[vtkusers] remove triangles from polydata

[Dean Inglis]

thanks Dominik, that was what I needed.

Dean


Most likely you need the dataset surface filter.

Dominik

Dean Inglis wrote:
> Hi,
> 
>  
> 
> I have a vtkPolydata 3D surface comprised of triangles
> 
> with scalar values associated with the point data.  I want
> 
> to remove all triangles having a scalar value of 0 at all
> 
> three points of the triangles.  After which, I want to measure
> 
> the volume of the surface using vtkMassProperties. 
> 
> vtkThreshold does almost exactly
> 
> what I need with the exception that it outputs a
> 
> vtkUnstructuredGrid and not a vtkPolyData.  
> 
>  
> 
> vtkThreshold* threshold = vtkThreshold::New();
> 
> threshold->SetInputConnection( poly );
> 
> threshold->AllScalarsOn();
> 
> threshold->SetPointsDataTypeToFloat();
> 
> threshold->SetAttributeModeToUsePointData();
> 
> threshold->ThresholdByUpper( 0 );
> 
>  
> 
> How can I recover a vtkPolyData? I have
> 
> seen vtkUnstructuredGridToPolyDataFilter
> 
> but this is an abstract class.
> 
>  
> 
> Dean
> 
>  
> 
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> Dean Inglis, PhD
> 
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> ~~~~ Center for Appendicular ~~~~~
> 
> Magnetic Resonance Imaging Studies
> 
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> 610 - 25 Charlton Ave. E.
> 
> Hamilton, Ontario, L8N 1Y2
> 
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> Assistant Professor (Adjunct)
> 
> Department of Civil Engineering
> 
> McMaster University
> 
> Hamilton, Ontario
> 
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> Software Demos:
> 
> http://www.youtube.com/watch?v=_zYNtHC9-0s
> 
>  
> 
> 
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-- 
Dominik Szczerba, PhD
Computational Physics Group
IT'IS Foundation
http://www.itis.ethz.ch