Revealing mistake: As the emperor raises his army, you see the holes form into the ground and the armies march. After a close up and the camera pans to get a larger view, watch closely and you can see the army take a totally different formation, caused by a computer generator. (01:19:40)
Suggested correction: After rewatching, I'm going to correct this a second time just to clarify. I think the OP is referring to the fact that there's a fade in the middle of the shot where suddenly the camera moves out more and we see more soldiers. That's not an "error caused by a computer generator." That's the filmmakers using a fade to imply a slight passage of time, which is not a mistake in any way, shape, or form. Additionally, as I said in my initial correction, the scene is subtly cut in a montage-like style to show the army rising quickly without having to see every single second of it, since it would take way too long and would kill the movie's pace.
Suggested correction: The scene is edited using montage-style editing. (Including obvious fades and time-jumps.) It would take far too long to show the scene start-to-finish in real-time. The fact that the formation changes between shots is acceptable within the context of a montage because a montage implies passage of time between edits.
