The arguments to mkillum are passed directly to rtrace(1), which is used to compute the light distributions for the input surfaces. These surfaces can be any combination of polygons, spheres and rings. Other surfaces may be included, but mkillum cannot compute their distributions.
By default, mkillum reads from its standard input and writes to its standard output. It is possible to specify multiple input files in a somewhat unconventional fashion by placing a lesser-than symbol ('<') before the file names. (Note that this character must be escaped from most shells.) This is necessary so mkillum can tell where the arguments to rtrace(1) end and its own input files begin.
#@mkillum variable=value option switch{+|-} ..
String or integer variables are separated from their values by the equals sign ('='). Options appear by themselves. Switches are followed either by a plus sign to turn them on or a minus sign to turn them off.
Parameters are usually changed many times within the same input file to tailor the calculation, specify different labels and so on. The parameters and their meanings are described below.
o=string Set the output file to string. All subsequent scene data will be sent to this file. If this appears in the first comment in the input, nothing will be sent to the standard output. Note that this is not recommended when running mkillum from rad(1), which expects the output to be on the standard output.
m=string Set the material identifier to string. This name will be used not only as the new surface modifier, but it will also be used to name the distribution pattern and the data files. The distribution name will be string plus the suffix ".dist". The data file will be named string plus possibly an integer plus a ".dat" suffix. The integer is used to avoid accidently writing over an existing file. If overwriting the file is desired, use the f variable below.
f=string Set the data file name to string. The next data file will be given this name plus a ".dat" suffix. Subsequent files will be named string plus an integer plus the ".dat" suffix. An existing file with the same name will be clobbered. This variable may be unset by leaving off the value. (See also the m variable above.)
i=string Only produce secondary sources for surfaces modified by string.
d=integer Set the number of direction samples per projected steradian to integer. The number of directions stored in the associated data file will be approximately this number multiplied by pi for polygons and rings, and by 4pi for spheres. If integer is zero, then a diffuse source is assumed and no distribution is created.
s=integer Set the number of ray samples per direction to integer. This variable affects the accuracy of the distribution value for each direction as well as the computation time for mkillum.