NAME

       genskyvec - compute patch radiance averages for a specific sky

SYNOPSIS

       genskyvec [ -m N ][ -c r g b ]

DESCRIPTION

       Genskyvec  samples  the Radinace sky description given on the standard input to generate a
       list of average patch radiances.  If there is a sun in  the  description,  genskyvec  will
       include  its  contribution in the three nearest sky patches, distributing energy according
       to centroid proximity.

       By default, genskyvec divides the sky into 2305 patches, plus one patch  for  the  ground.
       This  corresponds  to  Reinhart's  extension  of  the Tregenza sky, where the original 145
       patches are subdivided into 16 subpatches, except at the zenith.  A different  subdivision
       may  be  specified  via  the  -m  option.   The value given will be used to subdivide each
       dimension, so the default of 4 yields almost 16 times as  many  patches  as  the  original
       Tregenza  sky,  which  can  be  specified with -m 1.  A higher resolution sky is generally
       better for daylight coefficient analysis where solar position is important.

       The -c option may be used to specify a color for the sky.  The gray value should  equal  1
       for proper energy balance The default sky color is -c 0.960 1.004 1.118 .

EXAMPLE

       To  generate 578 patches corresponding to a 2x2 subdivision of the Tregenza sky on a sunny
       equinox noon:

         gensky 9 21 12 | genskyvec -m 2 > sky09_21_12.dat

AUTHOR

       Greg Ward

SEE ALSO

       dctimestep(1), genBSDF(1), gensky(1), gentregvec(1), rtcontrib(1), rtrace(1)