1 Reply Latest reply on Sep 7, 2015 8:56 PM by Rick Gerard

    How do I apply tracking to multiple paint strokes?


      After Effects 2015 CC...


      This should be easy.  I'm stumped.


      I have video footage.  In the background are multiple street lights against a dark sky.  I need to motion track, clone out the street lights and be done with this scene.


      Tracking, not a problem,

      Cloning out the street lights, not a problem...


      Adding the tracking to multiple street lights... I cannot figure it out.


      I have- lets say- 14 street lights.  Can I apply the 1 motion tracking data to all of them?  Seems like when I try to apply the motion tracking data to all of the clone paths, they jump in origin to the same spot, which is the origin of the motion tracking.  I want the 14 clone paths to keep their original but move with the 1 motion tracking.  I don't want to have to set up a motion tracking for each street light and then apply each of the motion track's data to the individual path.  Does that make sense?



        • 1. Re: How do I apply tracking to multiple paint strokes?
          Rick Gerard Adobe Community Professional & MVP

          If you have 14 streetlights then you need 14 trackers. The only way around that would be if all of the Street lights were on the same plane and the plane was perfectly lined up with the camera.  Otherwise, parallax will give each streetlight they slightly different movement.


          There is an outside chance that you could stabilize, not warp stabilize, the shot and keep all of the streetlights locked in position. You could then clone all 14 street lights then put the motion back in the shot.  You would do that with a pre-comp.


          The only other option I can think of would work if there was no parallax change between the streetlights. You could track the most prominent light, then apply that tracking data to a null, then use a value + expression to attach a null to each of the other streetlights. If the nulls follow then you could use and expression to tie each null to a clone. You would also have to attach the clone source to a null using an expression that uses toComp space. For example if your track was applied to Null 1 and the and you wanted to use Null 2 as the clone source your would apply this expression to Clone Source Position

          L = thisComp.layer("Null 2");

          L.toComp([0, 0])

          The most efficient approach depends entirely on the shot. If it's a shot panning down a street then you'll probably need 14 trackers and 28 nulls.