daros wrote:Stefano is working on this project just to learn how to model with subdivision surfaces.
I would like

, I would like just a hint as to how to start this model!

There is a module so is he box modeling it? Stefano's work looks good especially the subtle depressions up near the points. Very nice renderings.
Calatrava <--> Valencia, Milwaukee, etc. I am looking forward to visiting these sites.
Leonard