[vtkusers] vtkContourFilter issue

[David Doria]

On Wed, Dec 9, 2009 at 10:04 AM, Bill Lorensen <bill.lorensen at gmail.com> wrote:
> You need to set the value to be extracted by the contour filter. You
> also need to Update() the contour filter before requesting its output.
>
> Or, did you just leave out those in your e-mail?

Francois,
Good point, that would have been a bug in my algorithm, but it
shouldn't prevent SOMETHING from happening (i.e. not producing a
PolyData with 0 points and cells).

Bill,
Yes, sorry I omitted that part:

    vtkSmartPointer<vtkContourFilter> contourFilter =
        vtkSmartPointer<vtkContourFilter>::New();
    contourFilter->SetValue(0, 0); // the 0th contour should be the 0 contour
    contourFilter->SetInput(grid);
    contourFilter->Update();
    vtkPolyData* surface = contourFilter->GetOutput();
    vtkstd::cout << "Number of points: " <<
surface->GetNumberOfPoints() << vtkstd::endl;
    vtkstd::cout << "Number of cells: " << surface->GetNumberOfCells()
<< vtkstd::endl;

Number of points: 0
Number of cells: 0

I checked that the values of 'd' that are being set in:
grid->SetScalarComponentFromDouble(x,y,z,0,d);
are valid and they are.

Any other thoughts?

Thanks,

David