[vtkusers] Pick function

[s1337m at comcast.net]

I want to extract the mesh coordinate from a mesh I have using the vtkRenderWindowInteractor because vtkAbstractPicker is built into the interactor with the p button.  I read the User Guide and the docs, and I'm pretty sure I need to use the vtkCellPicker.  I need some help using it though; how do I set up a loop where the window continues to render and I can get multiple picks per program instance? 

Sean Mann