Just a quick idea, you might be able to do it AE if you have a precomp with a bunch of circles filling up the comp. Then you could use a larger circle on top of it and use it as an alpha mate for the shapes underneath. That would give you the shape cut out of the smaller circles underneath.
I’m sure there’s a better way then that though probably using some expression but I’m not sure what.
Another idea just came to me you could use the Cocoe Battalion expression to fill an object based on mask shape. I used it to trace and outline of circle target for an animation I did.
RIT SportsZone Web Extras Bump
In C4D you could just use a cloner set to an object mode then just clone a bunch of smaller objects into the shaper of the larger one. There’s few different options like volume or vertex you can use to get it filled the way you want.
Greg