Introducing plan oblique relief

Plan oblique relief is a new digital technique for rendering three-dimensional terrain on otherwise planimetric (conventional flat) maps. Landforms shown realistically in side view have an illustrative quality that appeals to readers. Inspired by the work of manual mapmakers of the past, the paper begins with a historical review that includes maps by Xaver Imfeld of Switzerland, Erwin Raisz of the United States, and Heinrich Berann of Austria. In the next, digital techniques section, the projections and rendering parameters needed to create plan oblique relief receive attention, as does Natural Scene Designer 5.0, the first commercial software to offer this functionality. The section on design takes a candid look at the advantages and disadvantages of plan oblique relief. The paper ends on a practical note by discussing two maps made by the authors that feature plan oblique relief, one a panorama and the other a physical map.