[vtkusers] Getting Point Data from vtkPolyData object

[T.R.Shashwath]

On Friday 24 Jul 2009 11:16:36 pm Venkattraman A wrote:
> Hi,
>
> I have a vtkPolyDataReader that reads in a very small input file with two
> scalars and 6 data points. I use that to create an XYPlot and it all works
> like a treat. I wanted to print the point data to the terminal (for no
> specific reason) and tried to use the vtkPolyData object that is output
> from the vtkPolyDataReader object. When I printed the output from the
> reader object, it seems to say give 0 for Number of Points, Number of Cells
> etc etc etc. My XYPlot ouput is as expected. Is there something I am
> missing? This has been reported before but I couldn't find a solution.
>
> Thanks,
> Venkat

Hi Venkat,
Try adding an Update() call to the reader before getting its output.

The filter stages - including readers and writers don't do anything unless 
they're updated. When they're put into a renderer's pipeline, Update is called 
by the renderer itself. But when you use them outside, you've got to manually 
do it before using the output objects.

Regards,
Shash