Felice Varini's town-sized illusion

The buildings in the town of Vercorin in the Swiss Alps contribute to an impressive piece by Felice Varini, called Cercle et suite d'éclats. The pattern was projected on the town from the vantage point, then traced and painted. Photographs from the same spot in daylight make the town look flat, almost like a postcard. What I'd like to know is how he got the town to go along with it; I could see an easily-repainted suburb in the States being convinced, but this quaint (and much older) town in Switzerland seems like a much bigger challenge. Don't miss the panorama picture on Varini's site. [via Core77]