Yeah I thought that too Pilou, but hide the edges and it's not so smooth :(
I'm also aiming for tangency to the 3 initial surfaces. I think in other apps, there is like a surface patch tool that does the job, but I'm not sure.
I used a different method, I just wanted to see if anyone else comes up with the same method or better.



Oh yeah, being with this forum you tend to learn some technical French terms, so don't worry I knew what Gordon was ;)

Cheers