[vtkusers] Bug in: vtkWindowedSincPolyDataFilter

[Jonathan Waite]

Hello,

 

I believe I found a bug in vtkWindowedSincPolyDataFilter. The filter appears
to slightly translate the data on larger datasets ~= 50,000.  I ran it with
the following code on several data sets,

 

      vtkWindowedSincPolyDataFilter * smoother =
vtkWindowedSincPolyDataFilter::New();

      smoother->SetInput(map->GetInput());  //map is a vtkPolyDataMapper

      smoother->SetNumberOfIterations(20);

      smoother->SetPassBand(0.1);

      smoother->Update();

 

The shift appears to always be within -1 >=  <=1, which makes me think some
kind of rounding error is happening.  While going from dataset to dataset,
the shift varies; on the same dataset, the shift appears to remain constaint
allowing you to see the movement.  It is difficult to see the error unless
the filter is run 5-7 times, but afterwards if you compare to the original
dataset, the shift should be obvious.

 

I have uploaded some example files (see below)

The example will show the model shifting and then do a 360 turn to show the
result.  The initial model (white) is 0.5 opaque to better demonstrate the
shift.

 

The files can also be found here:

http://68.32.98.82/cone.cxx

http://68.32.98.82/testP.vtk

 

Thanks in advance,

Jon

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