3D弹跳球动画-Java源码

import java.applet.Applet;   
import java.awt.BorderLayout;   
import java.awt.Button;   
import java.awt.GraphicsConfiguration;   
import java.awt.Panel;   
import java.awt.event.ActionEvent;   
import java.awt.event.ActionListener;   
import java.awt.event.KeyEvent;   
import java.awt.event.KeyListener;   
  
import javax.media.j3d.AmbientLight;   
import javax.media.j3d.BoundingSphere;   
import javax.media.j3d.BranchGroup;   
import javax.media.j3d.Canvas3D;   
import javax.media.j3d.DirectionalLight;   
import javax.media.j3d.Transform3D;   
import javax.media.j3d.TransformGroup;   
import javax.swing.Timer;   
import javax.vecmath.Color3f;   
import javax.vecmath.Point3d;   
import javax.vecmath.Vector3d;   
import javax.vecmath.Vector3f;   
  
import com.sun.j3d.utils.applet.MainFrame;   
import com.sun.j3d.utils.geometry.Sphere;   
import com.sun.j3d.utils.universe.SimpleUniverse;   
  
public class BouncingBall extends Applet implements ActionListener, KeyListener {   
  private Button go = new Button("Go");   
  
  private TransformGroup objTrans;   
  
  private Transform3D trans = new Transform3D();   
  
  private float height = 0.0f;   
  
  private float sign = 1.0f; // going up or down   
  
  private Timer timer;   
  
  private float xloc = 0.0f;   
  
  public BranchGroup createSceneGraph() {   
    // Create the root of the branch graph   
    BranchGroup objRoot = new BranchGroup();   
    objTrans = new TransformGroup();   
    objTrans.setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE);   
    objRoot.addChild(objTrans);   
  
    // Create a simple shape leaf node, add it to the scene graph.   
    Sphere sphere = new Sphere(0.25f);   
    objTrans = new TransformGroup();   
    objTrans.setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE);   
    Transform3D pos1 = new Transform3D();   
    pos1.setTranslation(new Vector3f(0.0f, 0.0f, 0.0f));   
    objTrans.setTransform(pos1);   
    objTrans.addChild(sphere);   
    objRoot.addChild(objTrans);   
    BoundingSphere bounds = new BoundingSphere(new Point3d(0.0, 0.0, 0.0),   
        100.0);   
  
    Color3f light1Color = new Color3f(1.0f, 0.0f, 0.2f);   
    Vector3f light1Direction = new Vector3f(4.0f, -7.0f, -12.0f);   
    DirectionalLight light1 = new DirectionalLight(light1Color,   
        light1Direction);   
    light1.setInfluencingBounds(bounds);   
    objRoot.addChild(light1);   
  
    // Set up the ambient light   
    Color3f ambientColor = new Color3f(1.0f, 1.0f, 1.0f);   
    AmbientLight ambientLightNode = new AmbientLight(ambientColor);   
    ambientLightNode.setInfluencingBounds(bounds);   
    objRoot.addChild(ambientLightNode);   
  
    return objRoot;   
  }   
  
  public BouncingBall() {   
    setLayout(new BorderLayout());   
    GraphicsConfiguration config = SimpleUniverse   
        .getPreferredConfiguration();   
    Canvas3D c = new Canvas3D(config);   
    add("Center", c);   
    c.addKeyListener(this);   
    timer = new Timer(100, this);   
    //timer.start();   
    Panel p = new Panel();   
    p.add(go);   
    add("North", p);   
    go.addActionListener(this);   
    go.addKeyListener(this);   
    // Create a simple scene and attach it to the virtual universe   
    BranchGroup scene = createSceneGraph();   
  
    SimpleUniverse u = new SimpleUniverse(c);   
    u.getViewingPlatform().setNominalViewingTransform();   
    u.addBranchGraph(scene);   
  }   
  
  public void keyPressed(KeyEvent e) {   
    //Invoked when a key has been pressed.   
    if (e.getKeyChar() == 's') {   
      xloc = xloc + .1f;   
    }   
    if (e.getKeyChar() == 'a') {   
      xloc = xloc - .1f;   
    }   
  }   
  
  public void keyReleased(KeyEvent e) {   
    // Invoked when a key has been released.   
  }   
  
  public void keyTyped(KeyEvent e) {   
    //Invoked when a key has been typed.   
  }   
  
  public void actionPerformed(ActionEvent e) {   
    // start timer when button is pressed   
    if (e.getSource() == go) {   
      if (!timer.isRunning()) {   
        timer.start();   
      }   
    } else {   
      height += .1 * sign;   
      if (Math.abs(height * 2) >= 1)   
        sign = -1.0f * sign;   
      if (height < -0.4f) {   
        trans.setScale(new Vector3d(1.0, .8, 1.0));   
      } else {   
        trans.setScale(new Vector3d(1.0, 1.0, 1.0));   
      }   
      trans.setTranslation(new Vector3f(xloc, height, 0.0f));   
      objTrans.setTransform(trans);   
    }   
  }   
  
  public static void main(String[] args) {   
    System.out.println("Program Started");   
    BouncingBall bb = new BouncingBall();   
    bb.addKeyListener(bb);   
    MainFrame mf = new MainFrame(bb, 256, 256);   
  }   
}