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Poor Man's Stereoscopic Projection
Jed Link writes: "This summer I helped built a Geowall
stereoscopic projection (3D) system for the
Southern California Earthquake Center. Although there are no new
concepts involved with this system, what is new is that the system cost a
little over $10K and is comprised of materials that you can buy at any
computer-hardware store. A complete description of the system, as well as
a diary of its assembly is available here. Traditional stereoscopic projection systems like
The Cave which is
used primarily for new product modeling and on a few university campuses cost
anywhere from $150K to $1.5M. They are built into a fixed location, often
requiring significant architectural modifications, so transportability isn't
even an option. The Geowall, on the other hand, can be fixed to a cart
(like we've done) and rolled from room to room. The price-tag makes the
system feasible for undergraduate post-secondary education classrooms and even
high schools. The system is based on a very simple concept, and while its use is currently
primarily educational, I think it's only a matter of time before we see
something like this in the gaming or entertainment industries."
The author is completely off the mark in comparing his "geowall" ($12k, mobile, stock parts) to a cave system ($120k, fixed, custom parts). The projectors are easy for a cave, too. They cost a few thousand dollars, and use the same NVIDIA trick as he does. What is expensive and difficult is the motion/orientation-tracking system. The last cave I was in used a magnetic field to precisely detect the position and orientation of the viewer, thus moving the image ot make it seem like you were crawling around inside the scene. This has to be pretty precise, IIR, or else it feels wrong. And getting a good rectilinear magnetic field the size of a room takes lots of metal -- hundreds of pounds of shielding, permanent magnets, electromagnets, etc -- positioned very carefully all over the room. Not to mention the sensors. This is the part that costs $100k.
I read this Licentiate Thesis work sometime ago, and if you are interested in getting to know virtual reality/environment techniques and CAVE construction it is excellent. It's PDF and over 700K, 146 pages.