The most (in)famous part of “Breaking Dawn — Part 2” is Bella and Edward’s creepy CGI baby Renesme. Instead of using an equally terrifying doll, the film’s producers opted for CGI, with decidedly unsuccessful results. It’s one of the worst parts of a generally quirky movie, even if it kind of amuses us these days.
Fortunately, as Renesme grew, less and less CGI was needed to create his character. In fact, one of the biggest differences between Renesme in the books and in the movies is how quickly she grows up. In both versions, Renesme grows up very quickly due to being a vampire/human hybrid. At the end of the last book, she appears to be around two years old, although she is only a few months old. In the film, however, the older version of Renesme is played by actress Mackenzie Foy, who was 10 years at the time of filming.
While Renesme, a toddler, was an odd blend of Foy’s face with the face of a much younger child, the older version of Renesme is, thankfully, just Foy. It’s obviously more dramatic to see Renesme grow at an even faster rate than in the books, and this reduced the amount of CGI they had to use for his character, so we can’t blame the producers for making this particular change.