[vtkusers] picking points

[Magnus Hagdorn]

hi there,
i am a new vtk user and am slowly getting to grips with vtk. i use the
python wrapper (which unfortunately does come with to much documentation,
getting there though). now what i'd like to do is the following:
- i've got a base topography on a structured grid with the z coordinate
  being height above sea level
- i've got point data (unstructed grid) which i visualise with spheres
- at each point i've got a time series (relative sea level change). i 
  would like to be able to click on a sphere and then pop up a new 
  window showing a scatter plot. can i use one of the pickers for that?
  if so, how.
a related problem is that i need to translate the vertical pos of the
spheres. so far i just set the z coord to 0 (which works most of the time
since the data tend to be along the coast). is there a simple way to
interpolate the topography (i.e. z-coord) at my locations?
cheers
magi

-------------
Magnus Hagdorn
Department of Geology and Geophysics
The University of Edinburgh
Grant Institute
West Mains Road
Edinburgh EH9 3JW
Scotland
PHONE: (+44) 131 650 5917
FAX:   (+44) 131 668 3184
email: Magnus.Hagdorn at glg.ed.ac.uk