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1.3 | 
.\" RCSid $Id: genskyvec.1,v 1.2 2010/09/03 23:53:49 greg Exp $ | 
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1.1 | 
.TH GENSKYVEC 1 12/09/09 RADIANCE | 
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.SH NAME | 
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genskyvec - compute patch radiance averages for a specific sky | 
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.SH SYNOPSIS | 
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.B genskyvec | 
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[ | 
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.B "\-m N" | 
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][ | 
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.B "\-c r g b" | 
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] | 
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.SH DESCRIPTION | 
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.I Genskyvec | 
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samples the | 
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.I Radinace | 
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sky description given on the standard input to generate a list of | 
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average patch radiances. | 
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If there is a sun in the description, | 
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.I genskyvec | 
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will include its contribution in the three nearest sky patches, | 
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distributing energy according to centroid proximity. | 
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.PP | 
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By default, | 
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.I genskyvec | 
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divides the sky into 2305 patches, plus one patch for the ground. | 
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This corresponds to Reinhart's extension of the Tregenza sky, | 
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where the original 145 patches are subdivided into 16 subpatches, | 
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except at the zenith. | 
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A different subdivision may be specified via the | 
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.I \-m | 
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option. | 
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The value given will be used to subdivide each dimension, so the | 
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default of 4 yields almost 16 times as many patches | 
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as the original Tregenza sky, which can be specified with | 
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.I "\-m 1." | 
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A higher resolution sky is generally better for daylight | 
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coefficient analysis where solar position is important. | 
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.PP | 
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The | 
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.I \-c | 
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option may be used to specify a color for the sky. | 
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The gray value should equal 1 for proper energy balance | 
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The default sky color is | 
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.I "\-c 0.960 1.004 1.118". | 
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.SH EXAMPLE | 
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To generate 578 patches corresponding to a 2x2 subdivision of the | 
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Tregenza sky on a sunny equinox noon: | 
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.IP "" .2i | 
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gensky 9 21 12 | genskyvec -m 2 > sky09_21_12.dat | 
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.SH AUTHOR | 
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Greg Ward | 
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.SH "SEE ALSO" | 
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greg | 
1.3 | 
dctimestep(1), genBSDF(1), gensky(1), gentregvec(1), rcontrib(1), rtrace(1) |