Forums > MaxMSP

jit.openni maximum user trackable … HELP!

Jul 21 2013 | 4:59 am

Hi! After searching a lot in the forum here, I found out that the jit.openni have a maximum of 15 user trackable. I was wondering if there is any way to limit the user tracking to 2 user for example… so that if a 3rd one enters can not be tracked at all.

Thanks in advance

Jul 23 2013 | 5:08 am

The meta problem you are writing about is…How given many people in the Kinect’s view can I select only 2 users?

Much of that is your choice based on the desired design/look/functionality of your patch.
Is it the 2 closest users?
Is it the 2 users jumping up and down?
Is it the 2 users waving their hands?
What happens if a 3rd person walks in front of person #2? Do we ignore that new person?
…and so on…

NITE, the technology that does the user/skeleton tracking has its own internal algorithm to detect and track the skeletons. There was never a working method to define for NITE what skeletons to track. So…NITE tracks anything it can see and your CPU can process. There was never a published API to determine the max number of users that NITE could track. So I coded jit.openni to support up to 15 (I never had more than 3 reliably tracked).

Therefore, it comes to your code to decide/choose which users to track. You will need to think through questions like I wrote above. After thinking on these, then you can write your patcher with that logic and use the userid values to filter joint/position data. It is possible that NITE may be tracking users that you never use in your patch.

Jul 25 2013 | 3:30 am

Thanks a lot for this answer. I was wondering if was possible to say to the jit.openni just track 2 (as you coded it for track 15). When this is not possible then of course I will do it in the patch with logical things :)
Thanks again a lot!

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Forums > MaxMSP