[vtkusers] Strange behavior of vtkImageAlgorithm subclass - empty output

[David Doria]

On Fri, Jan 29, 2010 at 11:38 PM, Bill Lorensen <bill.lorensen at gmail.com> wrote:
> What results from:
> output->Print(std::cout);

1)
Is there a difference between
cout << *output;
and
output->Print(std::cout);
?

2)
I compared the output of 'grid' and 'output' (both inside
RequestData). Here are the differences:

grid:
  UpdateExtent: 0, 10, 0, 10, 0, 10
  WholeExtent: 0, 10, 0, 10, 0, 10

output:
  UpdateExtent: 0, -1, 0, -1, 0, -1
  WholeExtent: 0, -1, 0, -1, 0, -1

  MaximumNumberOfPieces: -1

Number of Points and Number Of Cells are correct in both. Everything
else is the same.

Thanks,

David