[vtkusers] Exposed surface area

[Kent Vander Velden]

  This is perhaps a bit of a long shot, but if someone on this list
has done this before or has a suggestion it will be greatly worth asking.

  I have a number of spheres that form a bumpy surface.  I then have another
ball, a probe, that I would like to "rub" over the top of the bumpy surface.  While
rubbing this probe over the surface I would like to associate with each sphere
composing the bumpy surface the percentage of the sphere's surface that the probe
can touch.  Please note that some parts of the spheres may be accessible if the 
probe is less than a certain diameter but not accessible as the diameter increases.

  Chemistry people use these to compute surface accessibility of molecules.  There
is related item called the Connolly surface.  While these techniques may work I have
yet to find a suitable tool that I can use (mainly time issues or legal issues get
in the way - NDAs typically needed).  

  Does VTK have components that could be used to compute surface accessibility?
What pieces of VTK would you recommend looking at?  Hopefully I just need a
few pointers to get headed in the right direction or someone to warn against
going this path.

  Thanks.

---
Kent Vander Velden
kent at iastate.edu