital forestry and modern forest management, consistent with prevailing international modern forestry management and research methods. It is significant for forest landscape planning, policy-making and forest knowledge teaching.In this thesis, three-dimensional visualization of virtual forest scene is studied. Based on advanced technology about 3D computer graphics, virtual reality, fractal geometry theory, technique of terrain fractal simulation, terrain LOD technique, 3D graphic engine and scene realization are discussed. Finally, a basic 3D graphics engine is designed with object-oriented technology. Based on the engine, hereby, a system of virtual forest scene visualization is realized.The main work of this thesis includes:1. Utilized random midpoint displacement method to generate the terrain height map with the terrain generation technology to build a digital terrain model.2. Studied Real-time rendering of Large-scale terrain scene, and introduced an improved rendering method of multi-resolution terrain model based on GeoMipMapping method; Such algorithm simplified the creation of multi-resolution terrain mesh by using an index buffer sequence residing in video memory, and speeded up the sketch of the scenes to represent terrain blocks'detail levels, and realized geometric transition and gap erasing.3. Studied the special effect techniques to render sky, sun light, trees and other objects to enhance the environment feeling of the forest scenes.4. With the technique of object-oriented the engine frame of 3D graphics was constructed, and primarily realized three kernel modules of the engine, namely, scene management, resource management and render system.5. According to the ideas and techniques mentioned above, a virtual forest 3D graphic system was developed, consequently verified the correctness of the conceiving and feasibility of techniques of virtual 3D forest scene visualization.