For another example of a multi-touch technology (one not based on total internal reflection, however), see http://wall.accenture.com/ . We've been working with multi-touch screens 10-12 feet wide for a couple years now.
One of the challenges with multi-touch technology is the question of where to put the cameras (or other detectors). If the cameras are in-plane -- if they look directly across the field of interaction -- then there are ambiguity problems as you try to interpret multiple occlusions (fingers) as definite x,y points.
If the cameras are behind the screen plane (as seems to be the case with the NYU work, and also with Microsoft's multi-touch system exhibited at SIGGRAPH last year), then ambiguity is easier to deal with, but you can *only* work with projected or freestanding screens. This is a serious limitation in practical applications. Most of the durable, day-to-day screen technologies are enclosed in some way.
Slashdot Mirror
For another example of a multi-touch technology (one not based on total internal reflection, however), see http://wall.accenture.com/ . We've been working with multi-touch screens 10-12 feet wide for a couple years now.
One of the challenges with multi-touch technology is the question of where to put the cameras (or other detectors). If the cameras are in-plane -- if they look directly across the field of interaction -- then there are ambiguity problems as you try to interpret multiple occlusions (fingers) as definite x,y points.
If the cameras are behind the screen plane (as seems to be the case with the NYU work, and also with Microsoft's multi-touch system exhibited at SIGGRAPH last year), then ambiguity is easier to deal with, but you can *only* work with projected or freestanding screens. This is a serious limitation in practical applications. Most of the durable, day-to-day screen technologies are enclosed in some way.