[vtkusers] simple question vtkCleanPolyData

[Janet Kim]

As and addendum to this question - if you are using
vtkCleanPolyData and have SetScalars to set a vtkFloatArray
to that polydata, how can you correspondingly clean the
scalars as well?  When I had tried to clean the poly data,
I found that my scalars remained the same, and consequently
were all off.  Is there a way to do this?

janet

On Tue, 18 Apr 2006, Jean-Dominique Barnichon wrote:

> Thanks for the tip Amy,
> I should be able to get it now.
> Jean-Do
>
> Amy Squillacote a écrit :
>> Hi Jean-Do,
>> 
>> No, there is not a filter in VTK to only remove duplicate points in a 
>> dataset with no cells.  One thing you could do is to add a vtkVertex cell 
>> per point in your dataset.  Then if you pass this new dataset through 
>> vtkCleanPolyData, duplicate points will be merged, but you won't have the 
>> problem of points being removed because they are not being used by a cell.
>> 
>> - Amy
>> 
>> At 02:47 AM 4/18/2006, jeando.barnichon at free.fr wrote:
>>> Ok, I understand.
>>> The next question now is :
>>> Is there a filter that could do the "simple" task of "cleaning" (i.e. 
>>> removing
>>> duplicate points) a polydata that is made of points only?
>>> Jean-Do
>>> 
>>> Selon Amy Squillacote <amy.squillacote at kitware.com>:
>>> 
>>> > You are right; you do need cells in your vtkPolyData, not just
>>> > points.  This is because one of the features of vtkCleanPolyData is
>>> > to remove points that are not used by any cells.  Thus if your data
>>> > has no cells, then this is true for all the points in your data set,
>>> > so all of them will be removed, resulting in an empty vtkPolyData data 
>>> set.
>>> >
>>> > - Amy
>>> >
>>> > At 05:06 PM 4/17/2006, Janet Kim wrote:
>>> > >I tried out vtkCleanPolyData and it looked like you
>>> > >might need actual geometry for the polydata to clean,
>>> > >not just points.  When I just had points, I had the
>>> > >same result.  But once I added the points to cells,
>>> > >the clean worked.  Maybe someone else can explain a
>>> > >bit better, unless, I'm wrong.
>>> > >
>>> > >
>>> > >On Mon, 17 Apr 2006, Jean-Dominique Barnichon wrote:
>>> > >
>>> > >>Should be a simple one.
>>> > >>I've got a polydata containing only points (see end of email), some
>>> > >>of which are duplicate points.
>>> > >>I want to keep only a single point with given coordinates (yes, I
>>> > >>know that the vtkCleanPolyData filter should do the trick, but I
>>> > >>just can couldn't get it working so far).
>>> > >>When I run the piece of code given below, the cleaned polydata is
>>> > >>empty (i.e. it has 0 points), and I don't understand why.
>>> > >>Any Idea?
>>> > >>Jean-Do
>>> > >>
>>> > >>Code snippet:
>>> > >>       vtkPolyDataReader *re = vtkPolyDataReader::New();
>>> > >>       re->SetFileName("InitialPolydata.vtk");
>>> > >>
>>> > >>       vtkPolyData *pdata = vtkPolyData::New();
>>> > >>       pdata = re->GetOutput();
>>> > >>
>>> > >>       // pdata is the vtkPolyData
>>> > >>       vtkCleanPolyData *Clean = vtkCleanPolyData::New();
>>> > >>       Clean->SetInput(pdata);
>>> > >>       Clean->SetTolerance(0.0);
>>> > >>       Clean->PointMergingOn();
>>> > >>       Clean->Update();
>>> > >>
>>> > >>       vtkPolyDataWriter *wr = vtkPolyDataWriter::New();
>>> > >>       wr->SetFileName("CleanedPolydata.vtk");
>>> > >>       wr->SetInput(Clean->GetOutput());
>>> > >>       wr->Write();
>>> > >>
>>> > >>
>>> > >>//beginning_of_file (InitialPolydata.vtk)
>>> > >># vtk DataFile Version 3.0
>>> > >>vtk output
>>> > >>ASCII
>>> > >>DATASET POLYDATA
>>> > >>POINTS 12 float
>>> > >>3.35936 1.84257 49.9219 6.3551 1.84257 40.9347 17.8945 1.84257 39.9079
>>> > >>17.8945 1.84257 39.9079 25.3551 1.84257 23.6583 25.3551 1.84257 
>>> 23.6583
>>> > >>34.0223 1.84257 20.6629 34.0223 1.84257 20.6629 36.8945 1.84257 
>>> 20.1843
>>> > >>45.263 1.84257 1.84257 45.263 1.84257 1.84257 83.3594 1.84257 0
>>> > >>
>>> > >>POINT_DATA 12
>>> > >>//end_of_file
>>> > >>
>>> > >>_______________________________________________
>>> > >>This is the private VTK discussion list. Please keep messages
>>> > >>on-topic. Check the FAQ at: http://www.vtk.org/Wiki/VTK_FAQ
>>> > >>Follow this link to subscribe/unsubscribe:
>>> > >>http://www.vtk.org/mailman/listinfo/vtkusers
>>> > >_______________________________________________
>>> > >This is the private VTK discussion list. Please keep messages
>>> > >on-topic. Check the FAQ at: http://www.vtk.org/Wiki/VTK_FAQ
>>> > >Follow this link to subscribe/unsubscribe:
>>> > >http://www.vtk.org/mailman/listinfo/vtkusers
>>> >
>>> >
>>> >
>> 
>> 
>> 
>> 
>
> _______________________________________________
> This is the private VTK discussion list. Please keep messages on-topic. Check 
> the FAQ at: http://www.vtk.org/Wiki/VTK_FAQ
> Follow this link to subscribe/unsubscribe:
> http://www.vtk.org/mailman/listinfo/vtkusers
>