IES2RAD(1)						      General Commands Manual							IES2RAD(1)

NAME

       ies2rad - convert IES luminaire data to RADIANCE description

SYNOPSIS

       ies2rad [ options ] [ input ..  ]

DESCRIPTION

       Ies2rad	converts one or more IES luminaire data files to the equivalent RADIANCE scene description.  The light source geometry will always
       be centered at the origin aimed in the negative Z direction, with the 0 degree plane along the X axis.  (Note,  this  means  that  the  IES
       "width" is actually along the Y axis, while "length" corresponds to the X axis.)  Usually, two output files will be created for every input
       file, one scene file (with a ".rad" suffix) and one data file (with a ".dat" suffix).  If the IES  input  file  includes  tilt  data,  then
       another	data  file  will be created (with a "+.dat" suffix).  If the -s option is used, the scene data will be sent to the standard output
       instead of being written to a file.  Since the data file does not change with other options to ies2rad, this is a convenient way to specify
       different  lamp	colors and multipliers inline in a scene description.  If the -g option is used, then an octree file will be created (with
       the ".oct" suffix).  The root portion of the output file names will be the same as the corresponding input file, unless the  -o	option	is
       used.   The output files will be created in the current directory (no matter which directory the input files came from) unless the -l or -p
       options are used.

       Ies2rad assigns light source colors based on information in a lamp lookup table.  Since most lamps are  distinctly  colored,  it  is  often
       desirable to override this lookup procedure and use a neutral value that will produced color-balanced renderings.  In general, it is impor-
       tant to consider lamp color when an odd assortment of fixture types is being used to illuminate the  same  scene,  and  the  rendering  can
       always be balanced by pfilt(1) to a specific white value later.

       -l libdir Set  the  library  directory  path  to libdir.  This is where all relative pathnames will begin for output file names.  For light
		 sources that will be used by many people, this should be set to some central location included in the RAYPATH	environment  vari-
		 able.	The default is the current working directory.

       -p prefdir
		 Set  the  library subdirectory path to prefdir.  This is the subdirectory from the library where all output files will be placed.
		 It is often most convenient to use a subdirectory for the storage of light sources, since there tend to be many files and placing
		 them all in one directory is very messy.  The default value is the empty string.

       -o outname
		 Set  the output file name root to outname.  This overrides the default output file name root which is the same as the input file.
		 This option may be used for only one input file, and is required when reading data from the standard input.

       -s	 Send the scene information to the standard output rather than a separate file.  This is appropriate  when  calling  ies2rad  from
		 within a scene description via an inline command.  The data file(s) will still be written based on the output file name root, but
		 since this information is unaffected by command line options, it is safe to have multiple invocations of ies2rad using  the  same
		 input file and different output options.  The -s option may be used for only one input file.

       -dunits	 Output  dimensions  are  in  units,  which  is  one of the letters 'm', 'c', 'f', or 'i' for meters, centimeters, feet or inches,
		 respectively.	The letter specification may be followed by a slash ('/') and an optional divisor.  For example, -dm/1000 would be
		 millimeters.	The  default  output  is in meters, regardless of the original units in the IES input file.  Note that there is no
		 space in this option.

       -i rad	 Ignore the crude geometry given by the IES input file and use instead an illum sphere with radius rad.  This option may be useful
		 when  the user wishes to add a more accurate geometric description to the light source model, though this need is obviated by the
		 recent LM-63-1995 specification, which uses MGF detail geometry.  (See -g option below.)

       -g	 If the IES file contains MGF detail geometry, compile this geometry into a separate octree and create a single instance referenc-
		 ing  it instead of including the converted geometry directly in the Radiance output file.  This can result in a considerable mem-
		 ory savings for luminaires which are later duplicated many times in a scene, though the appearance may suffer for  certain  lumi-
		 naires since the enclosed glow sources will not light the local geometry as they would otherwise.

       -f lampdat
		 Use lampdat instead of the default lamp lookup table (lamp.tab) to map lamp names to xy chromaticity and lumen depreciation data.
		 It is often helpful to have customized lookup tables for specific manufacturers and applications.

       -t lamp	 Use the given lamp type for all input files.  Normally, ies2rad looks at the header lines of the IES file to  try  and  determine
		 what  lamp is being used in the fixture.  If any of the lines is matched by a pattern in the lamp lookup table (see the -f option
		 above), that color and depreciation factor will be used instead of the default (see the -c and -u options).  The lamp	specifica-
		 tion is also looked up in the lamp table unless it is set to "default", in which case the default color is used instead.

       -c red grn blu
		 Use  the  given color if the type of the lamp is unknown or the -t option is set to "default".  If unspecified, the default color
		 will be white.

       -u lamp	 Set the default lamp color according to the entry for lamp in the lookup table (see the -f option).  This is the color that  will
		 be used if the input specification does not match any lamp type patterns.  This option is used instead of the -c option.

       -m factor Multiply  all output quantities by factor.  This is the best way to scale fixture brightness for different lamps, but care should
		 be taken when this option is applied to multiple files.

EXAMPLE

       To convert a single IES data file in inches with color balanced output and 15% lumen depreciation, creating  the  files	"fluor01.rad"  and
       "fluor01.dat" in the current directory:

	 ies2rad -di -t default -m .85 fluor01.ies

       To  convert  three  IES	files  of  various  types  to  tenths  of  a  foot  and put them in the library "/usr/share/radiance" subdirectory
       "source/ies":

	 ies2rad -df/10 -l /usr/share/radiance -p source/ies ies01 ies02 ies03

       To convert a single file and give the output a different name:

	 ies2rad -o fluorescent ies03

ENVIRONMENT

       RAYPATH	      directories to search for lamp lookup table

AUTHOR

       Greg Ward

BUGS

       In pre-1991 standard IES files, all header lines will be examined for a lamp table string match.  In post-1991 standard files,  only  those
       lamps  with  the  [LAMP] or [LAMPCAT] keywords will be searched.  The first match found in the file is always the one used.  This method of
       assigning colors to fixtures is less than perfect, and the IES would do well to include explicit  spectral  information	somehow  in  their
       specification.

       The  IESNA  LM-63 specification prior to 1995 provided three basic source shapes, rectangular, round, and elliptical.  The details of these
       shapes is vague at best.  Rectangular sources will always be rectangular, but ies2rad will approximate round sources as	spherical  if  the
       height  is  close  to  or  greater  than  the  width and length, and as a ring otherwise.  Elliptical sources are treated the same as round
       sources.  The 1995 standard rectifies this problem by including detailed luminaire geometry as MGF data, though	nothing  in  the  standard
       requires manufacturers to provide this information.

SEE ALSO

       mgf2rad(1), oconv(1), pfilt(1), rad2mgf(1), rpict(1), xform(1)

RADIANCE
							      6/14/96								IES2RAD(1)