# SpotLight

VTKExamples/Java/Lighting/SpotLight

### Description

This example places two vtkLight's with PositionalOn().

This example was inspired by Oliver Natt's question (and python script) on the VTK Users mailing list.

### Code

SpotLight.java

    import java.awt.BorderLayout;
    import java.awt.event.ActionEvent;
    import java.awt.event.ActionListener;

    import javax.swing.JButton;
    import javax.swing.JFrame;
    import javax.swing.JPanel;
    import javax.swing.SwingUtilities;

    import vtk.vtkActor;
    import vtk.vtkLight;
    import vtk.vtkNativeLibrary;
    import vtk.vtkPanel;
    import vtk.vtkPolyDataMapper;
    import vtk.vtkPlaneSource;
    import vtk.vtkNamedColors;

    public class SpotLight extends JPanel implements ActionListener {
      private static final long serialVersionUID = 1L;
      private vtkPanel renWin;
      private JButton exitButton;

      // -----------------------------------------------------------------
      // 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 SpotLight() {
        super(new BorderLayout());

        vtkNamedColors Color = new vtkNamedColors();
        //For greenLight
        double greenLightColor[] = new double[4];
        //For PinkLight
        double pinkLightColor[] = new double[4];
        //Renderer Background Color
        double BgColor[] = new double[4];
        //Renderer Background1 Color
        double BgColor2[] = new double[4];

        //Change Color Name to Use your own Color
        Color.GetColor("Lawn_green",greenLightColor);
        //Change Color Name to Use your own Color
        Color.GetColor("DeepPink",pinkLightColor);
        //Change Color Name to Use your own Color for Renderer Background
        Color.GetColor("RoyalBlue",BgColor);
        //Change Color Name to Use your own Color for Renderer Background1
        Color.GetColor("SkyBlue",BgColor2);

        vtkPlaneSource PlaneSource = new vtkPlaneSource();
        PlaneSource.SetOrigin(-5.0, 0.0, 5.0);
        PlaneSource.SetPoint1(5.0, 0.0, 5.0);
        PlaneSource.SetPoint2(-5.0, 0.0, -5.0);
        PlaneSource.SetResolution(100, 100);

        vtkPolyDataMapper Mapper = new vtkPolyDataMapper();
        Mapper.SetInputConnection(PlaneSource.GetOutputPort());

        vtkActor Actor = new vtkActor();
        Actor.SetMapper(Mapper);

        vtkLight greenLight = new vtkLight();
        greenLight.PositionalOn();
        greenLight.SetPosition(-4.0, 4.0, -1.0);
        greenLight.SetColor(greenLightColor);
        greenLight.SetIntensity(0.5);

        vtkLight pinkLight = new vtkLight();
        pinkLight.PositionalOn();
        pinkLight.SetPosition(4.0, 5.0,1.0);
        pinkLight.SetColor(pinkLightColor);
        pinkLight.SetIntensity(0.6);

        renWin = new vtkPanel();
        renWin.GetRenderer().AddActor(Actor);
        renWin.GetRenderer().SetBackground(BgColor);
        renWin.GetRenderer().SetBackground2(BgColor2);
        renWin.GetRenderer().AddLight(greenLight);
        renWin.GetRenderer().AddLight(pinkLight);
        renWin.setSize(640,480);
        renWin.resetCamera();
        renWin.GetRenderer().GetActiveCamera().Azimuth(40);
        renWin.GetRenderer().GetActiveCamera().Elevation(30);
        renWin.resetCameraClippingRange();

        // Add Java UI components
        exitButton = new JButton("Exit");
        exitButton.addActionListener(this);

        add(renWin, BorderLayout.CENTER);
        add(exitButton, BorderLayout.SOUTH);
      }

      /** An ActionListener that listens to the button. */
      public void actionPerformed(ActionEvent e) {
        if (e.getSource().equals(exitButton)) {
          System.exit(0);
        }
      }

      public static void main(String s[]) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
              JFrame frame = new JFrame("Spot Light");
              frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
              frame.getContentPane().setLayout(new BorderLayout());
              frame.getContentPane().add(new SpotLight(), BorderLayout.CENTER);
              frame.setSize(400, 400);
              frame.setLocationRelativeTo(null);
              frame.setVisible(true);
            }
          });
      }
    }