Thank you all for the appreciations .
Impressive execution of Sicklebrick whom I thank for the video.
You're right , it was really crazy those arches and even though I used a lot of copying and pasting the arch in the circular room of the funnel was particularly challenging and I had to redo it many times before getting a satisfactory result.
All in all it was a very interesting experience with hammer and your appreciation is like cake with cherries ... the greatest prize.
Once again I thank all the community TWP for the many tips and tricks that you write on the forum and in particular Josepezdj , author of ' exclusive water in the turrets room and to the teachings for create custom textures , HMW and DaMaGepy for solving various technical problems.
I uploaded the new version with some changes :
Trigger that opens the exit door is disable until enable the turrets .
The portal_clenser on the sidewalls do not cancel more portals and have only decorative effect.
In the final step I recommend using the zoom to open portal at the points indicated .
I used the portal_helper but do not seem to work properly if you shoot from the center of the room.
The turrets must be affected on the upper part to snap onPainted .
The video of solution provided:
http://www.youtube.com/watch?v=hnIZ-JURn_E