• Adobe After Effects Expressions

  arrows, tracking, and pinning, i’m stumped

  Posted by Robert Paynter on January 16, 2008 at 7:09 pm

  What I’m trying to do is track two points of a human in motion.
  Lets, say for example, the hand and the foot. Then create a string between to two. Easy enough with corner pin, stroke, etc., Heres the challenge I would like to add arrows on either end that would follow the angle the line is creating.

  got that ?

  anyone have any advice, answers?

  Dan Ebberts replied 18 years, 4 months ago 2 Members · 1 Reply
• 1 Reply

• 

  Dan Ebberts

  January 16, 2008 at 8:19 pm

  The rotation expression for your arrow is going to look something like this (not tested):

  trackPt1 = ; // pick whip this
  trackPt2 = ; // pick whip this
  adjust = 0;
  delta = (trackPt1 – trackPt2);
  radiansToDegrees(Math.atan2(delta[1],delta[0])) + adjust

  Depending on how you have your arrow set up, you might have to change “adjust” to 90, -90, or 180

  Dan

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