Tools for Digital Cliff Drawing
Summary
In 1995, a method to generate digital cliff drawings for mountain maps has been proposed. The algorithm is based on the so-called ridge line representation as proposed for instance by Imhof. Only upper and lower borderlines and vertical form lines are represented. Their thickness, and curvature is calculated according to an illumination model. A hachure to fill the spaces between those lines is suppressed. In the meantime the method has been applied in three mapping projects: In a map of a Greek volcanic peninsula, 1100 cliff objects had to be drawn. For a large mapping project on the Arab peninsula, the method has also been used. In two other projects in the Austrian Alps and on Mt. Rainier, the usability of digital cliff hachure for large walls of rock has been examined.
In 2000 began the developement of a method to generate fill hachures. The main purpose is to draw hachures in the manner of the cliff representation of Swiss Federal Office of Topography (swisstopo). The hachures are drawn in a half automatic way. However it is still time consuming and difficult to paint hachures. A first test of this program was made with Mount Bristen.
Project period
08.04.2002 – ?
Researchers
Lead: Hurni, Lorenz
Internal: Dahinden, Tobias Clemens. Hutzler, Ernst.
External: Gilgen, Jürg (Federal Office of Topography swisstopo)
Funding source
Own resources of the professorship
Partner
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Web
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Publications
Dahinden, T. 2003. Existing Cliff Representations in Topographic Maps and their Ability to be Generated Digitally. Proceedings of 2002 ICA Mountain CartographyWorkshop, http://www.karto.ethz.ch/icacmc/
mt_hood/proceedings.html, 20 S..
Dahinden, T.; Häberling, Ch.; Jenny, B.; Neumann, A.; Räber, St.; Hurni, L. 2003-12-31. Dritter ICA Mountain Cartography Workshop vom 15.-19. Mai 2002 am Mount Hood, Oregon, USA. Kartographische Nachrichten, (1/ 54), Bonn, Kirschbaum-Verlag, 32-34
Dahinden, T.; Häberling, Ch.; Jenny, B.; Räber, S.; Hurni, L. 2003. Mountain Cartography – 3rd ICA Mountain Cartography Workshop. ICA News, (41), Perth, Australia, International Cartographic Association.
Hurni, L.; Dahinden, T.; Hutzler E. 2003. Digital Cliff Drawing for Topographic Maps "U Traditional Representations by Means of New Technologies. Cartographica, 38 (1/2), 55-65.
Hurni, Lorenz; Jenny, Bernhard; Dahinden, Tobias; Hutzler, Ernst. 2001. Interactive Analytical Shading and Cliff Drawing: Advances in Digital Relief Presentation for Topographic Mountain Maps. Proceedings of the 20th International Cartographic Conference, ICC 2001 Bejing, ICC, Beijing.