GRADUALLY CHANGING PERSPECTIVE MAP

摘要

Display of digital maps with gradually changing perspective is provided. A perspective engine selects from among possible foreshortening ratios depending on the selected map scale. In one embodiment, the perspective engine uses a fixed perspective view corresponding to each of a fixed set of scales. In alternative embodiments, there is a continuum of scales, and parameters are specified as functions of the scale, rather than as fixed values. In general, at smaller scales - that is, more zoomed-out - the displayed perspective appears to be more flat, as though looking straight down at the map. At larger scales - more zoomed-in - the map is displayed with increasing perspective. In some embodiments, once a threshold scale is reached, continuing to zoom in does not additionally increase the perspective; similarly, once a threshold zoomed-out scale is reached, the map continues to be displayed in a two-dimensional flat appearance.