Research And Implementation Of The Digital Railway Plan System

In pasted decade,the design method mainly using CAD has holden a prominent place in plan field. It is difficult to evaluate design result without the tri-dimensional visualization,which is generally evaluated by experts' intuition and experience. Especially,CAD is difficult to achieve prospective tri-dimensional effect in the railway surveying and design. It becomes possible that digital railway plan be used,which based on 3D terrain environment for the introduction of virtual reality and the wide application of digital photogrammetric survey.In this paper,the method of applying VR,GIS,and RS techniques into plan field is discussed,which is combined with actual project. The design aim of digital railway plan system is put forward in paper. Especially it stresses the method of modeling 3D terrain landscape using DEM & digital remote sensing image based on OpenGL and the implementation of vector image subsystem for planning and editing railway line. Based all above,the digital railway plan system is developed. The system can do some operations including alternant planning the railway in the 3D terrain landscape,3D modeling,budgeting the count of evolution,querying the information of the railway,outputting of AVI. In the process of developing the system,the paper discusses in-depth some key technologies such as spatial index of triangulated irregular network (TIN) data,the integration of multi-source data,the process of DEM & texture data,the application of LOD in real-time animation,the technique of clipping in 3D landscape,the stereo synchronization,the multithreading.The railway plan,survey technology and visual reality technology are combined by digital railway plan system,which improves railway plan efficiency,shorts engineering plan periods and leads important societal and economic benefit. The appearance of digital railway plan system indicates the reformation of railway plan technology.