// WrapParticles3D.java// Andrew Davison, April 2005, ad@fivedots.coe.psu.ac.th/* Three different implementations of Particle systems:      * points in a PointArray      * lines in a LineArray      * quads in a QuadArray   Geometrries are stored using BY_REFERENCE, and updated with   a GeometryUpdater subclass.   The QuadArray example illustrates how to apply a single texture    to each of the quads, and how to blend texture and colour.   The examples are all variations on a fountain of particles    emmitted from the origin in a parabolic arc. Particles are    reused when they drop below the XZ plane.*/import javax.swing.*;import java.awt.*;import com.sun.j3d.utils.universe.*;import com.sun.j3d.utils.geometry.*;import javax.media.j3d.*;import javax.vecmath.*;import com.sun.j3d.utils.behaviors.vp.*;public class WrapParticles3D extends JPanel// Holds the 3D canvas where the loaded image is displayed{  private static final int PWIDTH = 512;   // size of panel  private static final int PHEIGHT = 512;   private static final int BOUNDSIZE = 100;  // larger than world  private static final Point3d USERPOSN = new Point3d(0,5,20);    // initial user position  private SimpleUniverse su;  private BranchGroup sceneBG;  private BoundingSphere bounds;   // for environment nodes  public WrapParticles3D(int numParticles, int fountainChoice)  // construct the 3D canvas  {    setLayout( new BorderLayout() );    setOpaque( false );    setPreferredSize( new Dimension(PWIDTH, PHEIGHT));    GraphicsConfiguration config =					SimpleUniverse.getPreferredConfiguration();    Canvas3D canvas3D = new Canvas3D(config);    add("Center", canvas3D);    canvas3D.setFocusable(true);    canvas3D.requestFocus();    // the canvas now has focus, so receives key events    su = new SimpleUniverse(canvas3D);    createSceneGraph(numParticles, fountainChoice);    initUserPosition();        // set user's viewpoint    orbitControls(canvas3D);   // controls for moving the viewpoint        su.addBranchGraph( sceneBG );  } // end of WrapParticles3D()  private void createSceneGraph(int numParts, int fountainChoice)   // initilise the scene  {     sceneBG = new BranchGroup();    bounds = new BoundingSphere(new Point3d(0,0,0), BOUNDSIZE);       lightScene();         // add the lights    addBackground();      // add the sky    sceneBG.addChild( new CheckerFloor().getBG() );  // add the floor    switch(fountainChoice) {      case 1: addPointsFountain(numParts); break;      case 2: addLinesFountain(numParts); break;      case 3: addQuadFountain(numParts); break;      default: break;   // say nothing    }    sceneBG.compile();   // fix the scene  } // end of createSceneGraph()  private void lightScene()  /* One ambient light, 2 directional lights */  {    Color3f white = new Color3f(1.0f, 1.0f, 1.0f);    // Set up the ambient light    AmbientLight ambientLightNode = new AmbientLight(white);    ambientLightNode.setInfluencingBounds(bounds);    sceneBG.addChild(ambientLightNode);    // Set up the directional lights    Vector3f light1Direction  = new Vector3f(-1.0f, -1.0f, -1.0f);       // left, down, backwards     Vector3f light2Direction  = new Vector3f(1.0f, -1.0f, 1.0f);       // right, down, forwards    DirectionalLight light1 =             new DirectionalLight(white, light1Direction);    light1.setInfluencingBounds(bounds);    sceneBG.addChild(light1);    DirectionalLight light2 =         new DirectionalLight(white, light2Direction);    light2.setInfluencingBounds(bounds);    sceneBG.addChild(light2);  }  // end of lightScene()  private void addBackground()  // A blue sky  { Background back = new Background();    back.setApplicationBounds( bounds );    back.setColor(0.17f, 0.65f, 0.92f);    // sky colour    sceneBG.addChild( back );  }  // end of addBackground()  private void orbitControls(Canvas3D c)  /* OrbitBehaviour allows the user to rotate around the scene, and to     zoom in and out.  */  { OrbitBehavior orbit = 		new OrbitBehavior(c, OrbitBehavior.REVERSE_ALL);    orbit.setSchedulingBounds(bounds);    ViewingPlatform vp = su.getViewingPlatform();    vp.setViewPlatformBehavior(orbit);	      }  // end of orbitControls()  private void initUserPosition()  // Set the user's initial viewpoint using lookAt()  {    ViewingPlatform vp = su.getViewingPlatform();    TransformGroup steerTG = vp.getViewPlatformTransform();    Transform3D t3d = new Transform3D();    steerTG.getTransform(t3d);    // args are: viewer posn, where looking, up direction    t3d.lookAt( USERPOSN, new Point3d(0,0,0), new Vector3d(0,1,0));    t3d.invert();    steerTG.setTransform(t3d);  }  // end of initUserPosition()// -------------------------- fountains -------------  private void addPointsFountain(int numParts)  {    PointParticles ptsFountain = new PointParticles(numParts, 20);   // time delay    // move particles start position to (2,0,1)    TransformGroup posnTG = new TransformGroup();    Transform3D trans = new Transform3D();    trans.setTranslation( new Vector3d(2.0f, 0.0f, 1.0f) );    posnTG.setTransform(trans);    posnTG.addChild(ptsFountain);     sceneBG.addChild( posnTG );    // timed behaviour to animate the fountain    Behavior partBeh = ptsFountain.getParticleBeh();    partBeh.setSchedulingBounds( bounds );    sceneBG.addChild(partBeh);  } // end of addPointsFountain()  private void addQuadFountain(int numParts)  {    QuadParticles quadsFountain = new QuadParticles(numParts, 20);   // time delay    sceneBG.addChild(quadsFountain);   // will start at origin    // timed behaviour to animate the fountain    Behavior partBeh = quadsFountain.getParticleBeh();    partBeh.setSchedulingBounds( bounds );    sceneBG.addChild(partBeh);  } // end of addQuadFountain()  private void addLinesFountain(int numParts)  {    LineParticles linesFountain = 				new LineParticles(numParts, 20);   // time delay    sceneBG.addChild(linesFountain);   // will start at origin    // timed behaviour to animate the fountain    Behavior partBeh = linesFountain.getParticleBeh();    partBeh.setSchedulingBounds( bounds );    sceneBG.addChild(partBeh);  } // end of addLinesRefFountain()} // end of WrapParticles3D class