Check out the thread entitled "Graphing on the Mac?" last November in
this news group (http://www.bio.net/hypermail/BIO-SOFTWARE/9611/).
There's lots of good advice there, not specifically about 3-D, but more
generally about Kaleidoscope, Igor and competing programs.
Incidentally, I agree with the general view expressed in November that
DeltaGraph is to be avoided like the plague. I struggle on with it (vn.
3.5) because I've invested a lot of time learning how to get it to do
what I want, but it's an awful program. It crashes a lot. It has
difficulty remembering settings from one session to the next (sometimes
even if you do something so simple as re-opening a file saved in a
previous session). It insists on displaying lots of graph options that I
never use and never would use (and offers no mechanism for suppressing
them: I haven't even managed with ResEdit). Its system for defining
functions doesn't work as the manual describes. It doesn't like non-USA
settings in the OS (probably this would be as much a nuisance for you in
Spain as it is in France). On my present Mac (7100/66 running FU1-7.5.3)
it pauses for several seconds before almost *any* operation (e.g. if you
click on an object absolutely *nothing* will happen for several
seconds): the only way I can get it to work at a reasonable speed is to
run it with *all* extensions (including those needed for printed) off,
which means, of course, that I can't prepare and print a graph without
rebooting in between.