The Research And Implementation Of Terrain 3D Visualization In Heihe River Basin Based On Skyline

With the rapid development of science and technology,3D geographical information system attracts much concern in various fields for its intuition, having a broad space for development and application prospects, becoming the main trend of geographic information system (GIS) research and development. The terrain 3D visualization is one of the key technologies to establish 3D GIS.The theory technology research and practice are used together to construct the terrain 3D visualization system of Heihe River Basin in this paper. It is mainly concern as follows in this paper:(1) The basic theory and technology of terrain 3D visualization is introduced in this paper, pointing out that the 3D modeling and surface texture mapping technology is the important step to construct terrain 3D visualization. The main three models of the digital elevation model (DEM): contour model, regular grid model and TIN (Triangulated Irregular Network) model are compared with every model's basic theory and advantages & disadvantages. Considering the Heihe River Basin having a vast territory and complicated terrain triangulated irregular network modela with a simple data structure and directly modeling methods is proper to construct 3D terrain in this paper. The principle of surface texture mapping and the technology of a variety of texture mapping are expounded, pointing out that the "whole quality is low, local quality is high "strategy is used to organize the surface texture data.(2) Based on a thorough analysis of the necessity and feasibility of the Heihe River Basin terrain 3D visualization system, the overall structure design, function module partition, database design and interface design of the Heihe River Basin terrain 3D visualization system terrain are finished.(3) The premise condition for data organization to establish terrain 3D visualization system is proposed from the spatial reference datum and data formats while the spatial data organization mode is summarized from terrain data, the earth's surface model data and two-dimensional vector data.(4) Based on the superiority and structure and function of Skyline software, efficient methods and processes to establish 3D scene are summed up.(5) With Visual Studio 2005 as programming environment and Skyline TerraExplorer API & ArcGIS Engine as interface the Heihe River Basin visualization system is achieved.The Heihe River Basin terrain 3D visualization system designed by this paper can be used for displaying 3D scene of Heihe River Basin terrain, spatial analysis based on 3D environment, information query and so on. It can also be used to study the arid oasis transformation and environmental evolution, especially useful to provide a good show of oasis spatial pattern evolution with large scale and long processes.