Use each trackers of a 
                    Tracking System
                    To visualize tracked points using a tracking device 
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                     as a 
                    Attractor
                    Attract particles to a point in space
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                    . Useful to repulse, attract the particles in function of the position of the actors on a scene.
      
                          Here is a vortex effect arrond 2 trackers
      
