VisAD Newbie : Help with doing simple 3D plot

I've been playing around with VisAD a bit, but I seriously think that I'm
not getting anywhere by myself. I really need help. So if any of these sound
too easy for you, please be patient. Thanks.

I'm basically just trying to do a 3D plot, but don't really understand how
VisAD works, particularly the data model. I've read the VisAD guide, but to
no avail. Too much information which I don't understand, probably. I've also
gone through some of the progams in the examples directory, but i can't find
any documentation describing what each test program is trying to do, so not
too much help there either.