The Modeling of 3D Color Topography Based on DEM Data for 3D Printing

The simulation of the three-dimensional image could not convey the exact three-dimensional (3D) information to people in the practical application; meanwhile 3D terrain model of the physical manufacturing encountered difficulties in mold manufacturing, such as high cost, short life and other bottlenecks. The technology of 3D printing provided a solution for the manufacture of 3D topographic map. Therefore, in this paper, the NSDTF-DEM data was built by colorful 3D model to meet the needs of 3D printing. Based on the Crust algorithm, the regional reconstruction and Delaunay tetrahedral meshing were used to reconstruct the surface of DEM point cloud data. The depth map of the 3D model was obtained by the topography projection of the 3D surface. The color assignment was carried out by using the correspondence between the depth graph gray value and the number of indexed image columns, which was designed to produce the same color texture image as the depth map. This modeling method not only improved the modeling accuracy of the 3D mesh model, but also achieved higher color accuracy.