The above link is to an interesting article on howstuffworks.com and it examines the reacTable. A digital table built solely for the purpose of using the reactivision software. This is definitely something to look into using. They are expensive to buy so i think the most logical solution to this is to make our own using this as a blueprint. A particularly interesting part of this article is
“Both the camera and projector point up toward the bottom of the tabletop, but they each serve a different purpose. The camera, which runs on a special vision engine called reacTIVision, looks up at the blocks and analyzes several factors:
- Which sides of the blocks are facing down on the table
- Where the blocks are in relation to the table’s center
- Where the blocks are in relation to other blocks
- How the blocks are positioned around their own axis
- Any other tangible adjustments made on the table’s surface that might alter pitch, filters and so forth”
This is more or less exactly what we want to create even with less features. This table reads what size of block and what angle they are at. we more or less just need to detect what block is on screen that will be translated to whatever symbol we want it to draw.