Given a set of polyhedra and a polygon "sigma" in E3, the sigma-aspect graph is a partition of the faces of the polyhedra into regions such that the area of sigma that is visible from each region has the same structure or ``aspect.'' We present an output-sensitive algorithm to compute the sigma-aspect graph. In computer graphics, this problem arises in rendering images of polyhedral scenes illuminated by area light sources. This is the first analytical solution for the problem and the algorithm is simple enough to be useful in practice.
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@inproceedings{SG-cccg93,
author = "A. James Stewart and Sherif Ghali",
title = "An output sensitive algorithm for the computation of shadow boundaries",
booktitle = "Fifth Canadian Conference on Computational Geometry",
year = "1993",
month = "August",
pages = "291--296"
}