ADOBE AFTER EFFECTS: Forum Expressions Tutorials Creative Cloud

# spinning around a null stay oriented up

FAQ   •   VIEW ALL
 spinning around a null stay oriented up on Jul 29, 2011 at 2:28:04 pm

I feel like I've done this before, but I'm completely blanking...I feel like I may have even asked this question before, so I'm sorry if I'm repeating myself! :)

I have 5 layers in a circle design that need to stay upright as they spin around a null. No 3D, very simple...at least it should be :)

 Re: spinning around a null stay oriented upon Jul 29, 2011 at 2:39:24 pm

Use an expression to set their rotation to the inverse of the rotation of the null:

`-thisComp.layer("Null 1").transform.rotation`

This tells each of the children to rotate in the opposite direction the parent is rotating (at the exact same rate). The two rotations will counteract each other, and the children will remain upright.

You will want to make sure that the children's anchor points are centered -- otherwise you will get some bizarre but (possibly very cool) spirographic motion.

Walter Soyka
Principal & Designer at Keen Live
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
RenderBreak Blog - What I'm thinking when my workstation's thinking
Creative Cow Forum Host: Live & Stage Events

 Re: spinning around a null stay oriented upon Jul 29, 2011 at 2:49:14 pm

Thanks walter, but all this does is rotate the objects in the opposite direction that the null spins. If I parent the layers to the null they are expressed to, they just stay still...

not quite there...

 Re: spinning around a null stay oriented up - nevermindon Jul 29, 2011 at 2:52:35 pm

I forgot I had changed the anchor point...nevermind. THANK YOU for your help!

 Re: spinning around a null stay oriented up - nevermindon Jul 29, 2011 at 3:04:00 pm

[Jason Brown] "I forgot I had changed the anchor point"

That's critical -- the idea is that the individual objects must rotate about their own centers contrary to the global rotation.

[Jason Brown] "THANK YOU for your help!"

You're welcome!

Walter Soyka
Principal & Designer at Keen Live
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
RenderBreak Blog - What I'm thinking when my workstation's thinking
Creative Cow Forum Host: Live & Stage Events

 Re: spinning around a null stay oriented upon Jul 29, 2011 at 3:10:24 pm

I knew I had done this awhile ago...so I did a search