Cartographic Relief Presentation

Swiss-style rock drawing uses shaded hachures to show the characteristic forms and the third dimension of rocks and cliffs. Rock faces, trenches, gullies, faults and other rock features relevant for orientation and navigation in mountainous areas are shown as seen from the ground instead of from an orthogonal perspective. The density and dimensions of hachures change with the exposure to a source of illumination to generate a shading effect that highlights the terrain’s three-dimensionality. The generation of rock drawings in Swiss style is time-intensive and requires an eye for the artistic rendering of the terrain’s third dimension as well as an understanding of different rock types and their morphology. Design principles have not yet been documented in a detailed and comprehensive manner and only rudimentary algorithms exist for the digital generation of simplified representations. This paper discusses the defining characteristics and specific design principles of Swiss-style rock drawing based...

Design principles for Swiss-style rock drawing

Graphic interfaces of geoportals allow visualizing and overlaying various (visually) heterogeneous geographical data, often by image blending: vector data, maps, aerial imagery, Digital Terrain Model, etc. Map design and geo-visualization may benefit from methods and tools to hybrid, i.e. visually integrate, heterogeneous geographical data and cartographic representations. In this paper, we aim at designing continuous hybrid visualizations between ortho-imagery and symbolized vector data, in order to control a particular visual property, i.e. the photo-realism perception. The natural appearance (colors, textures) and various texture effects are used to drive the control the photo-realism level of the visualization: color and texture interpolation blocks have been developed. We present a global design method that allows to manipulate the behavior of those interpolation blocks on each type of geographical layer, in various ways, in order to provide various cartographic continua.

Cartographic continuum rendering based on color and texture interpolation to enhance photo-realism perception

Designing maps involves numerous decisions on the part of the cartographer, while designing terrain maps adds unique complexities. Terrain is often conceptualized as varying in a smooth and continuous manner, leading to data being stored with field-based models, often using raster datasets. The focus of many map design books and other literature, however, is on symbolizing object-based models. Vector layers such as contours and hachures can be derived from grids, but are conceptually abstract and require special consideration for three-dimensional display. We propose a classification scheme for terrain maps based on four principal elements of design: layer tinting, shading, texturing and form lines. We also propose a new method for automating horizontal hachures that illustrates how the latter three elements meet at a critical design juncture where location, orientation, derived attributes and the use of visual variables to symbolize the terrain intersect. Horizontal hachures combine multiple desi...

Complexities of designing terrain maps illustrated with horizontal hachures

Supplementary contour lines are placed between regular contour lines to visualize small but important forms that regular contour lines are unable to show. On topographic maps, typical forms are hil...

Automated placement of supplementary contour lines

This paper explains how rock representations are drawn in vector and raster mode at the Federal Office of Topography swisstopo, the National Mapping Agency of Switzerland. The drawing efficiency is compared of both LorikCartographer by Lorienne, a cartographic application for drawing in vector mode, and the raster graphics application Photoshop by Adobe. Additionally, Scree Painter is introduced, a specialized complementary application for the automatic drawing of scree representations.

http://www.mountaincartography.org/publications/papers/papers_borsa_10/05_gilgen.pdf

Digital rock and scree drawing in vector and raster mode

In manchen hochalpinen Gebieten sind Gerollfelder ein dominierendes Landschaftselement und werden deshalb auch in topographischen Karten dargestellt. Die Grose und die Dichte der kleinen Punktsignaturen variieren mit der Exposition zu einer gedachten Lichtquelle, und die Grose der Punkte andert sich mit der relativen Lage in Gebirgshangen. Die Punkte werden zum Teil in Linien angeordnet, um die Fallrichtung des Gerolls anzuzeigen. Die Erstellung von Gerollsignaturen fur grosere Flachen ist deshalb ohne spezialisierte digitale Unterstutzung sehr arbeitsaufwendig. In diesem Artikel wird ein neues automatisches Verfahren vorgestellt, mit dem Gerollfelder mit minimalem Aufwand symbolisiert werden konnen. Dabei werden zuerst die Gestaltungsprinzipien zur Gerolldarstellung identifiziert, wie sie vom Bundesamt fur Landestopografie swisstopo angewendet werden; dann wird die digitale Methode vorgestellt und schlieslich wird Scree Painter eingefuhrt, eine spezialisierte freie und quelloffene Software.

Automatische Gerölldarstellung für topographische Karten

The maps of the Federal Office of Topography swisstopo - the Swiss national mapping agency - are renowned for their combination of shaded relief, contour lines, scree rendering and rock drawing, which creates the so-called Swiss style of topographic mapping. During the era of analogue map production, rock drawing was executed with scribing on coated glass plates. With the ongoing computerization of cartography, swisstopo switched to a digital production line a few years ago. However, high-quality Swissstyle rock drawing for topographic maps is still a very labor-intensive process. At swisstopo, revisions to rock representations are carried out using interactive mouse-based drawing tools, as automated procedures do not currently exist. The Federal Office of Topography swisstopo and the Institute of Cartography of ETH Zurich therefore carry out a joint study to evaluate the potential of digital techniques for automating rock drawing. The first step of this project is a detailed study of the current manually drawn rock depiction, including design principles and geometric dimensions. This paper discusses current mousebased drawing techniques applied by swisstopo for their official map series and then shortly describes the graphical design principles for Swiss-style rock drawing. Metrics for individual rock hachures are included.

Jürg Gilgen

Papers

Design principles for Swiss-style rock drawing

Digital rock and scree drawing in vector and raster mode

Automatische Gerölldarstellung für topographische Karten

Rock drawing for topographic maps