Dynamic Packing of Circles

Hi! 

I'm a new grasshopper user, and I'd like to find to way to randomly pack a plane surface with circles of user-defined sizes. I'd like to use Kangaroo with an iterative simulation, where I add circles one-by-one, while running the Kangaroo springs physic engine to pack the circles.

So it seems I have both loops and kangaroo running in the same time, but i can't figure the way to do it.

I've already looked at a few circle-packing definitions, but none of them seem to fit to what I'm looking for.

Any Idea ?

Many thanks