Hi there tilman.

You will still need to do a matchmove to integrate live actors into a 3D environment, as you will still need the replicated camera move for it all to work. What you would essentially do is matchmove the blue/green screen environment that the actors have been filmed on (this is how it is done in the industry), then the 3D environment can be set up using the same camera move, and put all together in post. There is a thread on this forum that I've put a fair bit of stuff about maya live on, if you have a search for it (sorry, I'm being lazy to put the link, just got back from a week in the sun and am feeling a bit whacked out).

If you have any specific questions, feel free to PM me and I'll try to reply quickly as I can.

LisaG :p