Atmospheric illumination and shadows

ABSTRACT

The shadow volume algorithm of Frank Crow was reorganized to provide information on the regions of illuminated space in front of each visible surface. This information is used to calculate the extra intensity due to atmospheric scattering, so when the atmosphere is partly in shadow, columns of scattered light will be visible. For efficiency in sorting the shadow edges, the image is computed in polar coordinates.

References

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2. 2.Atherton, Peter, Weiler, Kevin, and Greenberg, Donald, "Polygon Shadow Generation," SIGGRAPH '78 proceedings, pp. 275-281.
3. 3.Crow, Franklin, "Shadow Algorithms for Computer Graphics," SIGGRAPH '77 proceedings, pp. 242-248.
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7. 7.Cook, Robert, Porter, Thomas, and Carpenter, Loren, "'Distributed Ray Tracing," SIGGRAPH '84 proceedings, pp. 137- 145.
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