Technical part (new)

I plan to use Wii Remote to for this installation.

This is my diagram design for my installation.

The projector is to connect the computer.
The projector will be place at the highest place, to avoid the shadow blocking the screen.
By pointing a wiimote at a projection screen, the spray can can interactive with the projection on the wall.

Replace the ink stick with little light buld

The Wiimote can track sources of infrared (IR) light,so I will try to put the infrared light (IR) inside of the market pen, so the Wii mote can track marker pen that have an IR led inside the can.

This video will show how to create an infrared pen.