• Adobe After Effects Expressions

  data from nested compositions with Expressions

  Posted by Ariel Levental on February 11, 2009 at 10:22 am

  Hi everyone

  I’ve got a 3d comp with a camera and a scene
  it’s a street and I’ve got a poster on one of the walls
  the comp is huge and I’ve scaled it down to fit a PAL size comp
  i want to put a corner pin effect (or 4 expression point controls) on a solid that represents the poster on the wall
  and i need to be able to link that data to a 2d layer outside the 3d scene so i can bake that data into keyframes and export it.

  i know it must have something do to with the fromComp/toComp expression
  but i just can’t seem to figure it out…

  any ideas would be much appreciated

  thanks in advance
  Ariel

  Ariel Levental replied 17 years, 5 months ago 2 Members · 2 Replies
• 2 Replies

• 

  Filip Vandueren

  February 11, 2009 at 1:02 pm

  You’re using the 3D scene as a 2D layer in the Pal comp, right ?

  First off, in the 3D-scene on your 3D-layer “wall” create 4 Point-selectors to locate the 4 corners of the poster.
  Rename the point-controls to “C1” – “C4”

  In your Pal Comp the syntax to get the position of C1 will be:

  
precomp=thisComp.layer("3D scene").source;
wallLayer=precomp.layer("wall");

  // 2D position inside the ful res precomp:
  C1_fulres=wallLayer.toComp(wallLayer.effect("C1")("Point"));

  // 2D position in this comp:
  C1_pal=thisComp.layer("3D scene").toComp(C1_fulres);

  // 2D position on this layer:
fromComp(C1_pal);

• 

  Ariel Levental

  February 15, 2009 at 7:48 pm

  Thanks so much
  I’ll give it a try ASAP

  Ariel

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