High-quality cartographic roads on high-resolution DEMs

The efficient and high quality rendering of complex road networks-given as vector data-and high-resolution digital elevation models (DEMs) poses a significant problem in 3D geographic information systems. As in paper maps, a cartographic representation of roads with rounded caps and accentuated clearly distinguishable colors is desirable. On the other hand, advances in the technology of remote sensing have led to an explosion of the size and resolution of DEMs, making the integration of cartographic roads very challenging. In this work we investigate techniques for integrating such roads into a terrain renderer capable of handling high-resolution data sets. We evaluate the suitability of existing methods for draping vector data onto DEMs, and we adapt two methods for the rendering of cartographic roads by adding analytically computed rounded caps at the ends of road segments. We compare both approaches with respect to performance and quality, and we outline application areas in which either approach is preferable.