[vtkusers] vtkMaskPolyData

[David Doria]

On Wed, Nov 4, 2009 at 3:07 PM, Yuri Alenka <yuralenka at googlemail.com> wrote:
> Hi,
>
> I have a surface from which I extract a subsample of points. I'm using
> vtkMaskPoints for that. Then I do some calculations with the pointset in ITK
> and get scalar values for each subsampled point. But I don't know how to set
> the values to the original surface because I don't have any indices with the
> corresponding original and downsampled points. Is there any way to get
> these? If there is an ITK class that can do that it would be also ok but I
> have worked more with VTK.
> The other problem I am thinking about is: Do I have to specify all scalars
> on the surface or are the colors interpolated at points I didn't specify?
>
> thanks

Yuri,

If all you are trying to do is downsample points, you can look at
vtkCleanPolydata (http://www.vtk.org/Wiki/Downsample_a_point_cloud)

Does anyone know the difference between vtkCleanPolyData and vtkMaskPoints?

It sounds like vtkMaskPoints doesn't pass anything through except the
geometry. If you use vtkCleanPolyData, you can add a PointID array to
the points and then you should be able to access the remaining parts
of this array after the downsampling. Let me know if you get anywhere
with that.

Thanks,

David