The first table was made from a cardboard box. I lined the inside of a cardboard box with a blue material to assist with the background subtraction. A number of Unibrain Fire-i cameras were zipped tied to the inside corners of the box. This "table" was essentially a prototype to fine out if the crazy god-like interaction idea was going to work or not.
The second table created was a bit more planned. The based was cut out of some MDF and cameras were bolted to the base. Some plastic was used to create a nice circular wall around the edge. Four holes were cut into the plastic to allow the 4 unibrain fire-i cameras to see into the scene. A projector was mounted on the ceiling to project a satellite view of an area of interest onto the table surface.
The working area of the second table was quite limited and the height of the surrounding wall was quite annoying. With this in mind we order some dragonfly cameras from point grey which had a larger field of view. This had the effect of increasing the working area of the table. Redesigning the placement of the cameras and their relationship to the blue wall helped to reduce the height of the blue screen wall. This table was also projector based display.
Projector based displays are annoying for a couple of reasons. They project imagery onto users hands and other physical props that are on the table. They also cast shadows onto the table surface. A rear projected display is therefore a much better option. We purchased a 30" Apple cinema display to replace the projector based approach. A whole was cut into the previous table and the 30" display was mounted.
