I will make game in 2-3 days..real game..

dude, thats one neat lookin and very promising idea. can't wait to get my hands on a demo

too bad there isnt a good way to accurately calculate depth of a joint, you could make a hell of a sword fighting game :P

hey lostclimate, that is an awsome idea
Two or three leds on some kind of a sword and it should already work pretty nice with my point detection the alternative would be using the wiimotes accelerators :P or probably a combination of both.

Instead of leds you can use some unique colors for the markers. After all its a 2d image from which you are trying to get information. Same thing has been used by camtrax people. You can extract x,y position and angle also if you use the marker with one side longer. The z depth can be calculated by calculating the size of marker on screen.
Camtrax has also a dll for use with your application.

Man i know all that..point is to make games that you can play only with webcam..

So can you share your approach. It would be good to know how you motion capture in your demo.

System code is secret.
But you can ask "Sony"..

Google is your friend.

There are a lot of papers on this out there. There are several techniques you can use for this.

I have been looking at many such papers. And I have some of my own ideas too. Got some Flash code to look at too. And got the dll from slin and would see what I can do. Secret - LOL.