The Art of Expression: Analyzing FACS in Close-Ups

FACS (Facial Action Coding System) is a system for describing facial expressions using individual muscle movements called Action Units (AUs), instead of general emotion labels like “happy” or “sad.” It breaks the face into controllable components such as brow movement, eyelid tension, lip movement and cheek activation.
Even though it didn’t follow all 14 Action Units perfectly, it still interpreted most of them surprisingly well.
I think this could become especially useful for subtle facial acting, forced smiles, uncanny expressions, mixed emotions and micro-performance details during close-up dialogue shots.