It's a movie about people who's been living nderground for quite a while, fooled that the world on the surface is dead. They have some kind of telescope they use to looke above ground but all they see is wasteland. However, some of them succeedes to get up and the wasteland is noting but a painting on the inside of a tent.
Some one is taking advantage of them, living alone in a perfect world on the surface in a big mansion. The world is green and just fine.
I can't seem to remember the name of the movie. Any help is highly appreciated!