the expression of the eyes of a character is usually a reflection of the personality of a character, the personality of a character is a reflection of the world or the universe in which the character lives or his experience that he has lived. if you take max, that his mother brings customers in his shabby apartment located in a poorly attended area, max would not be a nice little stupid boy, max could be the pimp of his mother and sister but it remains a variant of other. what I mean is that DS for BB has given a basis for it's personal to you to have them evolved as you feel and given them an expression of weak or possessed or worked over expressions with the many adon put on the marketIt seems like most of the characters' renders in the game tend to have a certain expression in the eyes that's sort of seductive or sleepy or stoned or I don't know what to call it. Has anyone pinned down the settings for that? Not that I necessarily want to use them in my renders, but more for the sake of completion.
you must know that a human being when he is sad has a tendency to narrowed his eyes and frowns the opposite when he is happy the eyes are wide open and the eyebrows go up on the forehead.
the best thing is to mimic the expressions in an ice, observed, and try to reproduce it, that's what I do. I also typed "facial expression" in google or "face expression mechanics"