Q: I want TriD, but include files are not found.
A: You need to add -I/usr/openwin/include etc. (or whatever is appropriate
on your platform) to the relevant entry in perldl.conf (see above),
i.e. something like
      OPENGL_INC => '-I/usr/openwin/include',
Additionally, you might have to specify name and location of the appropriate
library on your platform, e.g.
      OPENGL_LIBS =>
   '-L/usr/openwin/lib -L/usr/X11R6/lib -L/usr/lib/mesa -lGL'.
 ' -lGLU -lXext -lX11',
You may also need to pass some flags to cpp, see the README in the
PDL/Graphics/TriD/OpenGL directory for details.
      OPENGL_DEFINE => '-DGL_GLEXT_LEGACY',
Then, start the build process again as described above
(from the toplevel):
   perl Makefile.PL
etc...
Q: Compilation of TriD complains about undefined functions or somesuch.
A: Please see the file Graphics/TriD/OpenGL/README.  If that doesn't help
   please report this problem to pdl-porters@jach.hawaii.edu, include the
   appropriate platform and GL version information.