There exist many "impossible" combinations of AUs, let's say 45+46 for example or 18+27 etc. i.e. combinations of AU that can not possibly be expressed because they "occupy" the same area of the face or are opposites of each other. Is there a list somewhere that shows what AUs can be combined together and further what kind of emotion they convey (apart from the 7 base emotions) or whether they form an expression that is at all "meaningful"?
Alternatively: A software that can display a picture of a face with a certain expression on it, after given the specific AU codes for that expression. Does something like this exist?
Thanks in advance!