Cone6

VTKExamples/Java/Rendering/Cone6


Question

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Code

Cone6.java

import vtk.vtkActor;
import vtk.vtkBoxWidget;
import vtk.vtkConeSource;
import vtk.vtkInteractorStyleTrackballCamera;
import vtk.vtkNativeLibrary;
import vtk.vtkPolyDataMapper;
import vtk.vtkRenderer;
import vtk.vtkRenderWindow;
import vtk.vtkRenderWindowInteractor;
import vtk.vtkTransform;

// For writing an image
import vtk.vtkPNGWriter;
import vtk.vtkWindowToImageFilter;

public class Cone6 {
  private static final long serialVersionUID = 1L;

  /**
   * @param args
   */
  // load the necessary interface libraries on first reference to the 
  // class.
  // Loading Native Libraries.
  // Now it works in eclipse without any issues.
  static {
    if (!vtkNativeLibrary.LoadAllNativeLibraries()) {
      for (vtkNativeLibrary lib : vtkNativeLibrary.values()) {
        if (!lib.IsLoaded()) {
          System.out.println(lib.GetLibraryName() + " not loaded");
        }
      }
    }
    vtkNativeLibrary.DisableOutputWindow(null);
  }

  // create the box widget as an instance variable so we can interact
  // with it from the interaction call back. 
  vtkBoxWidget boxWidget = null;

  public static void main(String[] args) {
    // We will start by creating an instance of our Cone6 example
    // This example uses callbacks, and for Java that requires an instance
    // object to own the callback logic.

    Cone6 myCone = new Cone6();
    myCone.doit();
  }

  // Similar to Step2/Java/Cone2.java, we define a callback for
  // interaction. In this case we will apply the box transform to the its prop3D. 
  // Java callbacks do not have parameters. 
  void myCallback() {
    vtkTransform t = new vtkTransform();
    boxWidget.GetTransform(t);
    boxWidget.GetProp3D().SetUserTransform(t);
  }

  /*
   * The doit() function is simply the instance function to perform the
   * construction of the vtk pipeline for this example.
   */
  void doit() {

    // This example introduces 3D widgets. 3D widgets take advantage of the
    // event/observer design pattern introduced previously. They typically
    // have a particular representation in the scene which can be
    // interactively
    // selected and manipulated using the mouse and keyboard. As the widgets
    // are manipulated, they in turn invoke events such as
    // StartInteractionEvent,
    // InteractionEvent, and EndInteractionEvent which can be used to
    // manipulate
    // the scene that the widget is embedded in. 3D widgets work in the
    // context
    // of the event loop which was set up in the previous example.
    //

    // Next we create an instance of vtkConeSource and set some of its
    // properties. The instance of vtkConeSource "cone" is part of a
    // visualization pipeline (it is a source process object); it produces
    // data (output type is vtkPolyData) which other filters may process.
    vtkConeSource cone = new vtkConeSource();
    cone.SetHeight(3.0);
    cone.SetRadius(1.0);
    cone.SetResolution(10);

    // In this example we terminate the pipeline with a mapper process
    // object.
    // (Intermediate filters such as vtkShrinkPolyData could be inserted in
    // between the source and the mapper.) We create an instance of
    // vtkPolyDataMapper to map the polygonal data into graphics primitives.
    // We
    // connect the output of the cone souece to the input of this mapper.
    vtkPolyDataMapper coneMapper = new vtkPolyDataMapper();
    coneMapper.SetInputData(cone.GetOutput());

    // Create an actor to represent the cone. The actor orchestrates
    // rendering of
    // the mapper's graphics primitives. An actor also refers to properties
    // via a
    // vtkProperty instance, and includes an internal transformation matrix.
    // We
    // set this actor's mapper to be coneMapper which we created above.
    vtkActor coneActor = new vtkActor();
    coneActor.SetMapper(coneMapper);

    // Create the Renderer and assign actors to it. A renderer is like a
    // viewport. It is part or all of a window on the screen and it is
    // responsible for drawing the actors it has. We also set the
    // background color here.
    vtkRenderer ren1 = new vtkRenderer();
    ren1.AddActor(coneActor);
    ren1.SetBackground(0.1, 0.2, 0.4);

    // Finally we create the render window which will show up on the screen
    // We put our renderer into the render window using AddRenderer. We
    // also set the size to be 300 pixels by 300.
    vtkRenderWindow renWin = new vtkRenderWindow();
    renWin.AddRenderer(ren1);
    renWin.SetSize(300, 300);

    // The vtkRenderWindowInteractor class watches for events (e.g.,
    // keypress,
    // mouse) in the vtkRenderWindow. These events are translated into
    // event invocations that VTK understands (see VTK/Common/vtkCommand.h
    // for all events that VTK processes). Then observers of these VTK
    // events can process them as appropriate.
    vtkRenderWindowInteractor iren = new vtkRenderWindowInteractor();
    iren.SetRenderWindow(renWin);

    // By default the vtkRenderWindowInteractor instantiates an instance
    // of vtkInteractorStyle. vtkInteractorStyle translates a set of events
    // it observes into operations on the camera, actors, and/or properties
    // in the vtkRenderWindow associated with the vtkRenderWinodwInteractor.
    // Here we specify a particular interactor style.
    vtkInteractorStyleTrackballCamera style = new vtkInteractorStyleTrackballCamera();
    iren.SetInteractorStyle(style);


    // Here we use a vtkBoxWidget to transform the underlying coneActor (by
    // manipulating its transformation matrix). Many other types of widgets
    // are available for use, see the documentation for more details.
    //
    // The SetInteractor method is how 3D widgets are associated with the
    // render
    // window interactor. Internally, SetInteractor sets up a bunch of
    // callbacks
    // using the Command/Observer mechanism (AddObserver()). The place
    // factor
    // controls the initial size of the widget with respect to the bounding
    // box
    // of the input to the widget.
    boxWidget = new vtkBoxWidget();
    boxWidget.SetInteractor(iren);
    boxWidget.SetPlaceFactor(1.25);

    // Place the interactor initially. The input to a 3D widget is used to
    // initially position and scale the widget. The EndInteractionEvent is
    // observed which invokes the SelectPolygons callback.
    boxWidget.SetProp3D(coneActor);
    boxWidget.PlaceWidget();

    // Now for every interaction event that is generated by the boxWidget,
    // call our callback function.
    boxWidget.AddObserver("InteractionEvent", this, "myCallback");

    // Normally the user presses the "i" key to bring a 3D widget to
    // life. Here we will manually enable it so it appears with the cone.
    boxWidget.On();

    // Start the event loop.
    iren.Initialize();
    renWin.Render();
    iren.Start();

    // There is no explicit need to free any objects at this point.
    // Once Java exits, memory is automatically freed.

  }


}