Given a bounded region in a plane, we define the skiance* of a point as the area of the region that is blocked from view by a small obstacle at the point, averaged over all viewpoints in the region. The skiance is shown to be zero on the region's convex hull. The skiance can be calculated by an O(N) algorithm, where N is the number of data points defining the region's boundary. Possible applications of the concept are discussed.
* from Greek skia, a shadow.
Slides for a presentation on skiance, June 6, 2003.
An applet for interactive numerical skiance calculations.
Copyright © 2003 Ernst W. Grundke (http://www.cs.dal.ca/~grundke)
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Last updated June 8, 2003.