Hi Gary,

It looks like you found a bug in our code.  The only workaround I can
suggest is to try using WakeupOnActivation/Deactivation and use the
scheduling bounds of the behavior as your collision bounds.  I attached
a modified HelloUniverse that does this.

Doug Twilleager
Java 3D Team


> Mime-Version: 1.0
> Content-Transfer-Encoding: 7bit
> Content-Description: Memo
> Subject: [JAVA3D] WakeUpOnViewPlatformEntry only fires one time!
> To: [EMAIL PROTECTED]
>
> Hello,
>
>  I've seen no response to my question.  Has anyone here gotten
> WakeupOnViewPlatformEntry to work?
>
> Thanks,
> -Gary
> ---------------------- Forwarded by Gary Moss/arl on 07/28/99 12:15 PM
> ---------------------------
>
>
> "Gary S. Moss" <[EMAIL PROTECTED]> on 07/22/99 04:58:15 PM
> To: [EMAIL PROTECTED]
> cc:  (bcc: Gary Moss/arl)
> Subject: [JAVA3D] WakeUpOnViewPlatformEntry only fires one time!
>
>
> Hello,
>
>  I finally got around to messing with collision detection between my view
> platform and scene.  Everything works the first time the view platform
> collides, I get a WakeupOnViewPlatformEntry and corresponding Exit when
> appropriate.   However subsequently I can never seem to get another Entry,
> though Exit fires consistently.   I vaguely remember reading about a similar
> problem on this list, but don't recall whether it was a bug in J3d or operator
> error.  I am using JDK 1.2.2 and Java3d 1.1.2 OpenGl under WinNT 4.0 SP5.   My
> code follows (my apologies if tabs get farbled in translation):
>
> TIA,
> -Gary
>
> --
> import java.util.*;
> import javax.media.j3d.*;
>
> public class CollisionBehavior extends Behavior
>  {
>  private WakeupCondition criterion;
>    private Bounds bounds;
>    private boolean collided;
>
>  public CollisionBehavior( Bounds bnds )
>   {
>   super();
>   this.bounds = bnds;
>       collided = false;
>       //System.err.println( "CollisonBehavior( " + bnds + " )" );
>   }
>
>  public void initialize()
>   {
>   WakeupCriterion[] allEvents = new WakeupCriterion[2];
>    allEvents[0] = new WakeupOnViewPlatformEntry( bounds );
>     allEvents[1] = new WakeupOnViewPlatformExit( bounds );
>   criterion = new WakeupOr( allEvents );
>   wakeupOn( criterion );
>   }
>
>  public void processStimulus( Enumeration criteria )
>   {
>   WakeupCriterion wakeup;
>
>   while( criteria.hasMoreElements() )
>    {
>    wakeup = (WakeupCriterion) criteria.nextElement();
>
>    if( wakeup instanceof WakeupOnViewPlatformEntry )
>     {
>            System.err.println( "Entered View Platform" );
>             collided = true;
>     }
>          else
>          if( wakeup instanceof WakeupOnViewPlatformExit )
>             {
>             System.err.println( "Exited View Platform" );
>             collided = false;
>             }
>    }
>   wakeupOn( criterion );
>   }
>
>   public boolean IsCollided()
>     {
>     return collided;
>     }
>   }
>
> ===========================================================================
> To unsubscribe, send email to [EMAIL PROTECTED] and include in the body
> of the message "signoff JAVA3D-INTEREST".  For general help, send email to
> [EMAIL PROTECTED] and include in the body of the message "help".
>
> ===========================================================================
> To unsubscribe, send email to [EMAIL PROTECTED] and include in the body
> of the message "signoff JAVA3D-INTEREST".  For general help, send email to
> [EMAIL PROTECTED] and include in the body of the message "help".
/*
 *      %Z%%M% %I% %E% %U%
 *
 * Copyright (c) 1996-1998 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Sun grants you ("Licensee") a non-exclusive, royalty free, license to use,
 * modify and redistribute this software in source and binary code form,
 * provided that i) this copyright notice and license appear on all copies of
 * the software; and ii) Licensee does not utilize the software in a manner
 * which is disparaging to Sun.
 *
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING ANY
 * IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR
 * NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE
 * LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING
 * OR DISTRIBUTING THE SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS
 * LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT,
 * INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER
 * CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF
 * OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 *
 * This software is not designed or intended for use in on-line control of
 * aircraft, air traffic, aircraft navigation or aircraft communications; or in
 * the design, construction, operation or maintenance of any nuclear
 * facility. Licensee represents and warrants that it will not use or
 * redistribute the Software for such purposes.
 */

