5 Replies Latest reply on Oct 21, 2014 1:11 PM by ImagineerSystems

    pencil through hand

    Don Productor

      hello, I'm trying to perform a pencil through hand effect in AE:

      • I close up the hand with a camera fixed on a tripod.  Fingers still extended all time, whole hand make some light movements since wrist over a still background.
      • I want to add a 3D generated pencil (Cinema 4D or else).   It must show that pencil pass through hand.


      I tried (by the first time) Mocha AE for hand tracking.  I tracked the hand movements then I copied keyframes to AE.  Then I noted than only X and Y movements are copied, all Z axe is = 0.


      I think to apply Camera Tracker to the hand.  But take in account only hand is moving, but background stills.   Maybe this could work if first I apply a mask to the hand, I'm not sure.


      I'm not sure what should be the best technique for this effect.  Maybe I'am misunderstanding how Mocha works.


      Some suggestion to me ?

        • 1. Re: pencil through hand
          Dave LaRonde Level 6

          This is a legit suggestion -- try a magic book.  OR re-shoot the hand on a green screen.

          • 2. Re: pencil through hand
            Don Productor Level 1

            thank you Dave, this particular effect could be done with some makeup.  But this is a practice only, I'm just learning about Mocha.

            • 3. Re: pencil through hand
              Rick Gerard Adobe Community Professional & MVP

              Tell us more about what you want the shot to look like. If the camera and the hand are at a similar angle then two tracking points are all you need. If the hand rotates then you need a tracker that will track 3D motion and AE does not have one. Syntheyes would do that. Mocha will not do that either. If it were me I'd shoot a shot as a clean plate -- no hand, then from the same camera position, shoot a shot with the hand in the shot, then from the same camera position, shoot a pencil moving into the frame and through the space where the hand used to be. If the camera was locked off then I'd just do a little simple masking to make the pencil look like it passes through the hand. If the camera is hand held then I would stabilize (remove all motion from the shots, then do the masking to make the pencil look like it is going through the hand, then put the camera motion from the shot with the hand back into the scene.

              • 4. Re: pencil through hand
                Don Productor Level 1

                then Rick what you mean is there is nothing I can do in order to actívate Z axe when I copy keyframes to AE ?

                • 5. Re: pencil through hand
                  ImagineerSystems Level 1

                  The bundled mocha AE CC exports 2D tracking data (either X,Y, scale, rotation) or corner pin. If you require 3D tracking AE has the 3D Camera Tracker or you could upgrade to mocha Plus or mocha Pro which both have a 3D camera solver. Here you can find some video tutorials about mocha's 3D camera solve:


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