How to Converge/Diverge Objects Away from Center Null

[Justina5E96]

Hello!

First time posting in this forum so apologies if I'm missing anything to provide a helpful discussion.

I'm working on a balloon head made out of individual Xs which are all in individual layers. Since there's quite a few layers, I was hoping to somehow connect the position of each X to a null object in it's center that would converge/diverge to simulate the balloon popping. Additionally, the artwork is not symetrical, so I don't believe I would be able to use mirror effects to achieve what I'd like.

My first thought was to create an expression with the position of each X related to the null object's scale, so that they would hopefully radiate out in different directions based on their starting position in relation to the null. I'm struggling to know where to begin in writing an expression for these properties. Potentially using the difference in scale to move the position by a certain factor, but I'm unsure how to make a universal expression to move the Xs omnidirectionally.

Any advice would be greatly appreciated and happy to provide more info on the composition that would be helpful!

[thepixelsmith · Accepted solution]

I may be missing the point but it sounds like you want to like the position of the "x" layers to the scale of a cnetroal null?

Maybe something like in this turtorial: https://youtu.be/YwNt6UoLjhk?si=MeSBLsNYTKl8EzMp

[Justina5E96]

Thank you for sending this over! The script from this video seems to be working perfectly. The positions of the Xs are moving without changing the scale of the Xs themselves. I wish I had found this tutorial sooner after a few hours of searching haha

[Dan Ebberts]

Have you tried just parenting all the x's to the null? Then when you scale the null up the x's will all move away from it, proportionally.

[Justina5E96]

Unfortunately, this also changes the scale of the Xs themselves which I would like to keep the same.

[Dan Ebberts]

Yeah, I should have picked up on that. A simple version of the anti-parent-scale expression, (which assumes no grandparents, uniform scaling of the parent, and parent scale will never be zero) would be like this:

hasParent ? value/parent.scale[0]*100 : value