Identity of multiple leds
 

Two questions.

I want to track two leds, one on the head and the other somewhere else. How can I guarantee that the one on the head is always assigned the same identity each time I run the experiment? Will this occur if the two leds are always in the same location when I activate PPT?

With a 4-camera PPT, if one of the leds goes out of the field of view of two cameras, will it still be tracked?

Q#1: Absolute marker identification
There is no way to initialize your marker identification purely within PPT or combined with Vizard without imposing some external knowledge. For your application, writing a reset function that finds the LED marker with the highest altitude (the head) and assigns it to a head position handle (e.g., posHead), and assigns the other to the hand position handle (e.g., posHand) is really the only way. In this case, you would have to disable automatic position head tracking and do manual head position tracking.

Q#2: Can an IR-LED be tracked by just 2 of 4 cameras
Absolutely.