That time has come once again...:-)
When will the 1.2.1 beta OpenGL or DirectX be released?
Kelvin Chung wrote:
> Hi,
>
> >When do you expect a bug-fix version of 1.2 Beta for DirectX ?
> >There are some bugs, i.e.
> >4309059 background geometry appears very close to the camera vs 1.1.3
> >(....in 1.2, too !!!)
> >4328532 Textures for the bottom of cones and cylinders are upside-down
> >4332793 View transform & object transform not synchronized in a single
> >behavior
> >which make working really hurting :-(
> >
>
> The above bugs is not specific to DirectX version,
> it occurs in OpenGL version also.
>
> The first two bugs will be fixed in next
> Java3D v1.2.1 beta release.
>
> The last one is not a bug, please see the following
> message.
>
> Thanks.
>
> - Kelvin
> -----------------
> Java 3D Team
> Sun Microsystems Inc.
>
> > ------------- Begin Forwarded Message -------------
> >
> > Date: Mon, 26 Jun 2000 18:32:08 -0700 (PDT)
> > From: Kelvin Chung <tlchung@ha3mpk>
> > Subject: Re: View and Scene synchronization bug
> > To: [EMAIL PROTECTED], [EMAIL PROTECTED], [EMAIL PROTECTED]
> > Cc: www.manning.com/barrilleaux
> > Mime-Version: 1.0
> >
> > Hi,
> >
> > To better understand this problem, let's take a look at
> > the simply version has only one behavior to both rotate
> > the cube and modify the camera viewpoint so that
> > we expect the cube appear stationary. This example is modify
> > from HelloUniverse example.
> >
> > If we write the behavior in this way :
> >
> > public void processStimulus(Enumeration criteria) {
> > Modify Camera View point using the object transform
> > Modify Object transform as in RotationInterpolator
> > }
> >
> > Using J3D v1.2 we will see the cube jitters
> > (more serious under windows than solaris).
> >
> > However if we write the behavior in this way :
> >
> >
> > public void processStimulus(Enumeration criteria) {
> > Modify Object transform as in RotationInterpolator
> > Modify Camera View point using object transform
> >
> > }
> >
> > There is NO jitter at all under both platform.
> >
> > In fact you will also see the cube jitter
> > when using J3D 1.1.3 under windows.
> >
> > This is not a bug. Here is the explanation :
> >
> > -------------------
> > The object transform that that camera view point get is
> > ONE frame before what RotationInterpolator is about to
> > be set. If the timing of frame is equal between every
> > successive processStimulus() invocation. Then the
> > different between the alpha values of rotation interpolator
> > get from one frame to another should be the same and you
> > will always see the same offset from the camera to the cube.
> > i.e. the cube appear did not move at all without any jitter.
> >
> > However, in reality the interval processStimulus() is invoked
> > is not exactly the same from frame to frame. It all depends
> > on the OS scheduling. So the offset of view from camera to
> > the cube may varies from frame to frame and you will see the
> > cube jitters all the time. This phenomenon is more obvious
> > under windows than sparc solaris - the later has finer time
> > resolution and better scheduling. Thats why you may
> > see the program run fine under solaris but jitter under windows.
> >
> > To solve the problem, the user behavior has to ganrantee
> > that the transform set by the camera and the cube are the
> > in sync by putting them in a single behaviors and same
> > transform is apply to interpolators first if it is need
> > to compute the camera viewpoint.
> >
> > --------------
> >
> > In the two example programs given (attach in the email),
> > there are two behaviors :
> >
> > (A) Modify the object transformation matrix using some
> > kinds of Interpolator.
> > (B) Read back the transform matrix (which is modify by A)
> > and use it to transform camea under View
> >
> > If behavior A is always schedule to run before behavior B
> > in Java3D, you will not see any jitter. However there is
> > no gaurantee for the order of behaviors execute under Java3D.
> > So you may see (A) run before (B) or (B) run befores (A)
> > or (A)&(B) may run in parallel if there are two CPU in your system.
> >
> > Currently there is no API to gaurantee order of behaviors running
> > in Java3D. The solution is to make sure if camera viewpoint
> > transformation matrix depends on result of other behaviors,
> > we should put them in a single behavior to sync both
> > transform.
> >
> > Attach is a program modify from the original CameraFollow
> > behavior to see how it works. Running this program in
> > both windows & solaris and you wouldn't see the jitter.
> >
> > Thanks.
> >
> > - Kelvin
> > -----------------
> > Java 3D Team
> > Sun Microsystems Inc.
>
> import javax.vecmath.*;
> > import javax.media.j3d.*;
> > import java.util.*;
> >
> > /*
> > This class is a behavior that is meant to be used for creating
> > a "following" camera effect.
> > Every update (elapsed frame 0) it copies and store the targets matrix
> > in a buffer, then sets it own tranform from the end of the buffer.
> > The effect is a view chasing or following of the target transform.
