Track object position


I want to make an installation which needs to track an object’s position.

The viewer will stand in front of a wall on which a video is being projected. The viewer will hold a kind of wand and move it to interact with the video.

Much like Wii. I am considering using a webcam and place a led on the wand’s tip. Does this make sense? Should it be a normal webcam with a colored led or should I use and IR webcam with an IR led? Or is there a better way?

Thanks in advance,

webcams are slow so better use an analog security cam or uncompressed firewire
IR leds work ok with black and white cams only and you need an IR pass filter in front of your cams optics, this can be the inside of a floppy disk which is for free but crap, or you can buy a hoya R72 or SCHOTT RG 850 they cost about 40 euro.try to match the leds spectral peak to the filter you use (R72 is 720nm RG850 is 850nm).
plug it into a contours freeframe node play with tresh and you got yourself a position
have a good tracking!

hi viktor,


One question: how can I connect the analog security cam to my laptop? Do I need one of those expensive video capture cards? What kind of connections do these cams provide?


well i dont have any experience with usb capture boxes, but maybe some other ppl here…


if we are talking about only one analog camera and a desktop PC you can use a very basic and cheap PCI capture card.
I made really good experiences using the Leadtek WinFast VC100 XP that you can find on the web for apprx. euro 13,00-15,00.
Please do not use the driver that is coming with the card but


Dude i did it with my jvc mini-dv by firewire, i attach my patch, with it you only need a common flashlight and move it in front of camera to draw in the screen.

lineaporcamara.v4p (109.0 kB)

Thank you all for your replies. Thank you vladimir for posting your patch. I will investigate all this.