Study On Three-dimensional Visual Modeling Of Railway Lines

In recent years, the3D geographic information system is a hot research field in GIS ofwhich the3D function is an important component. Three-dimensional GIS expresses things ina more real way and more vivid, giving people a “virtual reality feeling”. We can get somenew data and information through the function of GIS three-dimensional space analysis.Railway is the artery of communication in national economic development. Based on theconcept of digitalization, combined with geographical information tec hnology, computertechnology and graphics knowledge, using3D visualization to convey the railway lines so asto construct the platform of railway information management has become an importantdirection of the development of railway industry at present.Based on the concepts and techniques of3D GIS, the paper studies the modeling methodof three dimension terrain along the railway lines. Through analyzing and comparing thedifference between CAD data and ArcGIS data, this thesis applies ArcGIS software to processthe topographic contour data in the form of dwg, and further constructs3D terrain models inthe software of SketchUp and ArcMap respectively.According to the line coordinate data center design, this thesis generates a space centerline in the form of AutoCAD secondary development, cooperates with line horizontal andlongitudinal profile data and builds3D model of tracks railway in the SketchUp modelingsoftware. And using engineering design parameters to build3D model of line engineeringobjects and complete3D scene modeling of the railway. In the whole process of modeling, theauthor of this paper simplifies the complexity of the model and modeling process afteranalyzing the characteristics of line engineering objects and modeling process and improvesthe show efficiency of the model and shortens the modeling cycle to a certain extent.By collecting coordinate location information of the terrain along the railway, this thesispieces the terrain model and line scenarios model together through rotation, translation andstretching in SketchUp software. Further, it studies Multipatch data storage format of GISpolyhedron data model based on the whole modeling and converts SketchUp software modelinto Multipatch data, which provides3D scene data support for the later development of thesystem.ArcEngine is an advanced component of ArcGIS. Using SceneControl of ArcEngine as3D scene driving and C#as development approach, this thesis develops GIS applicationprogram with the functions of scene browse, information inquiry and3D space analysisThe system of railway line3D visualization in the present thesis provides an intuitive and3D virtual circuit scene which can understand the whole line landscape or detailedlandscape through roaming, scaling, flight, information inquiry and other functions.3Dspatial analysis function can provide certain analysis capabilities for relevant mangers andvisual platform for line management department, which has a certain practical significance forrailway information construction.