You CANNOT copyright your face. There is a whole industry of Celebrity impersonators you know. I fail to se any difference in creating a digital doppelganger of a real actor. That being said if you make a double of something that was originally Drawn, painted, sculpted or modelled, that may be a different issue. Personally I'd never ask the creator (more like the many corporations that have their grimy hands in the pot) as some lawyer is always gonna advise em to say no. Better to just do it, then hop to if they send you a cease and desist... which isn't very likely anyway.