Spatial Practice - Research: Front Diffused Illumination

The simplest option appears to be FDI, as it does not require an IR light.


Front Diffused Illumination:
In Front DI, infrared light is shined at the screen from above the touch surface. A diffuser is placed on top (preferred) or on bottom of the touch surface.  When a finger or object touches the surface, a shadow is created under the object and seen by an infrared camera below the surface. This method is what the MTmini uses, but without the need for infrared light (since there is no visual display to remove). The MTbiggie also uses this technique. An image is displayed by using a projector connected to a computer pointed towards the projection material.

from: http://sethsandler.com/multitouch/frontdi/


The model I will be attempting is known as the "MTBiggie" which is a larger (biggie) size multitouch (MT) surface that allows visual feedback via projection.

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
• Computer (dual core recommended, but not required)
• Projector
• Mirror