There are definitely a few issues with it especially in the skin stretch and squeeze around the lips, nose, and cheeks areas. There are a lot of muscles and ski

There are definitely a few issues with it especially in the skin stretch and squeeze around the lips, nose, and cheeks areas. There are a lot of muscles and skin movement that’s supposed to happen and rendering that needs time and good attention to detail with the materials. But outside of that, there are the limits of rotoscoping coming into play. Human motion has a lot going on and our 3d captures aren’t anywhere near that kind of fidelity yet. Therefore we still need to rely on what the old masters of animation discovered when they were getting past the rotoscoped era. To make a performance more believable there has to be a little more acting and exaggeration brought in. The eyes can’t just get wider. They need to have anticipation, movement, secondary movement through other pieces of the face, etc. Same with the mouth. It’s not that the mouth can’t stretch in an abnormal way. It’s that it requires a little bit extra like a neck movement creating anticipation of an angry snarl. As far as we have gotten along with mocap tech, when it comes to film, there’s a loooot of hard work that goes into fine tuning done by professional animators to make the performance of each actor look good when it’s translated to the 3d character.