3D vs. Conventional Volcanic Hazard MapsCharles Preppernau, Oregon State University Bernhard Jenny, Oregon State UniversityVolcanic hazard maps are used as public outreach and education tools, but can be challenging for those not trained in map use or geology. We present the results of a user study evaluating the relative effectiveness of four map designs in showing the speed and extent of lahars, a dangerous, fast, and relatively lesser-known volcanic hazard. The study tested combinations of two binary design variables; 2D contours vs. 3D perspective for terrain representation, and point markers vs. isochrones for lahar travel time. We found that users preferred and performed best with the 3D isochrone map.
https://speakerdeck.com/nvkelso/3d-vs-conventional-volcanic-hazard-mapsEvaluating the Effectiveness of Illuminated and Shadowed Contour LinesJames Eynard, Oregon State University Bernhard Jenny, Oregon State UniversityThe effectiveness of illuminated contour lines, where line width and color vary based on an angle of illumination, has not been fully examined as compared to conventional contour lines. Illuminated contour lines are not widely used in computer-based cartography because they are not included in most GIS and mapmaking software. Improvements to existing algorithms for creating illuminated and shadowed contour lines from digital elevation data are presented. A software package is made available to allow mapmakers to more easily make customized illuminated contour maps. A user study comparing illuminated contour lines to other relief representation techniques with 400 participants was conducted. The results indicate that map-readers can interpret relative height differences between points better and quicker with illuminated contour lines than regular contour lines or shaded relief. These findings suggest that illuminated contour lines could be used more frequently for improved visualization of terrain and other surface data on maps.
https://speakerdeck.com/nvkelso/evaluating-the-effectiveness-of-illuminated-and-shadowed-contour-linesPlanning a Hike with Fifty Shades of GrayLeland Brown, textureshading.comElevation contours can be depicted using stepwise hypsometric tinting or shading, but the human eye can only perceive a limited number of separate shades on a map. By mimicking an optical illusion called the Mach effect, we can generate the appearance of hundreds of graduated shades of gray, each clearly distinguishable. Using a high-resolution LiDAR-derived elevation model, this visualization technique helped me to plan a safe off-trail hiking route through extremely rugged wilderness in the southern California mountains. Example images will be presented, along with photos of the actual hike.
https://speakerdeck.com/nvkelso/planning-a-hike-with-fifty-shades-of-grayImproving the Representation of Major Landforms in Analytical Relief ShadingBrooke E. Marston, Oregon State University Bernhard Jenny, Oregon State UniversityManual relief shading results in informative and visually pleasing representations of terrain, but it is time consuming and expensive to produce. Current analytical relief shading can be created quickly, but the resulting maps are not as aesthetically appealing and do not show landscape features in an explicit manner. This project introduces an automated digital method that produces shaded relief with locally adjusted illumination directions to simulate the techniques and cartographic principles of manual relief shading. Ridgelines and valley lines are derived from a digital terrain model and used in a diffusion curve algorithm. The direction of illumination is adjusted based on the spatial orientation of ridgelines and valley lines. The diffusion curve shading is combined with standard analytical relief shading to create a final diffusion relief shading. Similar to manual relief shading, major landforms and terrain structure are more clearly shown in the diffusion relief shading.
https://speakerdeck.com/nvkelso/improving-the-representation-of-major-landforms-in-analytical-relief-shading
