cone5.java

a very goog book

//
// This example introduces the concepts of user interaction with VTK.
// First, a different interaction style (than the default) is defined.
// Second, the interaction is started. 
//
//

// we import the vtk wrapped classes forst
import vtk.*;

// then we define our class
public class Cone5 {
  // in the static contructor we load in the native code
  // The libraries must be in your path to work
  static { 
    System.loadLibrary("vtkCommonJava"); 
    System.loadLibrary("vtkFilteringJava"); 
    System.loadLibrary("vtkIOJava"); 
    System.loadLibrary("vtkImagingJava"); 
    System.loadLibrary("vtkGraphicsJava"); 
    System.loadLibrary("vtkRenderingJava"); 
  }

  // now the main program
  public static void main (String []args) throws Exception {
    // 
    // 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.SetInput(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 add our two renderers into the render window using AddRenderer. We also
    // set the size to be 600 pixels by 300.
    //
    vtkRenderWindow renWin = new vtkRenderWindow();
    renWin.AddRenderer( ren1 );
    renWin.SetSize(300, 300);
    
    //
    // Make one camera view 90 degrees from other.
    //
    ren1.GetActiveCamera().Azimuth(90);
    
    // 
    // 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);

    //
    // Unlike the previous examples where we performed some operations and then
    // exited, here we leave an event loop running. The user can use the mouse
    // and keyboard to perform the operations on the scene according to the
    // current interaction style.
    //
    
    //
    // Initialize and start the event loop. Once the render window appears,
    // mouse in the window to move the camera. The Start() method executes
    // an event loop which listens to user mouse and keyboard events. Note
    // that keypress-e exits the event loop. (Look in vtkInteractorStyle.h
    // for a summary of events, or the appropriate Doxygen documentation.)
    //
    iren.Initialize();
    iren.Start();
  }
}