CellCenters

VTKExamples/Java/PolyData/CellCenters


Description

vtkCellCenters is a filter that takes as input any dataset and generates on output points at the center of the cells in the dataset.

These points can be used for placing glyphs vtkGlyph3D) or labeling.

Other Languages

See (Cxx)

Question

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Code

CellCenters.java

import vtk.vtkActor;
import vtk.vtkNativeLibrary;
import vtk.vtkRenderWindow;
import vtk.vtkRenderWindowInteractor;
import vtk.vtkRenderer;
import vtk.vtkImageData;
import vtk.vtkCellCenters;
import vtk.vtkDataSetMapper;


public class CellCenters 
{
  // -----------------------------------------------------------------
  // Load VTK library and print which library was not properly loaded
  static 
  {
    if (!vtkNativeLibrary.LoadAllNativeLibraries()) 
    {
      for (vtkNativeLibrary lib : vtkNativeLibrary.values()) 
      {
        if (!lib.IsLoaded()) 
        {
          System.out.println(lib.GetLibraryName() + " not loaded");
        }
      }
    }
    vtkNativeLibrary.DisableOutputWindow(null);
  }
  // -----------------------------------------------------------------

  public static void main(String args[]) 
  {  
    // Create an image data
    vtkImageData imageData = new vtkImageData();

    // Specify the size of the image data
    imageData.SetDimensions(3,3,2);
    imageData.SetSpacing(1.0, 1.0, 1.0);
    imageData.SetOrigin(0.0, 0.0, 0.0);

    vtkCellCenters cellCentersFilter = new vtkCellCenters();
    cellCentersFilter.SetInputData(imageData);
    cellCentersFilter.VertexCellsOn();
    cellCentersFilter.Update();

    // Access the cell centers
    for(int i = 0; i < cellCentersFilter.GetOutput().GetNumberOfPoints(); i++)
    {
      double p[] = new double[3];
      cellCentersFilter.GetOutput().GetPoint(i, p);
      System.out.print("Point " + " " + i + " : " + " " +  p[0] + " , " + p[1] + " , " + p[2] + "\n"); 
    }

    // Display the cell centers
    vtkDataSetMapper centerMapper = new vtkDataSetMapper();
    centerMapper.SetInputConnection(cellCentersFilter.GetOutputPort());

    vtkActor centerActor = new vtkActor();
    centerActor.SetMapper(centerMapper);

    vtkDataSetMapper mapper = new vtkDataSetMapper();
    mapper.SetInputData(imageData);

    vtkActor actor = new vtkActor();
    actor.SetMapper(mapper);
    actor.GetProperty().SetRepresentationToWireframe();

    // Create the renderer, render window and interactor.
    vtkRenderer ren = new vtkRenderer();
    vtkRenderWindow renWin = new vtkRenderWindow();
    renWin.AddRenderer(ren);
    vtkRenderWindowInteractor iren = new vtkRenderWindowInteractor();
    iren.SetRenderWindow(renWin);

    // Visualize
    ren.AddActor(actor);
    ren.AddActor(centerActor);

    renWin.SetSize(300, 300);
    renWin.Render();

    iren.Initialize();
    iren.Start();
  }
}