Voice Talent: Actors control the avatars during shooting, setting off gestures, animations and movement as needed for the scene. Timing is managed to fit the dialog. Often, however, the actors won't be the voice of the character in the movie. This is because male actors might be operating female avatars or vice-versa, one actor/avi may be playing several roles in the movie, and so on.

So, each character in the film also has a voice actor to speak the lines. The voice-over recording is done via Skype, often after the scene has been cut (edited) together, but sometimes before.

Voice actors can be present during the filming of the scene if they like (and if they have the Director's permission), but they don't actually do anything during the filming. Voice talent works in the post-production stage.