Eyetoy did software motion tracking. It could interpret where your hands, legs and head were from the footage it was taking of you. It was pretty cool but obviously ahead of its time. I don't know if anyone remembers Samba de Amigo for the Dreamcast. It was crazy popular and the first-party maraca controllers for it became really rare and expensive (fetching over $100 each on eBay). Well, you could actually play that on Eyetoy without needing any maracas at all. The camera tracks your hands without your needing to be holding any other peripherals (such as maracas). Of course, if you wanted to hold something in your hand to make like you were actually holding something, you could grab something random, like your TV remote. Another example of an Eyetoy game was this futuristic jet-skateboard game. I demoed it at an EB Games. It could see and interpret your body leans and everything.
