There are several methods of running the irradiance map viewer, which are outlined below.
The simplest way is to double-click the the imapviewer.exe file file. This will bring up an Open File dialogue box that lets you browse for an irradiance a light map to open. This is the same as starting the irradiance map viewer from the Start Menu. The menus of the program allow you to do various things with the irradiance light map (merging and saving etc).
You can also run the irradiance map viewer from the command line. In this case there are several possible choices:
If you type just
on the command line, this is the same as double-clicking the file. It will bring up the File Open dialogue for selecting an irradiance map or a light cache map file.
You can also type
> imapviewer <filename>
where <filename> is the name of an irradiance map or a light cache map file. This file will be opened automatically.
A third way is to use the viewer to merge several maps into one:
> imapviewer -load <map1> -load <map2> ... [-save<finalmap>] [-nodisplay]
This will load the specified maps and combine them into one irradiance light map of the same type. If the -save option is specified, the result will be written to the given file. If the -nodisplay option is specified, the resulting map will not be displayed (otherwise the viewer will display the final result).