About laser scan or position scanning

[claude.rivet]

Hi,

We are intesrested in building a setup where people on stage would affect the projection based on their position. Ideally the system would track the amount of people and their position, being able to track their speed and direction would be quite a sweet extra but not a requirement.

Our first guess was to use two laser scanner limited to 90degree and place them in opposite diagonal corner, so that one person wouldn't be able to obscure another. Somehow I am sure we aren't the first to try something along those lines and I was hoping to get some good pointers from the community; maybe laser scanners aren't the best solution, people must have issues they encountered, code won't be as simple as we think...

what do you guys think?
Where should we look?

Thanks!

[JustynR]

I'm currently working on a project that has the same kind of thing... interactive projection on a floor...

Laser scanners (like the AirScan) aren't really the thing for this, even with 2, more than 1 person on a stage will cause "shadows" in the laser field. If you have 1 person very close to the scanner, not much will be seen behind him/her. Plus, will 1 cause interference with the other? I have used this solution with 1 person on a stage, it works well... but again 1 person...

One solution I'm currently working with is an infared camera and the Point tracker in WD. I'm sure it is pretty straight forward for tracking numbers of people, but it is defiantly more complicated tracking them. This is because simply putting a camera directly above the stage / floor where you are tracking will only track someone if they don't have a hat / helmet / costume on. To solve this, we've had to move the camera on almost a 45 degree angle to the stage.

Another solution I'm dying to try is a product that works with WD. You can see it in the drop down menu for nodes, it's called "Black Trax" and it says (beta) beside it. Just punch that into Google and it'll bring you to Cast's website and you can read about it all there...
Basically you give everyone on stage a belt pack and BlackTrax will tell WD exactly where the person is standing, even the direction they're facing and how high they are off the floor...

I'm sure there's probably a bunch of other ways, but this is what I've been playing with...

Cheers

J

[Christopher Fluegel]

Hi guys,

i think currently both methods are very good for tracking more than one person, the IR camera method and the BlackTrax system. If you follow us on Facebook you can see some projects posted there from time to time using this technology.

For example this one from the LoopLight guys:
http://www.looplight.de/LOOP_LIGHT/loop ... cking.html

Or this demo video using the BlackTrax system directly from the BlackTrax guys:
http://www.youtube.com/watch?v=PI1JXJuRCFw

Hope this helps a little bit