• Adobe After Effects Expressions

  Render Order problem between comps

  Posted by Patrick Vaughan on January 28, 2008 at 9:03 pm

  So basic script here driving the front wheel of a bike with the x position property of a precomp. The rotation of the wheel drives many other attributes(pedals, riders movements with an inverse kinematics script, etc.) So I’ve precomped all of those layers into the precomp named “Opponent Biker” which is then animated along X in the comp “speed”. All of this works when scrubbing the X parameter of the “OpponentBiker” precomp…But when keyframing the same x property the animation ceases to work. I assume this is a render order problem

  I assume the answer lies in changing the render order, or perhaps pulling the X position of the precomp from the frame before. I just have no idea how to pull either off with an expression. Any help would be great.

  distance=comp(“Speed”).layer(“OpponentBiker”).position[0];
  circumference=405*Math.PI;
  distance/circumference*360;

  Dan Ebberts replied 18 years, 3 months ago 2 Members · 1 Reply
• 1 Reply

• 

  Dan Ebberts

  January 29, 2008 at 1:29 pm

  I’m not sure about your specific situation, but if you end up with a string of expressions that loops back on itself (this can easily happen with those IK expressions) it won’t work right when you render/preview.

  If you can, try using the Transform Effect instead of animating Position directly.

  dan

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