[vtkusers] how can one use vtkBandedPolyDataContourFilter?

[Petru Pau]

I have a problem with vtkBandedPolyDataContourFilter. I'm trying to
make some bands on a sphere, and I always get an error message
"No input data".

Here is the code snippet that should do the work:

           vtkBandedPolyDataContourFilter bcf = 
vtkBandedPolyDataContourFilter.New();
           bcf.SetInput(sphere);
           bcf.SetNumberOfContours(10);
           for (int i=0; i<9; i++)
               bcf.SetValue(i,i);
           bcf.SetScalarModeToIndex();
           bcf.GenerateContourEdgesOn();

           float[] vals = bcf.GetValues();

The variable "sphere" stores a vtkPolyData - a sphere centered in 0 of 
radius 1.

The array of floats "vals", at the end, has length 0 - the values 
returned by
GetValues. Why?

Petru