Java3D Picking Problem

Question

Hi, I have problem with picking. I have two shapes 3D (for example) and if there are separately (not hidden) picking is OK. But when I rotate them using myMouseRotate or rotation.rotY(angle) so one of them is hiden, it's always pick me only one of them, even it's hidden. I use pickClosest() method. What's wrong?
Please help me
pozdrawiam
Wojtek

Answer 1

It doesn't work because I need to pick one of this shape. I think that it's something with rotation... Check this simply full code below. Press any key to rotate. At the begining you pick ColorCube and it' ok. But if you rotate 180 degrees you will pick ColorCube again and it's wrong. Additionally if you change "angle = 3.14/2;" to "angle = 3*3.14/2;" you can pick Sphere but can't pick ColorCube.
How can I solve it?? Maybe when I rotate something is change with direction of pick rays.
Code - Pick_1.java:
import com.sun.j3d.utils.picking.*;
import com.sun.j3d.utils.universe.SimpleUniverse;
import com.sun.j3d.utils.geometry.*;
import javax.media.j3d.*;
import javax.vecmath.*;
import java.awt.event.*;
import java.awt.*;
import com.sun.j3d.utils.behaviors.mouse.*;
import java.util.Enumeration;
public class Pick_1 extends MouseAdapter {
     private PickCanvas pickCanvas;
     static double angle = 0.0;
     public class SimpleBehavior extends Behavior{
     private TransformGroup targetTG;
     private Transform3D rotation = new Transform3D();
     // private double angle = 0.0;
     // create SimpleBehavior
     SimpleBehavior(TransformGroup targetTG){
     this.targetTG = targetTG;
     // initialize the Behavior
     // set initial wakeup condition
     // called when behavior beacomes live
     public void initialize(){
     // set initial wakeup condition
     this.wakeupOn(new WakeupOnAWTEvent(KeyEvent.KEY_PRESSED));
     // behave
     // called by Java 3D when appropriate stimulus occures
     public void processStimulus(Enumeration criteria){
     // decode event
     // do what is necessary
     angle += 0.1;
     rotation.rotY(angle);
     targetTG.setTransform(rotation);
     //rotation.set(new Vector3f(-0.1f, 0.0f, 0.0f));
     //targetTG.setTransform(rotation);
     this.wakeupOn(new WakeupOnAWTEvent(KeyEvent.KEY_PRESSED));
     public Pick_1()
     Frame frame = new Frame("Box and Sphere");
     GraphicsConfiguration config = SimpleUniverse.getPreferredConfiguration();
     Canvas3D canvas = new Canvas3D(config);
     canvas.setSize(400, 400);
     SimpleUniverse universe = new SimpleUniverse(canvas);
     BranchGroup group = new BranchGroup();
          TransformGroup objTransform = new TransformGroup();     
     objTransform.setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE);
     objTransform.setCapability(TransformGroup.ALLOW_TRANSFORM_READ);
     group.addChild(objTransform);     
     /*      MouseRotate myMouseRotate = new MouseRotate();
     myMouseRotate.setTransformGroup(objTransform);
     myMouseRotate.setSchedulingBounds(new BoundingSphere());
     group.addChild(myMouseRotate);
     MouseTranslate myMouseTranslate = new MouseTranslate();
     myMouseTranslate.setTransformGroup(objTransform);
     myMouseTranslate.setSchedulingBounds(new BoundingSphere());
     group.addChild(myMouseTranslate);
     MouseZoom myMouseZoom = new MouseZoom();
     myMouseZoom.setTransformGroup(objTransform);
     myMouseZoom.setSchedulingBounds(new BoundingSphere());
     group.addChild(myMouseZoom);
     SimpleBehavior myRotationBehavior = new SimpleBehavior(objTransform);
     myRotationBehavior.setSchedulingBounds(new BoundingSphere());
          group.addChild(myRotationBehavior);
     //create a sphere
     Vector3f vector2 = new Vector3f(0.6f, 0.0f, 0.0f);
     Transform3D transform2 = new Transform3D();
     transform2.setTranslation(vector2);
     TransformGroup transformGroup2 = new TransformGroup(transform2);
     Appearance appearance = new Appearance();
     appearance.setPolygonAttributes(
     new PolygonAttributes(PolygonAttributes.POLYGON_LINE,
     PolygonAttributes.CULL_BACK,0.0f));
     Sphere sphere = new Sphere(0.1f,appearance);
     transformGroup2.addChild(sphere);
     objTransform.addChild(transformGroup2);
     // create a color cube
     Vector3f vector = new Vector3f(0.3f, 0.0f, 0.0f);
     Transform3D transform = new Transform3D();
     transform.setTranslation(vector);
     TransformGroup transformGroup = new TransformGroup(transform);
     ColorCube cube = new ColorCube(0.1);
     transformGroup.addChild(cube);
     objTransform.addChild(transformGroup);
     //dodatkowo przesuniecie od razu o 90 stopni
          Transform3D obrot = new Transform3D();
               angle = 3.14/2;
          obrot.rotY(angle);                                   //!!!!! takie przesuniecie dobrze dziala
     objTransform.setTransform(obrot);                //WIEC O CO CHODZI!!!!!!!!!!!!!!!
     universe.getViewingPlatform().setNominalViewingTransform();
     universe.addBranchGraph(group);
     frame.addWindowListener(new WindowAdapter() {
     public void windowClosing(WindowEvent winEvent) {
     System.exit(0);
     frame.add(canvas);
     pickCanvas = new PickCanvas(canvas, group);
     pickCanvas.setMode(PickCanvas.BOUNDS);
     canvas.addMouseListener(this);
     frame.pack();
     frame.show();
     public static void main( String[] args ) {
     new Pick_1();
     public void mouseClicked(MouseEvent e)
     pickCanvas.setShapeLocation(e);
     PickResult result = pickCanvas.pickClosest();
     if (result == null) {
     System.out.println("Nothing picked");
     } else {
     Primitive p = (Primitive)result.getNode(PickResult.PRIMITIVE);
     Shape3D s = (Shape3D)result.getNode(PickResult.SHAPE3D);
     if (p != null) {
     System.out.println(p.getClass().getName());
     } else if (s != null) {
     System.out.println(s.getClass().getName());
     } else{
     System.out.println("null");
     /*pickCanvas.setShapeLocation(e);
     PickResult result = pickCanvas.pickClosest();
     if (result == null) {
     System.out.println("Nothing picked");
     } else {
     // PickIntersection pi = result.getClosestIntersection(
     pickCanvas.getStartPosition();
     Shape3D s = (Shape3D)result.getNode(PickResult.SHAPE3D);
     System.out.println(s.getClass().getName());
} // end of class Pick