In a realistic oblique view of a three-dimensional surface, viewing azimuth is more important than vertical scale or elevation angle as a determinant of surface blocking. Because coordinate axes cannot easily be rotated before interpolation, some mapping software packages, in particular the SYMAP-SYMVU combination, discourage the selection of a viewing azimuth that might provide greater clarity than a traditional diagonal view. A simple direct search method for sampling and evaluating visibility over a wide range of azimuths is a useful and inexpensive approach to optimizing the orientation of oblique views. Complementary views from two orthogonal azimuths might be needed to enhance overall clarity for rough, irregular surfaces. Because trend slope correlates with surface visibility for smooth, regular surfaces, an azimuth in the direction of steepest ascent on the linear trend surface approximates the azimuth with maximum visibility and promotes the cartographic communication of the salient spatial trend.
|Original language||English (US)|
|Number of pages||16|
|Journal||Annals of the Association of American Geographers|
|State||Published - Jun 1978|
ASJC Scopus subject areas
- Geography, Planning and Development
- Earth-Surface Processes