Terrain rendering is used in a broad range of applications, such as simulations, games, education, and virtual reality. Besides commercial programs, there are, fortunately, many noncommercial open-source solutions available for terrain visualization.

The main problem associated with the rendering of high-resolution large terrains is the large amount of polygons involved. In the last few years, many level of detail (LOD) terrain algorithms have been proposed in the literature to control rendering performance. This paper presents the extension of an open-source solution for the stereoscopic visualization of terrains (Walkabout, from Electronic Visualization Laboratory, University of Illinois, Chicago). The authors provide the software with two enhancements: the direct loading of digital elevation model (DEM) files, and the implementation of a quadtree-based LOD algorithm for height fields, proposed by Thatcher Ulrich.

Just a very short overview of the implementation is presented, but the main contribution of this work is the enrichment of open-source code that can be downloaded from the Internet. This example shows the benefits of open-source software, allowing the community to contribute to create better solutions for a problem.