Hasta La Motion!

I was hired as a matchmove artist for an upcoming indie war movie. I completed all the matchmoves and handed them in. The director needed more hands on deck for compositing to meet his deadline for completion, so I offered to help out on the final comps.

Basically, the scenes were all filmed on a dirt lot in Tempe, AZ. The background is currently just cars, buildings and traffic lights, but it needs to be wiped out and replaced with an Iraqi city (which is CGI).

The issue is, I’m still very inexperienced. The cgi has already been modeled and placed using my matchmoves. But in terms of compositing it back in and making it look truly rooted, I don’t know all the little tricks and techniques. Set extension is an art in itself. I go to websites like Lynda.com and Digital Tutors, but none of them really teach any courses that focus around digital set extension. The other issue is digitally removing large elements from the shot that overlap into parallax shift and making it look convincing. I’m having some trouble with this as I don’t know anyone who has done set extension and nobody online seems to teach it.

This is getting long. I’ll get to the point. Does anybody have any sage advice for a greenhorn such as myself? If not, do you know any good tutorials for set extensions? I know video copilot has a tutorial where he does a background replacement using Photoshop and AE, but his shot was simple in concept because there wasn’t really any parallax shift for the elements he was laying in, so for that it was really just a matter of tracking it and throwing them in. The shots I’m working with are handheld style so there’s lots of side-to-side motion and parallax.

Any help would be much appreciated.

Thanks!