• Adobe After Effects Expressions

  Changing Values in a Precomp

  Posted by Jaime Matthew on September 23, 2020 at 11:26 pm

  I’m trying to do something that seems relatively simple, but it’s beyond my skills with expressions.

  I have a layer in a pre-comp that I want to be able to scale (and set keyframes) from the master comp so that I can set the timing in the main comp (and possibly impact multiple precomps at the same time).

  I won’t know the durations of the shots ahead of time, so being able to put the keyframes in the parent shot will save me a world of grief in these templates.

  Andrei Popa replied 5 years, 11 months ago 2 Members · 1 Reply
• 1 Reply

• 

  Andrei Popa

  September 24, 2020 at 6:00 am

  This was my setup. If you change anything(comp name, precomp name, effect name) you must also change it in the expression.

  Main composition name = Main Comp

  Pre-comp name(as layer, this means as seen in timeline, not project panel) = Shot 1

  Add a 3D point effect to pre-comp.

  I named it CTRL.

  Now go inside the precomp and on the layer that you want the scale to be modified write this expression:

  myComp = comp("Main Comp");
  myLayer = myComp.layer("Shot 1");
  myEffect = myLayer.effect("CTRL")("ADBE Point3D Control-0001");
  myEffect.valueAtTime(sourceTime(time)+myLayer.inPoint);

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