Engineering Approach of Overlaying Railway Line onto Digital Terrain Model

A new method for creating three-dimensional overall terrain and railway line model is presented．Digi-tal Elevation Model with quadrangular meshes is taken as the terrain background．Cross section lines of railway roadbed are overlaid onto DEM，and their intersection points with DEMmeshes are used as new inserted nodes to generate local triangular meshes．Such an approach is simple to realize and highly efficient．AutoCAD together with 3DS is used to output various presentations．