• Adobe After Effects Expressions

  Layer Space Transforms – precomps

  Posted by Nathan Clark on December 23, 2009 at 10:36 am

  My brain is hurting. Please don’t laugh at how simple this might be (I assume it is going to be)

  • I have a PreComp with 2 Nulls positioned in 3D space

  • In the MainComp the PreComp is a 3D layer and I have enabled collapse Transform.

  • I need to get the 2D position of the Nulls (within my precomp) in my MainComp for use with the Beam Effect.

  Any Assistance would be amazingly helpful!

  Many Thanks,

  Nathan

  On Point Cloud Nine

  Nathan Clark replied 16 years, 4 months ago 2 Members · 2 Replies
• 2 Replies

• 

  Andy George

  December 23, 2009 at 6:02 pm

  Nathan,

  It’s possible to link attributes from one composition to another.

  The easiest way would be to:

  Open both compositions at the same time, so that you can see all of the attributes you want to link on your screen.

  Then you can quickwhip the start and end points in the beam effect in your main comp directly to the position property of your nulls in the precomp.

  It should look something like this

  comp("Comp 1").layer("Null 2").transform.position

  -Andy
• 

  Nathan Clark

  December 23, 2009 at 10:41 pm

  Hey Andy,

  Thanks for the reply, but this is not exactly what I need.
  I know I can easily use values from any Comp by pick whipping,
  What I need is for the MainComp to know where the 3d nulls (within the PreComp) are positioned relative to the camera (within the MainComp) and then determine their 2D positions using layer space transforms (All from within the MainComp)
  Does that make sense?

  Thanks

  -Nathan

  On Point Cloud Nine

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