pickdata and select again....

["Richard Tyc" <richt(at)sbrc.umanitoba.ca>]

OK, I am at this problem again with a little more understanding and more
time to look for solutions.
I think I understand the use of select (isolate which objects you have
selected) and pickdata (get xyz data of object based on screen location and
zbuffer data).  I did look at Randall Frank's solution of using mask objects
at key locations (eq. end of a line) to force selection and not rely on xyz
data from pickdata.

But I want to do more...
Q. Is there a way to select anywhere on a texture mapped IDLgrPolygon object
to retrieve a 3D location of the current mouse position ?  pickdata seems to
choke on this providing unrealistic xyz data.  Am I asking for too much ?

Rich