[vtkusers] Labeling points of an unstructured grid

[John Platt]

Hi,

vtkUnstructuredGridGeometryFilter creates new,  0-based, contiguous, points 
and cell ids. I suspect you are labelling these new ids. Have you tried 
putting the id filter before the geometry filter?

HTH

John.

----- Original Message ----- 
From: "Jochen" <jochen.kling at email.de>
To: <vtkusers at vtk.org>
Sent: Tuesday, February 28, 2012 12:24 AM
Subject: [vtkusers] Labeling points of an unstructured grid


> Hi all,
>
> I would like to label all points of an unstructured grid with their 
> original
> id. This sounds like easy to accomplish. I'm running out of any idea what
> I'm doing wrong. And to be honest, I'm out of order now. Hopefully there 
> is
> somebody out there, who can help me.
>
> (my context: vtk 5.8.0, activiz, c#)
>
> As soon as I add /vtkUnstructuredGridGeometryFilter/-filter points are
> labeled with wrong ids.
> In the case I use the pure grid as input for /vtkIdFilter/ everything is
> fine except that I see labels for inner points, which I cannot accept.
>
> This code shows the correct ids: ( but I see the inner points)
>
> private void ShowNodes() {
> vtkUnstructuredGridReader reader;
> vtkUnstructuredGrid ugrid;
> vtkVertexGlyphFilter vertexFilter;
> vtkIdFilter idFilter;
> vtkPolyDataMapper ptsMapper;
> vtkLabeledDataMapper lblMapper;
> vtkActor ptsActor;
> vtkActor2D lblActor;
>
> // read ugrid
> reader = vtkUnstructuredGridReader.New();
> reader.SetFileName(@"c:\vtk\data\cube.1.vtk"); // created by tetgen.exe
> (cube with 48 tetrahedrons)
> reader.Update();
> ugrid = reader.GetOutput();
>
> // filter original point ids
> idFilter = vtkIdFilter.New();
> idFilter.SetInputConnection(ugrid.GetProducerPort());
> idFilter.PointIdsOn();
> idFilter.Update();
>
> // points
> vertexFilter = vtkVertexGlyphFilter.New();
> vertexFilter.SetInputConnection(ugrid.GetProducerPort());
> vertexFilter.Update();
> ptsMapper = vtkPolyDataMapper.New();
> ptsMapper.SetInputConnection(vertexFilter.GetOutputPort());
> ptsMapper.ScalarVisibilityOn();
> ptsActor = vtkActor.New();
> ptsActor.SetMapper(ptsMapper);
> ptsActor.GetProperty().SetPointSize(10.0f);
>
> // point labels
> lblMapper = vtkLabeledDataMapper.New();
> lblMapper.SetInputConnection(idFilter.GetOutputPort());
> lblMapper.SetLabelModeToLabelFieldData();
> lblActor = vtkActor2D.New();
> lblActor.SetMapper(lblMapper);
>
> // render
> renderer.AddActor(ptsActor);
> renderer.AddActor(lblActor);
> renWin.Render();
> }
>
> ----------------------------------------------------
> This code shows totally wrong ids (Differences to code above in bold)
>
> private void ShowSurfaceNodes() {
> vtkUnstructuredGridReader reader;
> vtkUnstructuredGrid ugrid;
> vtkVertexGlyphFilter vertexFilter;
> vtkIdFilter idFilter;
> vtkPolyDataMapper ptsMapper;
> vtkLabeledDataMapper lblMapper;
> vtkActor ptsActor;
> vtkActor2D lblActor;
> * vtkUnstructuredGridGeometryFilter geo;
> *
> // read ugrid
> reader = vtkUnstructuredGridReader.New();
> reader.SetFileName(@"c:\vtk\data\cube.1.vtk"); // created by tetgen.exe
> (cube with 48 tetrahedrons)
> reader.Update();
> ugrid = reader.GetOutput();
>
> // filter inner points, so only surface points will be available
> * geo = vtkUnstructuredGridGeometryFilter.New();
> geo.SetInputConnection(ugrid.GetProducerPort());
> *
> // filter original point ids
> idFilter = vtkIdFilter.New();
> idFilter.SetInputConnection(*geo.GetOutputPort()*);
> idFilter.PointIdsOn();
> idFilter.Update();
>
> // points
> vertexFilter = vtkVertexGlyphFilter.New();
> vertexFilter.SetInputConnection(*geo.GetOutputPort()*);
> vertexFilter.Update();
> ptsMapper = vtkPolyDataMapper.New();
> ptsMapper.SetInputConnection(vertexFilter.GetOutputPort());
> ptsMapper.ScalarVisibilityOn();
> ptsActor = vtkActor.New();
> ptsActor.SetMapper(ptsMapper);
> ptsActor.GetProperty().SetPointSize(10.0f);
>
> // point labels
> lblMapper = vtkLabeledDataMapper.New();
> lblMapper.SetInputConnection(idFilter.GetOutputPort());
> lblMapper.SetLabelModeToLabelFieldData();
> lblActor = vtkActor2D.New();
> lblActor.SetMapper(lblMapper);
>
>
> renderer.AddActor(ptsActor);
> renderer.AddActor(lblActor);
> renWin.Render();
> }
>
> I hope code is not too long.
> Please help. I tried so many things, unfortunately with no success.
>
> with kind regards
> Jochen
>
>
>
> --
> View this message in context: 
> http://vtk.1045678.n5.nabble.com/Labeling-points-of-an-unstructured-grid-tp5520458p5520458.html
> Sent from the VTK - Users mailing list archive at Nabble.com.
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