• Adobe After Effects Expressions

  Linking motion tracking data with clone

  Posted by Lindsay Horner on April 12, 2007 at 10:40 am

  Hi

  Sorry if this is a rather basic question, I’m rather new to expressions.
  I’m linking some motion tracking data to a clone brush to roto out a tracking dot and am having some trouble. Linking the position of the clone brush to the tracking data is no problem, but I’m not suite sure how to make the clone source position property work. I have this:

  motionTracker(“Tracker 2”)(“Track Point 1”).attachPoint

  …to link the attach point of the track to the position to clone from but I can’t work out how to shift this point (for example) 10px to the left in order to make the clone work. I know this should be simple!

  Thanks in advance
  Lindsay

  Lindsay Horner replied 19 years, 1 month ago 2 Members · 2 Replies
• 2 Replies

• 

  Filip Vandueren

  April 12, 2007 at 10:59 am

  you could use a fixed value like this:

  motionTracker(“Tracker 2”)(“Track Point 1”).attachPoint+[10,0];

  Or I would suggest you disable the expression, set the value of the ‘Clone From Position’ to 10,0, and then use this expression:

  motionTracker(“Tracker 2”)(“Track Point 1”).attachPoint+value;

  that way it’s easier to tweak by scrubbing in the value in the timeline, without changing the code, and you can even keyframe the relative position.
• 

  Lindsay Horner

  April 12, 2007 at 11:06 am

  Awesome, thats even easier than I thought.

  Thanks for the quick reply! Good forum this one.

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