[vtkusers] Update vtkDelaunay2d object

[David Doria]

2010/2/22 Jordi Gutiérrez Hermoso <jordigh at gmail.com>

> I have code like this in a class:
>
>    //add the grid points to the polydata object
>    vtkSmartPointer<vtkPolyData> polydata = vtkPolyData::New();
>    polydata->SetPoints(points);
>    polydata->GetPointData() -> SetScalars(scalars);
>
>    //triangulate the grid points
>    vtkSmartPointer<vtkDelaunay2D> delaunay = vtkDelaunay2D::New();
>    delaunay->SetInput(polydata);
>    delaunay->Update();
>
> And later this goes through the pipeline until I generate a plot.
>
> I want to plot a moving surface, so that the polydata object needs to
> be updated but only the z-coordinates, so that the actual Delaunay
> triangulation shouldn't have to be computed again.
>
> How can I update the polydata object with new points and scalars
> without recomputing a Delaunay triangulation?
>
> Thanks,
> - Jordi G. H.
>
>
First, this:
   vtkSmartPointer<vtkPolyData> polydata = vtkPolyData::New();

is very bad. You must use
   vtkSmartPointer<vtkPolyData> polydata =
vtkSmartPointer<vtkPolyData>::New();

It shouldn't be a problem to do what you are asking, I think you can just
get the output of the Delaunay filter and update its points:

vtkPolyData* output = delaunay->GetOutput();
output->SetPoints(newPoints);
output->GetPointData()->SetScalars(newScalars);

Maybe I misunderstood your question?

Thanks,

David
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