frustrated total internal reflection

Even before finishing my own infrared led touch screen, but after trying other screens and tables built with the same kind of technology, Luis came up with very valuable information: 4 Infrared lasers provided with special line generators, and placed in the corners of the screen can substitute the endless rows of leds and the soldering that they implied.
Again, a very generous group of people related to NUI group have posted the info on how to implement this formula online: http://labs.ideo.com/2009/02/11/hacked-rear-projection-tv-into-multitouc...

For this part I will do some research in using Touchlib http://nuigroup.com/touchlib/
"Touchlib is a library for creating multi-touch interaction surfaces. It handles tracking blobs of infrared light, and sends your programs these multi-touch events, such as 'finger down', 'finger moved', and 'finger released'. It includes a configuration app and a few demos, and will interface with most types of webcams and video capture devices."

Because I'm not a programmer / engineer myself, I will have to use TUIO protocol and something more manageable such as Flash, VVVV, Processing, PureData, or something of that sort. My friend Luis Fernández is coaching me through email, for which I'm quite grateful.

Regarging the touchscreen itself, it is still not 100%finished because I don't have a special kind of silicon which is needed in order to avoid air bubbles preventing the contact of the fingers with the acrylic plate and the projecting surface. I'm looking for ways to solve that issue. However it seems that there is a TUIO simulator, which allows writing applications and testing them without having to use any kind of multitouch interface, so it won't be necessary for me to have the projector, and all the screen paraphernalia on all the time while experimenting.
The most common simulator is the one made by the team who designed the reacTable at my former university in Barcelona: http://mtg.upf.es/reactable/?pic=reactivision04.png

With this, and the right libs and plug ins, I will be able to start testing my experiments quite soon.

After the experience with "Frontera" which worked with a kind of gesture tracking that is more similar to the single touch interaction, I'm experimenting with other forms of multitouch screen interaction. The first one I'm looking into is FTIR, which is becoming very widely used. Great tutorials about how to make your own multitouch screen can be found online. I'm using one that I found while surfing this site:
http://www.nuigroup.com

By Lilia Perez
After the experience with "Frontera" in which I used 2 firewire webcams and an Open Source application created by Arjan Scherpenisse and Robin Gareus to achieve the one touch motion tracking, I'm experimenting with other forms of multitouch screen interaction. The first one I'm looking into is FTIR, which is becoming very widely used. Great tutorials about how to make your own multitouch screen can be found online. I'm using one that I found while surfing this site:
http://www.nuigroup.com
I will soon post a direct link, but I don't have it right now.