Hey Chris,
Thanks for the idea.
<font face=”inherit”>I created on Illustrator a layer with the ellipse grid complete and other three layers with some </font>ellipses<font face=”inherit”> subtracted (to create the transition between the complete to the incomplete grid). </font>
<font face=”inherit”>After that, I imported the AI file as a comp into AE, added on top of it a shape layer with the same ellipse grid (constructed using the repeat), masked it using the “set matte” effect and then, </font>finally<font face=”inherit”>, inside of the AI comp, I created the transitions with layer opacity. </font>
The strongest point of this approach is the fact you end up handling just a couple of layers (instead of my first approach with more than 1K layers; insane and stupid one, I know). The downside of it is creating the animation outside of AE.
Still, a much better option, thanks!