Abstract: Embodiments of the invention provide a method for creating a complete 3D model of complex infrastructure configurations, such as divided highways, roadway intersections, etc. Current CAD applications have been limited to creating 3D models based on the geometry of a single alignment. In one embodiment, each baseline for a 3D model using four data inputs: a topographical terrain model, an alignment specifying the longitudinal 2D geometry for the structure being modeled, a profile specifying the elevations of the baseline along the horizontal alignment, and the geometry for cross-sectional assemblies along the horizontal and vertical alignments.

Abstract: A method, apparatus, and article of manufacture provide the ability to update a drawing surface in a CAD/GIS computer application. First, a drawing surface is displayed in a CAD/GIS application. A surface edit operation is then performed on the drawing surface. The CAD/GIS application then determines if an automatic rebuild option is active. If the rebuild option is active, the drawing surface is dynamically and automatically rebuilt to reflect the surface edit operation. Alternatively, if the automatic rebuild option is inactive (e.g., toggled off), the drawing surface is flagged as out-of-date.