MultiTouch! It’s here, it’s big, and it’s bold!

This session had so much information flying at me, I didn’t really have time to break this out from a stream of conscious.

History Briefing of MuliTouch technology

Started mostly in the early 80’s, but really got popular in 2006 at Jeff Han’s TED speech.
Seen more in Hollywood than anything else.

How to get started?

Consider hardware, how the user will feel when using it.

DIY Vision Based Systems

Popular types of Vision Based Systems:

  • Frustrated Total Internal reflection (FTIR)
  • Diffused Illumination (DI)
  • Diffused Surace Illumination (DSI)
  • Laser Light Plane (LLP)

Standard Process:
Camera -> CCV (interprets blobs -> TCP Socket -> Flash

Biggest advantage for DIY — Form factors, large scales, multiple inputs, etc.


Advantages: Very sensitive, easy and cheap to build, unlimited sizes and form factors.
Disadvantages: Compliant layer required, projection “hot spots”, Top layer can be damaged due to unprotected.


MS Surface originated on this style.
Advantages: No compliant layer


Replaces DI
Uses Endlighten Acrylic

Advantages: Glass top, few layers to build, less reactive to outside light
Disadvantages: Acrylic is soft, more costly.


Advantages: Works on LARGE implementations easiest.
Disadvantages: Lasers are hard to calibrate, dangerous to work with.

Some parts ideas:

Ribbon based IR LEDs: Env Lights –
Visual Light Filter: Ebay Seller – omegabob
Acrylite Endlighten – Contact local glass/acrylic fabrication. Polish the edges to transfer light.
Projection Surface – Rosco, typical/standard type.
Help/Software –

Design Considerations:

Sizing, so that multiple people can interact at the same time.
Angles are important as well.
Standard components aren’t feasible.
Physics are very important. (Really?)

TUIO – Tangible User Interface Object

  • Messaging format describing blobs
  • UDP/TCP -> Flash Player
  • Pros: Platform independent
  • Cons: Non-native to Flash/Flex

They also showed a cool simple demo for keeping track of multi-touch by extending a single-user (via mouse) drawing component.

Flash’s Future in MultiTouch:

  • Compatible with all OS’s that support multi touch (Win7, Mac, mobile platforms).
  • Native support in Flash!!!! No more relying on TUIO or 3rd party translations.