[vtkusers] Contouring Vertices

[Erik Sobel]

What's the best way to apply a contour to a unstructured grid of polydata 
vertices - I basicaly want to throw a rubber sheet over a collection of 
points.  I'm not having much luck with...
vtkContourFilter
vtkKitwareContourFilter
vtkMarchingContourFilter

- but it's hard to tell if I am using them correctly since I get no output.

Anyone have any suggestions?

Thanks,
Erik