[vtkusers] (no subject)

[vtk_project at bonusfive.com]

Hi.  We're trying to retrieve points on polygon data
based on the position of the mouse pointer, and then
trying to return the scalar value associated with that
point (all in tcl).  So far, we've tried using a
vtkStyleInteractorUser which is giving what seems to be
just the x and y position in the window, not relevant
to the data.  We thought that maybe using the GetZ?
function would yield coordinates we could use to
retrieve the scalar values, but we can't get GetZ
working.  Is this a situation where point picking is
used?  If so, how is that done?  And how do we isolate
scalar values based on point?  Thank you for any help
you can give.  (Background note: This is a student
project at UMBC on haptic display of surface certainty;
the scalar values will be used by a Phantom device to
give haptic feedback based on the user's pointing
position)

-Andy Grossman and Kirk
Petri