Section: OpenGL Models
glnode definitions for 'bread' and 'cheese', then
a glassembly of sandwich would consist of placements of
two 'bread' nodes with a 'cheese' node in between.
Furthermore, a 'lunch' assembly could consist of a 'sandwich'
a 'chips' and 'soda'.  Hopefully, you get the idea.  The
syntax for the glassembly command is
glassembly(name,part1,transform1,part2,transform2,...)
where part1 is the name of the first part, and could be
either a glnode or itself be another glassembly.  
Here transform1 is the 4 x 4 matrix that transforms
the part into the local reference coordinate system.
WARNING!! Currently FreeMat does not detect or gracefully handle 
self-referential assemblies (i.e, if you try to make a sandwich 
contain a sandwich, which you can do by devious methods that I 
refuse to explain).  Do not do this!  You have been warned.