> > However, if the buffer size is set to 1, then the offset is the only
> > difference between the target transform and the output transfrom
> > */
> >
> > public class CameraFollow extends Behavior
> > {
> > WakeupCondition wake = new WakeupOnElapsedFrames(0);
> > public TransformGroup targetTG = null;
> > public TransformGroup cameraTG = null;
> > Transform3D tr3d = new Transform3D();
> > Matrix4d offsetMat = new Matrix4d();
> > final int MAX_BUFFER = 1;
> > Matrix4d[] mat = new Matrix4d[MAX_BUFFER];
> >
> > int queueCount = 0;
> > int lagCount = 0;
> > Alpha alpha;
> > Transform3D axis = new Transform3D();
> > Transform3D axisInverse = new Transform3D();
> > TransformGroup target;
> > float minimumAngle ;
> > float maximumAngle ;
> >
> > Transform3D rotation = new Transform3D();
> > Transform3D temp = new Transform3D();
> >
> > public CameraFollow(TransformGroup objTrans) {
> > super();
> > target = objTrans;
> > alpha = new Alpha(-1, Alpha.INCREASING_ENABLE,
> > 0, 0,
> > 4000, 0, 0,
> > 0, 0, 0);
> > axisInverse.invert(axis);
> > minimumAngle = 0.0f;
> > maximumAngle = (float) (Math.PI*2.0f);
> >
> > }
> >
> > public void initialize()
> > {
> > for ( int i = 0; i<MAX_BUFFER ; i++ )
> > {
> > mat[i] = new Matrix4d();
> > mat[i].setIdentity();
> > }
> > offsetMat.setIdentity();
> > offsetMat.setTranslation( new Vector3d( 0.0f, 0.5f, 3.0f ) );
> > wakeupOn(wake);
> >
> > }
> >
> > public void processStimulus(Enumeration criteria)
> > {
> >
> > // Perform the function of RotationInterpolator
> > if (alpha != null) {
> > float value = this.alpha.value();
> > double val = (1.0-value)*minimumAngle + value*maximumAngle;
> > /* construct a Transform3D from: axis * rotation * axisInverse
> */
> > rotation.rotY(val);
> >
> > temp.mul(axis, rotation);
> > temp.mul(temp, axisInverse);
> >
> > target.setTransform(temp);
> > }
> >
> >
> >
> > // Transform the Camera view point
> > if ( cameraTG != null )
> > {
> > if ( targetTG != null )
> > {
> > targetTG.getTransform(tr3d);
> >
> > // Copy the targets matrix to the buffer
> > tr3d.get(mat[queueCount]);
> >
> > //lagCount = queueCount + 1;
> > //if ( lagCount >= MAX_BUFFER )
> > // lagCount = 0;
> >
> > // Multiple in the view offset
> > mat[lagCount].mul( offsetMat );
> >
> > tr3d.set(mat[lagCount]);
> >
> > // Finally, set the transfrom above the ViewPlatform
> > cameraTG.setTransform( tr3d );
> >
> > //queueCount++;
> > //if ( queueCount >= MAX_BUFFER )
> > // queueCount = 0;
> > }
> > }
> >
> > wakeupOn(wake);
> > }
> > }
> >
> > ----------------------------------------------------------------------
> > /*
> > * @(#)HelloUniverse.java 1.47 99/09/15 13:36:59
> > *
> > * Copyright (c) 1996-1999 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.*;
> >
> > public class HelloUniverse extends Applet {
> > CameraFollow cfb;
> >
> > 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);
> > objTrans.setCapability(TransformGroup.ALLOW_TRANSFORM_READ);
> >
> > // Create a simple shape leaf node, add it to the scene graph.
> > objTrans.addChild(new ColorCube(0.4));
> >
> > BoundingSphere bounds =
> > new BoundingSphere(new Point3d(0.0,0.0,0.0), 100.0);
> >
> > // 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);
> > rotator.setSchedulingBounds(bounds);
> > objTrans.addChild(rotator);
> > */
> > // added by SFK
> > cfb = new CameraFollow(objTrans);
> > cfb.targetTG = objTrans;
> > // cfb.cameraTG = cameraTG;
> > cfb.setSchedulingBounds(bounds);
> > objTrans.addChild(cfb);
> > // end added by SFK
> >
> > // 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);
> >
> > // added by SFK
> > cfb.cameraTG =
> u.getViewingPlatform().getMultiTransformGroup().getTransformGroup(0);
> > // end added by SFK
> >
> > // This will move the ViewPlatform back a bit so the
> > // objects in the scene can be viewed.
> > u.getViewingPlatform().setNominalViewingTransform();
> >
> > u.addBranchGraph(scene);
> > }
> >
> > //
> > // 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);
> > }
> > }
>
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--
___________________________________________________________
Shawn Kendall Full Sail Real World Education
Course Director 3300 University BLVD
Real Time 3D for Gaming Winter Park FL 32792
[EMAIL PROTECTED] http://www.fullsail.com
___________________________________________________________
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To unsubscribe, send email to [EMAIL PROTECTED] and include in the body
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