[vtkusers] I just get an isosurface with vtkSurfaceReconstructionFilter and vtkContourFilter?

[David Jakobsson]

Hi all,

I have an unorganized point cloud of a surface, x, y and z-coordinates, with a scalar value for each point. I make a vtkPolyData object of the points and scalars, and then I use vtkSurfaceReconstructionFilter and vtkContrastFilter to generate a surface and display it. It works fine except I just get an isosurface. I wish to see the scalars on the surface. How do I achieve that and what am I doing wrong???

Any help is greatly appreciated! I started to learn VTK last week.

Thank you for your time,
David



Below is parts of my code (Java):

...

    // Points
    vtkPoints p = new vtkPoints();
    // Vertices
    vtkCellArray verts = new vtkCellArray();
    // Scalars
    vtkDoubleArray intensities = new vtkDoubleArray();
    int index = 0;
    for (int i = 0; i < borders.sliceCount(); i++) {
      for (int j = 0; j < borders.rowCount(); j++) {
        for (int k = 0; k < borders.columnCount(); k++) {
          if (borders.getBoolean(i, j, k)) {
            p.InsertPoint(index, i, j, k);
            verts.InsertNextCell(1);
            verts.InsertCellPoint(index);
            intensities.InsertTuple1(index, intensities);
            index++;
          }
        }
      }
    }

    // Insert points, vertices and scalars
    pointCloud = new vtkPolyData();
    pointCloud.SetPoints(p);
    pointCloud.SetVerts(verts);
    pointCloud.GetPointData().SetScalars(intensities);
    
    
    // Contruct a surface reconstruction filter
    vtkSurfaceReconstructionFilter surfaceFilter = new vtkSurfaceReconstructionFilter();
    surfaceFilter.SetInput(pointCloud);
    vtkImageData id = surfaceFilter.GetOutput();

    // Contour filter
    vtkContourFilter cf = new vtkContourFilter();
    cf.SetInput(id);
    cf.SetValue(0,0);
    brainSurface = cf.GetOutput();

...

    vtkPolyDataMapper pointMapper = new vtkPolyDataMapper();
    pointMapper.SetInput(bss.getPointCloud());
    pointMapper.ScalarVisibilityOff();

    vtkPolyDataMapper surfaceMapper = new vtkPolyDataMapper();
    surfaceMapper.SetInput(bss.getBrainSurface());
    surfaceMapper.SetScalarRange(0,1000);
    surfaceMapper.ScalarVisibilityOn();

    vtkActor pointActor = new vtkActor();
    pointActor.SetMapper(pointMapper);

    vtkActor surfaceActor = new vtkActor();
    surfaceActor.SetMapper(surfaceMapper);
    // Remove light
    surfaceActor.GetProperty().SetAmbient(1);
    surfaceActor.GetProperty().SetDiffuse(0);
    surfaceActor.GetProperty().SetSpecular(0);
    
    vtkRenderer ren1 = new vtkRenderer();
    ren1.AddActor(pointActor);
    ren1.SetBackground(0.1, 0.2, 0.4);
    ren1.SetViewport(0.0, 0.0, 0.5, 1.0);

    vtkRenderer ren2 = new vtkRenderer();
    ren2.AddActor(surfaceActor);
    ren2.SetBackground(0.1, 0.2, 0.4);
    ren2.SetViewport(0.5, 0.0, 1.0, 1.0);

    vtkRenderWindow renWin = new vtkRenderWindow();
    renWin.AddRenderer(ren1);
    renWin.AddRenderer(ren2);
    renWin.SetSize(600, 300);