[PD] PD and GEM for virtual environments

[Peter Brinkmann]

Hi,
I've been thinking about using PD and GEM in CAVE-like immersive virtual
environments like the PORTAL at TU Berlin and the CAVE/CUBE at UIUC
(www.math.tu-berlin.de/geometrie/f5/portal.shtml, www.isl.uiuc.edu).
Has this been done before? I did find a few passing references to
PD and sound in CAVEs on the web, but nothing about PD and GEM.

The basic setup of a CAVE consists of a number of projection screens,
aka walls (three for the PORTAL, six for the CUBE), controlled by one
computer each, plus one master computer. Here's what I have in mind:
    - The master does audio with PD and handles user input via mouse,
    keyboard, MIDI controller, etc.
    - The wall computers run visualizations with PD and GEM. Those
    visualizations are identical except they use different viewports
    for different walls.
    - The master controls the walls via netsend/netreceive.
    - A python script on the master handles CAVE-specific input (such
    as head tracking data) and updates the master via pdsend/pdreceive.
    It may be a good idea to build a little python extension that
    encapsulates the functionality of pdsend/pdreceive.

All this seems straightforward enough, but there are two issues I'm
worried about:
    - Can I change the viewport in GEM? The FAQ has some comment regarding
    the default viewport, but little information on how to change it.
    - How well does GEM support stereo viewing?

Any thoughts would be appreciated!
Best,
    Peter