Research On 3D Geography System Rendering

Thanks to the development of science and technology, the gathering of 3D geography information and 3D scene rendering by computer is reality nowadays. Then people's long time limited need for 3D geography system is released. Electronic 3D geography system is one of the most popular research issues. A good 3D GIS need a good 3D rendering system to draw cities, mountains and rivers, and to provide interface and foundation to the main system.A 3D rendering system is such a system that draws the massive terrain and cities on the earth based on computer graphic technology. It's main target is: good rendering effect, handling massive data well, high efficient of rendering, available through the internet. And the main problem it faces is: massive data and limited computer main memory; complicated scene for an arbitrary frame and not very powerful CPU and GPU.This paper is going to build a 3D rendering system combined by massive terrain rendering system and massive cites rendering system. First, we will research current main results in both areas to provide the system design with basic theory; then we will propose our new ideas and algorithms to improve and perfect the theory we study from the first step; at last, we will design and implement the final rendering system based on step 1 and step 2.At the end of this paper, we will discuss about the shortage of the system we have build, and a future plan of improvement and perfect will be proposed at last.