Hi Florian,

you're right, i missed your post about! many thanks for the answer! i've read the message and now i'm gonna try to do that: i've understood you work like this

- make a grid with GH on the surface, and set up the circole in each peaces of surface the grid do, then the curve attractor that transform cicle from small up to big (ref the distance)

- than you bake it and use the command Split of Rhino to create holes so you have your pierced surface you can after extrude and work as you want!

Thanks again! you're very kind to answer me, the new dummy of the situation! :-)

Tommi