GLASSEMBLY GLASSEMBLY Create a GL Assembly

Usage

Define a GL Assembly.  A GL Assembly consists of one or more
GL Nodes or GL Assemblies that are placed relative to the 
coordinate system of the assembly.  For example, if we have
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.
