Re: stereo displays

• To: Curtis Rueden <ctrueden@xxxxxxxx>
• Subject: Re: stereo displays
• From: Don Murray <dmurray@xxxxxxxxxxxxxxxx>
• Date: Thu, 14 Jul 2005 08:02:05 -0600

Hi Curtis-

Curtis Rueden wrote:

Hi everyone,

I put some code into VisBio a while ago to enable stereo displays for Java3D displays. I just copied the logic from TestStereo that gets a GraphicsConfiguration with stereo enabled, if one is available, and uses it when constructing a new DisplayImplJ3D.

Recently a user told me that the stereo looks wrong on his machine, like the image is way too close to the eye or something. I have no stereo setup of my own to debug this, but I did browse around the Java3D FAQ a little and found out that you're supposed to call Canvas3D.setStereoEnable(true) somewhere in order to toggle stereo on (http://java3d.j3d.org/faq/stereo.html). I noticed that nowhere in the VisAD source code is this call made. So, is it actually necessary? Could this be causing a problem like the user described? Anyone have experience enabling stereo for VisAD/Java3D?

The thing we found was that the default eye separation was not
correct.  In the IDV, we set the eye separation as follows:


    protected void setEyePosition(double position) {
        DisplayRendererJ3D rend
            (DisplayRendererJ3D) getDisplay().getDisplayRenderer();
        // From Dan Bramer
        PhysicalBody myBody = rend.getView().getPhysicalBody();
        myBody.setLeftEyePosition(new Point3d(-position, 0.0, 0.0));
        // default is(-0.033, 0.0, 0.0)
        myBody.setRightEyePosition(new Point3d(+position, 0.0, 0.0));
    }

and by default, call it as:

            setEyePosition(0.004);

Ideally, we should have a widget so the user can set it to whatever,
but this seems to work for most cases.  Like you, not having a stereo
display makes it difficult to implement and test such things.

Don
*************************************************************
Don Murray                               UCAR Unidata Program
dmurray@xxxxxxxxxxxxxxxx                        P.O. Box 3000
(303) 497-8628                              Boulder, CO 80307
http://www.unidata.ucar.edu/staff/donm
        "Time makes everyone interesting, even YOU!"
*************************************************************

• References:
  • stereo displays
    • From: Curtis Rueden