Offset Pattern

I am trying to obtain a pattern like the one in the image.

Starting point is the green curves. I would like to offset these green curves multiple times and to merge the offset curves when they collide.

What would be an effective way to do this?

I would suggest Bowerbird - the BB Offset component is pretty good at this sort of thing

Thanks, I will try this.

I think clipper also works for this case.