"drawing" grid lines on a surface

I'm trying to figure out the most sensible way to do something. I have a
surface in 3D space,
which may be either an Irregular2DSet or a Linear2DSet (onto which the
Irregular2DSet has been
sampled). A "data" variable determines height of the surface.

I'd like to "draw" grid lines that follow the surface at particular x or y
values; this would enable someone
looking at it to better figure out which parts of the surface relate to
which x and y values.  Other than
drawing a bunch of independent "lines" and adding them to the Display
(which seems a bit
unwieldy), I haven't come up with any brilliant ideas. Is there a sensible
way to do this? Is there
a simple way to create a grid of *lines*, give them a height (or z) value
by sampling the data set onto them, and
then display that?

Donna L. Gresh, Ph.D.
Optimization and Mathematical Software Group
IBM T.J. Watson Research Center
(914) 945-2472