Performance-enhancing extensions to an algorithm for ray-tracing height fields are described. This work will be of interest primarily in applications to flight simulation and other terrain-based rendering systems. The specific improvement discussed in this paper considers sets of inverted cones of empty space over each height field cell, and allows the opening angles of different angular sectors of each cone-like volume to vary according to the level of neighboring obstructions. This approach results in an algorithm with improved performance in situations such as rendering detail along the bottom of an elevated ridge.

This research is built directly upon the author’s previous work, including Paglieroni and Petersen [1]. As with many papers in this journal, its value for most readers lies not in its conciseness or clarity (only readers with a specific interest in the subject will enjoy wading through the mathematical formalism), but in the detailed documentation of the work in a refereed journal.