Naughty Dog has been more than happy to explain to us how complicated it is to have a moving character on a moving surface, like on the floor of a collapsing building or the top of a moving train. But we have no idea how to quantify these things. We play games ... we're not math and physics experts. But if you have a barrel that needs blowing up, or a crate that needs smashing open, we're your guys.

Uncharted 2's creative director Amy Hennig explained that most game levels tend to use a moving background that makes the object your character is standing on appear to be moving, and then augment that with physics. Not so with Nathan Drake. He gets to clamber over fully-modeled train cars and diveroll through actual collapsing buildings. No smoke and mirror tricks for this fortune hunter.

To prove the point, the developer showed us a live demo of the game where Drake hauls himself onto the back of a speeding train while simultaneously fending off baddies on the train, and a heavily-armed helicopter that decides Drake needs to be swatted off. You'll have to fight your way forward towards an RPG if you want to survive. Hint: there's a loud, whining noise before the chopper fires its rockets, and also watch out for low-hanging lights.

All of this takes place on a fully modeled and realized moving train, and it looks gorgeous, but we'll just have to take Naughty Dog's word for it as far as the mega-model railroad set that was design for this. Or, you can see what you think! Check out the new footage just after the break.

This article was originally published on Joystiq.

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