[vtkusers] vtkPoints from a triangular vtkPolyData

[Tim Hutton]

Hi imho,

If your polydata is the output of a filter (like vtkTriangleFilter) then 
you will need to call Update on it in order to use its output, else 
GetNumberOfPoints will return zero and GetPoint won't work.

If you've made your own polydata then there must be something wrong with 
how the points were assigned. Perhaps if you send us your code for that bit 
we might be able to help.

Also worth checking that the in and out points are different...

Tim

At 14:32 14/08/2003 +0200, imho wrote:
>Hi all,
>I'd like to use the vtkThinPlateSplineTransform, who needs vtkPoints 
>structures.
>I've tried poly->getPoints()  but it was empty, so here's what I've done:
>models are vtkPolyData
>TPSTarget and Origine  vtkPoints
>
>        n1 = modelTarget->GetNumberOfPoints();
>        n2 = modelToMove->GetNumberOfPoints();
>        if (n1 < n2)
>            n=n1;
>        else
>            n=n2;
>
>        for (i=0; i<n; i++)
>        {
>            modelTarget->GetPoint(i,point);
>            TPSTarget->InsertNextPoint(point);
>        }
>
>
>        for (i=0; i<n; i++)
>        {
>            modelToMove->GetPoint(i,point);
>            TPSOrigine->InsertNextPoint(point);
>        }
>
>
>        TPSTr->SetSourceLandmarks(TPSOrigine);
>        TPSTr->SetTargetLandmarks(TPSTarget);
>
>and then :
>    tf3 = vtkTransformPolyDataFilter::New();
>
>    tf3->SetTransform(TPSTr);
>    tf3->SetInput(poly);
>    tf3->Update();
>
>    return (tf3->GetOutput());
>
>but it does nothing, my poly is the same on input and output., for the 
>same reason before I guess.
>What can I try to have points from my polyData?
>
>Thanks
>
>
>
>_______________________________________________
>This is the private VTK discussion list. Please keep messages on-topic. 
>Check the FAQ at: <http://public.kitware.com/cgi-bin/vtkfaq>
>Follow this link to subscribe/unsubscribe:
>http://www.vtk.org/mailman/listinfo/vtkusers
>