The railway 3D visual design plays an important role in checking the rail projects and improving the quality of railway design, because the key to implement Railway a 3D visual design is to build a 3D model of railway...The railway 3D visual design plays an important role in checking the rail projects and improving the quality of railway design, because the key to implement Railway a 3D visual design is to build a 3D model of railway line landscape. The study on the methods of building a 3D model of railway line landscape is of important academic significance and practical value. We constructed a 3D digital terrain model with aerial survey Data or manual survey data in the regional railway, utilizing plan, profile, cross section data and bridge, tunnel, railway bed data to create the 3D railway line model and merging the two models to form a 3D model of railway line landscape. Based on analyzing the algorithms of Delaunay triangulation creation in Domestic and abroad, in view of the situation of building DTM and the need of realizing railway 3D visual design, a divide and conquer algorithm of building DTM is presented. The algorithm uses square grids to manage disordered points, to form triangular meshes in grids, DTM can be obtained by merging the triangular meshes so that the work of sorting the disordered points before building DTM is reduced greatly; moreover, the algorithm utilizes sub area to control the vertices of convex hull so that the range can be predefined when searching support points, the workload of searching support points reduced and the speed of merging two triangulations raised. A method for inserting constrained boundaries in DTM based on the study of the generation of constrained Delaunay triangulation is presented. First, we searched for the diagonals not intersecting with the constrained boundaries. Then we used them to cut the influenced area. The method has the advantages of a plain principle and a fast speed. The method of utilizing plan, profile, cross section data and digital terrain model to establish the 3D model of the main construction of railway line and the terrain model is presented. It describes the irregular entity surfaces by cutting them into regular entity surfaces, so that it would be si展开更多
文摘The railway 3D visual design plays an important role in checking the rail projects and improving the quality of railway design, because the key to implement Railway a 3D visual design is to build a 3D model of railway line landscape. The study on the methods of building a 3D model of railway line landscape is of important academic significance and practical value. We constructed a 3D digital terrain model with aerial survey Data or manual survey data in the regional railway, utilizing plan, profile, cross section data and bridge, tunnel, railway bed data to create the 3D railway line model and merging the two models to form a 3D model of railway line landscape. Based on analyzing the algorithms of Delaunay triangulation creation in Domestic and abroad, in view of the situation of building DTM and the need of realizing railway 3D visual design, a divide and conquer algorithm of building DTM is presented. The algorithm uses square grids to manage disordered points, to form triangular meshes in grids, DTM can be obtained by merging the triangular meshes so that the work of sorting the disordered points before building DTM is reduced greatly; moreover, the algorithm utilizes sub area to control the vertices of convex hull so that the range can be predefined when searching support points, the workload of searching support points reduced and the speed of merging two triangulations raised. A method for inserting constrained boundaries in DTM based on the study of the generation of constrained Delaunay triangulation is presented. First, we searched for the diagonals not intersecting with the constrained boundaries. Then we used them to cut the influenced area. The method has the advantages of a plain principle and a fast speed. The method of utilizing plan, profile, cross section data and digital terrain model to establish the 3D model of the main construction of railway line and the terrain model is presented. It describes the irregular entity surfaces by cutting them into regular entity surfaces, so that it would be si
