There’s So Much Stuff…

The trouble with trying to make a multi-touch application is that there are so many different things to consider. Hardware wise there are many ways to create a touch screen including LLC, FTIR and DI. These use various aspects of reflection and camera tracking to find out where the surface has been touched. Details of the various techniques can be found here [http://nuigroup.com/forums/viewthread/1982/]

The large scale demonstration will consist of a large perspex sheet, a diffuser (such as tracing paper), a projector, a camera with an IR filter and two IR lights. All the equipment will be behind the screen and the IR lights shine onto the screen as well as the projector. The diffuser allows the IR light to diffuse through it and when a person touches the surface, the camera tracks the reflection of IR light and passes that through various filters to allow for a clear blob which is then given an ID and passed into a third party application. The tracking software used is here [http://tbeta.nuigroup.com/]

There are a few software options for building a multi-touch application and a variety of languages to program in (C++, Java, Processing) but the concentration is on finding a framework that will make things easier. Sparsh UI is supposedly good although this has yet to work. There is a plugin for TouchLib (but TBeta is better and is what is being used for tracking) which sends TUIO data (the same as TBeta) but there is a problem preventing connection of the two at the moment. VVVV is a multipurpose tooklit that is similar in style to MaxMSP but there are some connection issues there too.

Flash seems to be the best option as it has been connected but there is so much involved in all the tutorial files that there has been some failure in writing the code from scratch.

The decision has been made to start working on the application within flash but without the inputs from the MT. This means that work can still progress as well as research into how to sync the information being transmitted properly.

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