• Adobe After Effects

  Grid of single object, but want each to have different randomized rotation

  Posted by Jason Parekh on October 18, 2011 at 3:23 am

  Hey all,

  I’m curious how you guys would solve this. I have a grid of the same object, let’s say 4 columns and 2 rows. I have a reusable composition that contains a single object, and then a larger composition that has this reusable composition repeated 8 times.

  In the reusable composition I’ve set an expression for the rotation I want. The problem is, I don’t know how I can randomize this rotation (at minimum, the start time) across all eight instances that appear in the final larger composition.

  I’m aware I could paste my expression eight times in the larger composition, but I was wondering if there’s a way I could achieve this without resorting to that. Ideally, inside the reusable composition’s expression, I could have a variable that’s a unique ID for that instance. Is there anything like this? Any other thoughts on the general problem?

  Thanks,
  jason

  Walter Soyka replied 14 years, 11 months ago 4 Members · 3 Replies
• 3 Replies

• 

  Angelo Lorenzo

  October 18, 2011 at 3:38 am

  As far as I know, I think transformations acting on an object need to be applied to that object. In other words, if I want to spin object A, I have to apply the expression to object A, but I can use properties of objects B,C,and D to help influence A.

  You may also want to run a different random seed expression on each object.

  I don’t use expressions a ton, but I haven’t come across a more global way of applying expressions. Maybe someone can crack it open for both of us.

  – Angelo Lorenzo
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• 

  Tudor “ted” jelescu

  October 18, 2011 at 6:48 am

  I would use ShapeShifter AE from Mettle or FreeForm Pro. They both have Generator- it creates instances of the object that can be positioned and animated (roataion in your case) using a random seed. You can use it in 2d but the plugins will allow you to manipulate in 3d, so depending on what you want to do this may be interesting for you.

  Tudor “Ted” Jelescu
  Senior VFX Artist
• 

  Walter Soyka

  October 18, 2011 at 2:06 pm

  [Jason Parekh] “I’m aware I could paste my expression eight times in the larger composition, but I was wondering if there’s a way I could achieve this without resorting to that. Ideally, inside the reusable composition’s expression, I could have a variable that’s a unique ID for that instance.”

  After Effects doesn’t have a concept of instancing per se, as many 3D apps do.

  You will have to apply the expression to each of the 8 precomp layers within the master comp.

  However, you can generalize the expression (so you can use the exact same code for all 8 copies of the precomp) by using the layer’s index attribute [link] (its layer number) to drive the parameters you want to change.

  Walter Soyka
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