Mixed Reality Tabletop
by Jonathan Deutsch
Andrew Wooster, Minister of Search:
The projection map table was basically a large touch screen table which allowed people to manipulate a globe-like map by touch, zooming in and out and overlaying different satellite and topographical data sets.
It seems that Northrup Grumman put together an interactive tabletop for military cartography and simulations. There’s a pretty cool demo video on their site.
This reminded me of my research at Purdue: the Mixed Reality Tabletop (MRT for short). The main difference between the two setups is that the Northrup Grumman table uses touch sensitivy on the table itself, wheras we opted to used a camera mounted overhead and analyzed the video to detect actions. This meant we had to worry about lighting conditions, shadows, and camera calibrarion. Our system was really designed to be a collaborative medium where two people could share the same tabletop, so the camera was a natural choice to use for such purposes. I think the videos on our site show that the image detection method can work well and allow users to perform advanced operations such as drag-and-drop of virtual objects (due to Dan Belkins’ great work). Of course, the other real advantages of MRT is that it costs 100 times less than the Northrup Grumman system, and you can play games such as Networked Tic-Tac-Toe and Pong on ours (my work!).
How much would an MRT cost? Whats the hardware required? Set up time? etc…
I think that this is absolutely brilliant and has limitless possibilities. I would love to hear more.
Thanks,
Roger
Our goal for the MRT was to cost about $5000. IIRC, $2000 for the PC, $2000 for the projector, about $600 for the camera, and $400 for the table and mount. It really just required pretty vanilla hardware — we used a Dell PC, a DLP projector, and a firewire camera. The table/mount could probably be setup in about a day. A fast internet connection is also required for doing the mentor/mentee setup.
The reason for the expensive projector was that it has to be able to be triggered to turn on and off really quick (and not have any “glow”, thus DLP was used). This is because if the camera were to pick up the projected image, it would result in an “infinte mirror” effect. So basically the MRT works by projecting an image, then capturing one, then projecting, etc. It took a lot of effort to get the synchonization between the two just right.
One thing to remember though is that this was a research project, so there were no plans to mass-produce this or anything.
Wow! Thats a pretty penomenal price!
For the cost of a plasma screen you can change the desk into a touch interface screen. Combine this with an LCD monitor or three and you have a pretty slick setup.
I would think that there is quite a demand for something like this. Replace cadavers with sections of a body for auditorium inspection, much like the motherboard example from the vid. Discuss a design layout and allow for immediate highligting and alterations with a group interaction.
How much do you estimate that the Grumman system goes for?
One of our main applications for the system was actually for high school dissections, so that a medical center could perform it, but students could watch and interact.
I believe I heard the Grumman system goes for $100,000+, but that could be incorrect.