Sorry if this is not the right place to ask this question but it's really bugging me and I just want to know.
It's about green screen in films and possibly adding 3d back grounds.
I've seen the techniques in film when an actor will stand in front of a green screen and then a 2D back ground is added after. But what about a 3D back ground? I've seen some things on you tube with motion tracking and people adding things on tables that wasn't there before, or rings around a pole doing a little shimmy.
What I was wondering was how do they make fully 3D back grounds and have the actor interact with them perfectly? I'm sure 80% (or close) of the newer star wars films were mostly 3D and I've seen pictures of Obi Wan on a green screen set on a green bridge.
So do the modellers just add the bridge in after? and texture it? What kind of program is used? I guess that's the main gist of what I'm trying to ask; How do you make massively 3D sets that look real when all three elements are moving at the same time, I.e. -
Moving 3D background
Thanks in advance.