GENSKYVEC(1)						      General Commands Manual						      GENSKYVEC(1)

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 spec-
       ified  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  coeffi-
       cient 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)

RADIANCE
							     12/09/09							      GENSKYVEC(1)