NAME

       genklemsamp - generate ray samples over surfaces using Klems BSDF basis

SYNOPSIS

       genklemsamp [ -c N ][ -f{a|f|d} ] [ view opts ] [ geom.rad ..  ]

DESCRIPTION

       Genklemsamp  generates  ray origins and directions to sample planar surfaces needed to determine incident
       radiances or daylight coefficients.  This command is typically used in conjunction with  rtcontrib(1)  to
       analyze exterior daylight coefficients for an annual simulation.

       The  view  options  are  needed  to  specify  (at  minimum)  the view direction, which corresponds to the
       orientation of the surfaces, and the view up vector, which corresponds to the azimuth=90-degree  position
       on the Klems sampling hemisphere.  The view fore clipping distance is also quite useful, as it provides a
       means  to  pass  through some thickness in a fenestration system before samples are sent out.  Other view
       options such as the view type and aft clipping distance are overridden or ignored.

       If no Radiance scene files are provided, then the specified parallel  view  defines  the  width,  height,
       center,  and orientation of the window or facade of interest.  If one or more scene files are given, they
       are presumed to contain planar surfaces over which  genklemsamp  will  originate  samples.   The  sampled
       surface  normals  must  correspond  to  the specified view direction, and unaligned surfaces are silently
       ignored.

       The -c option specifies the number of rays  to  sample  per  Klems  direction.   These  samples  will  be
       distributed evenly over the surface(s).  The default setting is 1000.

       The  -ff  option specifies that output rays should be generated as 32-bit IEEE binary float values.  This
       may be more efficient if passed directly to rtcontrib or rtrace(1) with the same option.   Likewise,  the
       -fd  option  specifies  64-bit  IEEE  binary  double  values.   The default setting of -fa produces ASCII
       floating point values.

EXAMPLE

       To generate 500 samples per direction over a set of south-facing windows and pass to rtcontrib to compute
       daylight coefficients in a matrix:

         genklemsamp -c 500 -vd 0 -1 0 -vu 0 0 1 south_windows.rad | rtcontrib -c 500 -e MF:1 -f reinhart.cal -b
         rbin -bn Nrbins exterior.oct > Dsouth.dat

AUTHOR

       Greg Ward

SEE ALSO

       dctimestep(1), genBSDF(1), genskyvec(1), mkillum(1), rtcontrib(1), rtrace(1), vwrays(1)

RADIANCE                                             6/13/09                                      GENKLEMSAMP(1)