3-D visualization in GRASS

[Darrell McCauley]

g.gnuplot can do quite a few things (all the capabilities of gnuplot,
including contouring, multiple 3D surfaces, hidden line removal,
surface suspended above contours, etc). Find the latest beta release
of gnuplot (3.3b10?) - the grass program is in there.

I'll make a tutorial on extracting grass data for this
program available on pasture.ecn.purdue.edu as soon
as I get some other things finished (like s.semivar--yes,
I am still working on this).

--Darrell