[vtkusers] Testing a point in a domain, and interpolating data

[Shawn Ericson]

I am a newbie to vtk with moderate experience creating and manipulating 
actors. I am now looking at using vtk to assist some simple computational 
post-processing, dealing directly with data. I have two vtk books, but I am 
not yet familiar enough with the API to know how to get started. My domain is 
a single object created from an unstructure grid with scalar values at every 
node.

1. If I select an arbitrary point in space (x1,y1,z1) is there a way that I 
can test whether or not this point in inside or outside my domain?
2. If this point is in the domain, I want to extract a scalar value, but the 
point may not be directly on a node, so the value must be interpolated from 
surrounding nodes. Does the vtk API have a means to do this?

Examples would be helpful, but keywords that can start me on my way are 
sufficient. Thanks in advance.

Shawn


------------------------------------------------------------------------
Shawn Ericson
University of Tennessee - Joint Institute for Computational Science
& the Computational Fluid Dynamics Laboratory
@ the Oak Ridge National Laboratory, Oak Ridge, Tennessee
sericson at jics.utk.edu