Study On The Road 3D Visualization Based On Digital Elevation Model

If designer can observe the road virtual 3D environment during the design process of the road, this can be utilized to estimate route alignment, the coordination of road and landscape in around of the road, and so on, it is no doubt that will be great beneficial to optimize road location and to improve design quality . Then road 3D visualization emerged, The design of road visualization can not do without 3D terrain.We should establish Digital Elevation Model for designing 3D-road based on the 3D terrain, achieve the original terrain data that would be used in establishing a digital elevation model after analysis the topographic map documents, establishing Digital Elevation Model utilizing VC language with the support of OpenGL, the procedures establishing 3d-road on Digital Elevation Model automaticly according to the data that be importated by users, finishing the full-scene dynamic perspective view.The chief research contents and achievements can be summarized as follows : (1) Data acquisition , analysising the the file of DXF and access the data of terrain; (2) Data structure of DEM design , based on the Delaunay triangulation theory , constructing Triangulated Irregular Network based on the incremental insertion algorithm and Recursion Local Optimization Procedure, then draw the 3D-terrain utilizing the OpenGL; (3) Construction the 3D-road,the user can insert data of road, then access the 3D-data of the road by calculation according to the data that has already exist , then draw and play up with the support of OpenGL, establishing the 3D-road based on the 3D-terrain; (4) With the support of OpenGL double buffer, projection, mode conversion, illumination and material, based on the 3D observation theory , the paper develops a Animation class which not only can give the 3D observation orders such as clicking, narrowing, rotating, translation etc , but also obtain the view parameters such as the viewpoint location, the direction of view etc, draw DEM and 3D-road , finishing the full-scene dynamic perspective view.Through the creation of digital elevation models we could do 3D analysis, simulation of a continuous distribution of the terrain, can provide a scientific and effective method for three-dimensional terrain and road design.