import java.applet.Applet;
import java.awt.BorderLayout;
import java.awt.event.*;
import java.awt.GraphicsConfiguration;
import com.sun.j3d.utils.applet.MainFrame;
import com.sun.j3d.utils.geometry.ColorCube;
import com.sun.j3d.utils.universe.*;
import javax.media.j3d.*;
import javax.vecmath.*;
import com.sun.j3d.utils.behaviors.keyboard.*;
import java.util.Enumeration;

public class HelloUniverse extends Applet {

    public class CollisionBehavior extends Behavior
    {
        private WakeupCondition criterion;
        private Bounds bounds;
        private boolean collided;

        public CollisionBehavior( Bounds bnds )
        {
            super();
            this.bounds = bnds;
            collided = false;
            //System.err.println( "CollisonBehavior( " + bnds + " )" );
        }

        public void initialize()
        {
            WakeupCriterion[] allEvents = new WakeupCriterion[2];
            allEvents[0] = new WakeupOnActivation();
            allEvents[1] = new WakeupOnDeactivation();
            criterion = new WakeupOr( allEvents );
            wakeupOn( criterion );
        }

        public void processStimulus( Enumeration criteria )
        {
            WakeupCriterion wakeup;

            while( criteria.hasMoreElements() )
                {
                    wakeup = (WakeupCriterion) criteria.nextElement();

                    if( wakeup instanceof WakeupOnActivation)
                        {
                            System.err.println( "Entered View Platform" );
                            collided = true;
                        }
                    else
                        if( wakeup instanceof WakeupOnDeactivation )
                            {
                                System.err.println( "Exited View Platform" );
                                collided = false;
                            }
                }
            wakeupOn( criterion );
        }

        public boolean IsCollided()
        {
            return collided;
        }
    }

    public BranchGroup createSceneGraph() {
        // Create the root of the branch graph
        BranchGroup objRoot = new BranchGroup();

        // Create the transform group node and initialize it to the
        // identity.  Enable the TRANSFORM_WRITE capability so that
        // our behavior code can modify it at runtime.  Add it to the
        // root of the subgraph.
        TransformGroup objTrans = new TransformGroup();
        objTrans.setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE);
        objRoot.addChild(objTrans);

        // Create a simple shape leaf node, add it to the scene graph.
        objTrans.addChild(new ColorCube(0.4));

        // Create a new Behavior object that will perform the desired
        // operation on the specified transform object and add it into
        // the scene graph.
        Transform3D yAxis = new Transform3D();
        Alpha rotationAlpha = new Alpha(-1, Alpha.INCREASING_ENABLE,
                                        0, 0,
                                        4000, 0, 0,
                                        0, 0, 0);

        RotationInterpolator rotator =
            new RotationInterpolator(rotationAlpha, objTrans, yAxis,
                                     0.0f, (float) Math.PI*2.0f);
        BoundingSphere bounds =
            new BoundingSphere(new Point3d(0.0,0.0,0.0), 100.0);
        rotator.setSchedulingBounds(bounds);
        objTrans.addChild(rotator);

        // Have Java 3D perform optimizations on this scene graph.
        objRoot.compile();

        return objRoot;
    }

    public HelloUniverse() {
        setLayout(new BorderLayout());
        GraphicsConfiguration config =
           SimpleUniverse.getPreferredConfiguration();

        Canvas3D c = new Canvas3D(config);
        add("Center", c);

        // Create a simple scene and attach it to the virtual universe
        BranchGroup scene = createSceneGraph();
        SimpleUniverse u = new SimpleUniverse(c);
        u.getViewingPlatform().getViewPlatform().setActivationRadius(0.3f);

        // This will move the ViewPlatform back a bit so the
        // objects in the scene can be viewed.
        u.getViewingPlatform().setNominalViewingTransform();

        BranchGroup b = new BranchGroup();
        KeyNavigatorBehavior key = new 
KeyNavigatorBehavior(u.getViewingPlatform().getViewPlatformTransform());
        key.setSchedulingBounds(new BoundingSphere(new Point3d(0.0, 0.0, 0.0),
                                                   100000.0));
        b.addChild(key);

        BoundingSphere bnd = new BoundingSphere(new Point3d(0.0, 0.0, 0.0), 0.5);
        CollisionBehavior coll = new CollisionBehavior(bnd);
        coll.setSchedulingBounds(bnd);
        b.addChild(coll);

        u.addBranchGraph(scene);
        u.addBranchGraph(b);
    }

    //
    // The following allows HelloUniverse to be run as an application
    // as well as an applet
    //
    public static void main(String[] args) {
        new MainFrame(new HelloUniverse(), 256, 256);
    }
}

Reply via email to