Research And Implementation Of Typical Layer Visualization Of 3D Geospatial Data

With the development of 3D GIS, the urgent requirements of" Digital Earth ",3D visualization has become an important research direction, the massive, multiple sources, multi-dimensional and complex visualization of data and analysis is becoming increasingly problem, so this paper study on 3D visualization of geo-spatial data about typical layers.The main innovations of this paper are:(1)Implementing the processing of large scale image based on GLSL (shading language),the expansion of elevation and contour map based on GLSL,improving the efficiency of rendering.(2)Implementing the control of 3D model based on OpenGL.(3) Developing layer Manager based on QML and C++.Main contents of this paper are:(1) Implementing terrain visualization with the LOD (level of detail) technology, researching and implementing the processing of large scale image based on GLSL, the expansion of elevation and contour map based on GLSL.(2) Using 3ds Max as a modeling tool, delimiting XML file and loading model into the 3D scene, implementing the visualization of 3D city. Implementing the control of 3D model based on OpenGL, including zoom, rotation, translation, and pick.(3) Studying two scene effects about weather and stars.Using particle system to simulate rain and snow, rendering the rain and snow based on OpenGL. Implementing fog effect using GLSL defined in GPU, which improve the efficiency of rendering, making the rendering more flexible. Simulating star effect based on OpenGL.(4) Studying the engine and system’s modules about analytical and visualized platform with geographic information, designing the layer Manager based on need of platform. Analyzing the objectives, proposing the framework and ideas in designing layer Manager, developing layer Manager based on QML and C++.Studying 3D visualization of geo-spatial image, elevation, models, scene effects, applied to the analytical and visualized platform with geographic information, implementing the basis functions of the platform. Layer Manager is designed so that the whole platform can manage layers effectively and easily.