This type of optimization is most useful for windows and skylights which represent concentrated sources of indirect illumination. Mkillum is not appropriate for very large sources or sources with highly directional distributions. 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.
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. 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.