We all feel like you need to create a combination of real and computer generated images. Roland, because of his experience, is quite clear on what he likes to see real and where he thinks it's best for the visual effects to take over. As much as we can, we want to shoot this for real. But what can you do for real? There's cars being dropped from cranes, smashing on the ground. So whenever we can get the real thing, we'll take it.
Featurette about the amazing special effects in 2012, by Roland Emmerich.