This article will provide an overview of the creation of the monolith multi touch computing interface – a multi touch solution based on:
· The Microsoft Surface™ table design and touch tracking concepts
· Jeff Hans frustrated total internal refraction methods of finger tracking
· Open source visual light / infra red light, finger tracking solutions:
- Touch lib
- T-beta/CCV
The purpose of the monolith design is to create a touch screen solution to host complex multi touch based applications, such as picture and video manipulation and information based applications designed to deliver information to the user which can be manipulated and organised with tactile manipulation. Although this is the primary intention for this design, the monolith in effect is a surface based multi-touch computer capable of many other applications with its extension at this stage limited only by developer imagination.
The second section of the paper explores the technical and some design aspects of creating multi touch applications for use on multi touch surface computers. The programming language, which will be used in this exploration, is adobe action script 3 that is used by the flash engine. The method of exploration will be in the form of creating a series of programs for use on the surface and a discussion of the pro’s, con’s and design limitations of this language for the said platform.
Overview
The multi touch table uses a very simple method for tracking the finger/object touches/movement on the surface of the screen. It takes advantage of a cameras ability to see a greater spectrum of light than the human eye, extending into the infra red spectrum. The monolith rear projects a screen onto the surface of the table for the user to interact with, at the same time an infra red array of light is projected or refracted onto/into the same surface. A camera can then record where the finger has touched the screen by filtering out the visual light of the projector with an IR pass filter and by tracking just the infra red reflections/refractions. The main key to this IR recording system is the separation of the IR light from light visible to the human eye, making it easy to separate the two for tracking and surface projection.
One of the most exciting elements of exploration for computing in the near future is human gesturing which can be split into two categories for surface computers:-
“Surface Touch gestures” where the user makes a gesture on the screen to tell the computer to do something to the interface; this could be as simple as pulling two fingers apart to zoom in, or a series of more complex gestures.
“Non surface gestures” where a user makes a gesture above (not touching) the screen to tell the computer to do something; this again could be a simple gesture like waving objects away for instance.