[vtkusers] A question regarding vtkGeometryFilter...

[Steve Boyd]

Hi,

I am trying to extract the surface of my vtkUnstructuredGrid data with
vtkGeometryFilter, but when I look at the number of points in the
extracted surface (from vtkGeometryFilter) it is still equal to the
number of points in the original structure.  

Does vtkGeometryFilter extract vtkPolyData cells and just pass the point
data through?  If so, how can I update my output so that only points
used by the vtkPolyData cells representing the surface of my data are
passed through?  I want to smooth only the surface points of my
vtkUnstructuredGrid data with vtkSmoothPolyDataFilter.

A couple of lines of my code look something like this:

vtkUnstructuredGridSource *voi;  // updated and filled with data.
vtkExtractGeometry *geo = vtkExtractGeometry::New();
  geo->SetInput(voi->GetOutput());
  geo->Update();
if (voi->GetOutput()->GetNumberOfPoints() ==
geo->GetOutput()->GetNumberOfPoints())
  cout << "What the heck?" << endl;

Thanks for any help!

Cheers,

Steve

-- 
Steven Boyd, PhD

Institute for Biomedical Engineering
ETH and University Zuerich
Moussonstrasse 18
8044 Zuerich, Switzerland

tel. +41.1.632.4591  fax. +41.1.632.1214  boyd at biomed.ee.ethz.ch
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