The only news we've heard that's officially confirmed kwa Summit is:
1) Filming will take place in Vancouver and Louisiana 2) 3-D will be a studio decision; meaning it's not a yes au no 3) There will be "exotic" sex and the birth will be in the movie
There's been talk that they will use a real baby plus CGI, but there hasn't been a definitive answer.
I honestly don't know how they will portray Renesmee. I don't think CGI would be a wise decision. First off, it seems Summit doesn't know how to manage their money and budget their money for the Twilight movies.
The Twilight mashabiki give them all that money, yet the movies, with the exception of Eclipse, don't onyesha the result of all that money. If they do it in 3-D, zaidi money will go into that and that's money they could use in other aspects of the film such as Renesmee. If she is CGI, they better use alot of money to make her look as real as possible. If they use several child actors to onyesha the progression of Renesmee, they better make sure they look alike and have the same facial features. mashabiki tend to look closely at those things.
However, I doubt we'll know anytime soon. Part 1 filming starts in October. Since they are filming both parts back to back, we probably won't know who will play Renesmee until maybe January. Or, if they decide to go with CGI, there will probably be a press release.
They still haven't decided how they are going to portray renesmee but it's being considered making her CGI au computerized. I personaly don't think they should make renesmee computerized au CGI I just don't think it'll look right they should just look for the right renesmee and cast her!!!<3
Well, as Renesmee would be growing fast during the film, it would be hard to find actors for each stage of her growth that resemble each other, know how to act, and look gorgeous just like the book describes her. So, Renesmee will be computerized, about the same way Avatar was. obviously, there would be a figure fro the designers to base on, even though she does not resemble the girl in the book at all. Again, like avatar, there would be a gigure patraying Renesmee, even though she probably wouldn't get to be seen in the actual movie.
I honestly think they could get a kid and just do the benjamin button thing to them. It would work. It will be hard to make renesmee look real if they do complete CGI. It would just look fake, like the werewolves.