• Adobe After Effects

  Preserving ‘orient to camera’ within a precomp?

  Posted by Nico Jones on June 7, 2010 at 4:44 pm

  Hi guys,

  Is there any way to preserve the ‘orient to camera’ effect within a precomp?

  I have composition A, which is a fairly complex arrangement of block colour solids, some of which are circles. I want to auto-orient these circles to the camera to make it seem like they’re 3D spheres.

  It works fine, but obviously when I precompose comp A into comp B, I lose the auto orient effect when I collapse the transformations. I need to be able to control the object in 3D in comp B.

  Is there any way around this? Any way to force objects in comp A to orient to the camera in comp B?

  Many thanks,

  Nico

  Nico Jones replied 15 years, 11 months ago 2 Members · 2 Replies
• 2 Replies

• 

  Andy George

  June 7, 2010 at 6:00 pm

  Hi Nico,

  I can think of a few ways to tackle the problem but not without diving into some expressions.

  You could place an identical camera in your precomp and then link it to your main camera via quick-whipping the position/orientation properties from one comp to another.
  That way the camera in your precomp will mirror your main comp.

  This method starts to run into problems if you parent your camera to null objects to animate the camera.

  A more robust method might be to use an orientation expression linked to a null object. Then use this null object to drive your camera and the orientation of the layers in the precomp.

  Turn auto orient off.
  Put a 3D null object in the same position
  as your camera. Parent the camera to the null.
  In your precomp you will want to apply this expression to the orientation
  of the objects you want to follow your null
  
L = thisComp.layer("Null 1");
lookAt(fromWorld(L.toWorld(L.transform.anchorPoint)),transform.anchorPoint)

  With the top line of the expression selected after the = sign, quickwhip to the orientation property
  of the null in your main comp. Now it should look something a bit more like this
  
L = comp("Comp 1").layer("Null 1")
lookAt(fromWorld(L.toWorld(L.transform.anchorPoint)),transform.anchorPoint)

  Now as you animate the null object the camera will match it’s position and the layers in the
  precomp will orient towards the null objects anchor piont.

  -Andy
• 

  Nico Jones

  June 8, 2010 at 8:12 am

  Thanks for the help Andy! I’ll definitely look into that…

  Nico J BB

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