[vtkusers] Problems calling GetPixelValue

[Julian Humphries]

Environment:

Recent vtkNightly
Python 1.5
Win2k

Trying to get scalar value for a pixel with call to 
vtkRenderWindow.GetPixelData():

winRen.GetPixelValue(x,y,x,y,1)

I am getting a NameAttribute error for GetPixelData.  This would seem to be 
a valid property for a vtkRenderWindow, any help on what I am doing 
wrong?  I can get other properties of the render window with no difficulty.

Julian Humphries
University of Texas