Multitouch Biggie (MTbiggie) – How To

What’s a Multitouch Biggie (MTbiggie)?

A Multitouch Biggie, MTbiggie for short, is a low-cost multitouch table. It can be used for a variety of purposes including: drawing, OS navigation, games, entertainment and more.

I created the Multitouch Biggie to show people how something that seems complicated or ‘magical’ can be made simply and at low cost.

The MTbiggie uses the “Front Diffused Illumination” multitouch technique, with ambient infrared light and a DIY infrared webcam. The MTbiggie is similar to the MTmini, but includes a projected image and infrared webcam (rather than a normal webcam).

The MTbiggie isn’t the most stable and robust setup, but it is the easiest to build. To see other methods of building more stable multitouch displays, view the full multitouch display list.

Parts List

• 2 chairs (or anything to prop up the acrylic)
• Piece of clear, flat sturdy material (ie. glass, acrylic, plexiglas)
• Projection material (ie. printer paper, tracing paper, rosco projection material, etc)
• Infrared webcam/camera (learn to build one yourself here)
• Computer (dual core recommended, but not required)
• Projector
• Mirror

Total Cost: $400 (using low end projector) – $1000+ (using high end projector) – not counting the computer

How’s it Work and What Conditions are Necessary?

When you place your fingers on the surface, shadows are created where your fingers are placed. The webcam sees these shadows and sends the image to the tracking software which tracks the shadows as they move on the touch surface (paper). Below is a video demonstrating the view of what the camera is seeing and tracking.

All you need is a room with (at least) some infrared light (most lights give off infrared light); a dark room will not work. Even room lighting gives the best results. Lights shinning from multiple directions onto the table gives better results than lights from one direction.

Software and Demo Downloads

• Main Finger Tracking Application – needed to track fingers on the MTbiggie
  • Community Core Vision (CCV) – Windows, Mac, Linux tracking application.
• Mouse Driver – for controlling your mouse cursor
  • Windows Mouse Driver
  • Windows 7 multitouch driver (Multitouch Vista)
  • Mac, Linux, Windows Mouse Driver from TUIO.org
• Demos and Applications – Various applications that can be used with the MTmini
  • Demo pack applications (fire, physics, ripples, multikey, and more) - via ccv.nuigroup.com downloads page
  • My Demo Applications
  • Angry Birds (seen in the video) uses one of the mouse drivers above

Tracking Software Installation and Setup Guide

• http://sethsandler.com/multitouch/community-core-vision-guide/

My Results and other Techniques

You can find information on how to make your own multitouch surface (like the one I built in the video below), by viewing the How to Make a Multitouch Surface page.

Need Help?

If you need more help than is provided here, please go to http://nuigroup.com/forums where there are hundreds of other people that are building multitouch devices and can answer your questions quickly.

Other Resources

• How to Make a Multitouch Surface
• Multitouch Book (free PDF)
• Multitouch Terminology
• My Personal Multitouch Surface Build
• NUIGroup (the best place for immediate help on hardware and software)

Thanks to:

• NUIgroup Community
• Cyrus Ortiz-Luis