We have fixed quite a few state update bugs in 1.1.1. Some are related to
multiple views, some are not. It would be near impossible for us to look
at our fixes and say that they fix the problems you are seeing. If we had
a test case of the paticular failure, then we could verify it. The buglist
will get updated when we release 1.1.1. We could look into updating the
known bugs list more often.
Doug.
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> To: Doug Twilleager <Doug.Twilleager@Eng>
> CC: [EMAIL PROTECTED], [EMAIL PROTECTED]
> Subject: Re: [java3d] view to world transform jitters
> Content-Transfer-Encoding: 7bit
>
> Of course, in the meantime, it would be much appreciated if you guys
> go back over your multi-view fix to see if it would cure jitter
> problems that have nothing to do with multiple views. If not then you
> probably still have a problem. That would save me and others a whole
> lot of time trying to retest a bug that we've already spend a lot of
> time on.
>
> BTW: Could you guys please update the bug list (the one that is there
> is dated Dec 98) and identify which ones are supposed to be fixed in
> 1.1.1. I'd hate to spend more time identifying bugs that you have
> already fixed.
>
> Thanks
> --jon
>
> Doug Twilleager wrote:
> >
> > We have fixed a few bugs related to state updates for multiple views in 1.1.1.
> > Give that a try when it comes out. If it still happens, please submit a bug
> > to us.
> >
> > Thanks,
> > Doug Twilleager
> > Java 3D Team
> >
> > > X-Accept-Language: en
> > > MIME-Version: 1.0
> > > To: Roger Cottam <[EMAIL PROTECTED]>
> > > CC: [EMAIL PROTECTED]
> > > Subject: Re: [java3d] view to world transform jitters
> > > Content-Transfer-Encoding: 7bit
> > >
> > > What you are describing and the difficulties you are having in pinning
> > > it down sound exactly like what I've encountered. In a previous
> > > posting I reported also seeing jitters when I tried to interactively
> > > scale an object using just a simple TransformGroup -- no fancy view
> > > transforms or eye-to-world mappings. The problem seemed to only occur
> > > for scale factors less than 1.0 and it seemed to affect the whole
> > > transform even though I was only setting scale.
> > >
> > > All the jitter problems I've observed seem to have the same sort of
> > > jittery "quality" which makes me suspect that they are related, but
> > > how? They also manifest themselves in slighty different ways such as
> > > sign flipping, lagging, and just random trashing of the transform.
> > >
> > > Hopefully someone from Sun can shed some light on these mysteries. In
> > > the meantime it's giving me cause for concern because I need all these
> > > features; 1.1.1 is due to come out soon; and I haven't seen the
> > > "jitters" mentioned in the bug list.
> > >
> > > --jon
> > >
> > > Roger Cottam wrote:
> > > >
> > > > Jon,
> > > >
> > > > Yes, I've seen this as well with multiple views. My scenario isn't simple
> > > > so it's hard to nail down exactly what the problem is, but multiple views
> > > > is the key that starts the jitters. I've seen it in TransformGroup objects
> > > > which I am modifying or have modified with a mouse drag...
> > > >
> > > > I also have some issues with code that uses
> > > > Canvas3D.getCenterEyeInImagePlate(), but I can't say that I have a problem
> > > > with that method in particular. It seems that if I use the functions for
> > > > ray casting (generatePickRay and pickQuad) I get a VERY jittery effect on a
> > > > TransformGroup 'above' the ViewPlatform. This happens with only one
> > > > canvas. The idea is that when the mouse is dragged with the right button
> > > > down I project a ray onto a plane perpendicular to the view at the location
> > > > of the 'selected' object. Over two frames this gives me a delta to move
> > > > the viewpoint so I can 'pan' in the view plane relative to an object. I
> > > > print out the 3D points that I calculate on that plane each frame an
> > > > smoothly run the mouse across the window. I get values that jump pos and
> > > > neg and big and small, it may be that the sign is the only thing that gets
> > > > flipped but I haven't studied the data enough to say for sure. I'm not
> > > > sure why yet, but this 'jitter bug' may have something to do with it...
> > > >
> > > > If I find anything I'll let you know.
> > > >
> > > > Roger
> > > >
> > > > At 06:53 PM 3/2/99 -0800, Jon Barrilleaux wrote:
> > > > >I think there is a problem with the J3D computation of the
> > > > >view-to-world transformation. I've seen the problem so far in
> > > > >Canvas3D.getCenterEyeInImagePlate(), View.getUserHeadToVworld(), and
> > > > >and, Node.getLocalToVworld().
> > > > >
> > > > >What is happening is that the value returned seems to "lag" what the
> > > > >ViewPlatform is actually doing, but its not just a simple lag. There
> > > > >seems to be a pronounced "jitter" to it; and if the ViewPlatform stops
> > > > >moving often the lag will remain until the view-to-world transform is
> > > > >read a second time.
> > > > >
> > > > >Although this is only a guess, perhaps this is related to the problem
> > > > >I reported last month (which no one at Sun seemed interested in)
> > > > >concerning jitter which occurs when multiple views are used. That
> > > > >seemed to be view related also.
> > > > >
> > > > >Has anyone seen similar problems with any of the view-to-world
> > > > >transforms? (I know other people have complained about jitter in
> > > > >multiple views.)
> > > > >
> > >
> > > --
> > > ____________________ Peculiar Technologies ____________________
> > > Jon Barrilleaux 3800 Lake Shore Ave. Purveyors of
> > > [EMAIL PROTECTED] Oakland, CA 94610 Alternate Reality
> > > 510.444.4370 voc Augmented Simulation
> > > 510.444.0231 fax www.augsim.com and 3D Solutions
> > > =====================================================================
> > > To subscribe/unsubscribe, send mail to [EMAIL PROTECTED]
> > > Java 3D Home Page: http://java.sun.com/products/java-media/3D/
>
> --
> ____________________ Peculiar Technologies ____________________
> Jon Barrilleaux 3800 Lake Shore Ave. Purveyors of
> [EMAIL PROTECTED] Oakland, CA 94610 Alternate Reality
> 510.444.4370 voc Augmented Simulation
> 510.444.0231 fax www.augsim.com and 3D Solutions
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