James Cameron has revealed that he has started working on the script for Avatar 2, and wants to start the shooting of the sci-fi follow-up by the end of 2013.“I want to get these scripts nailed down. I don’t want to be writing the movie in post production. We kind of did that on the first picture, I ended up cutting out a lot of scenes and I don’t want to do that again,” Contactmusic quoted Cameron as saying.“I’m in the Avatar business. Period. That’s it. I’m making Avatar 2, Avatar 3, maybe Avatar 4, and I’m not going to produce other people’s movies for them,” he said.