thank's for your answer. well, let't try to imagine. you have a painting of some century ago. the man on the canvass look at you in front but he is painted in a different angle of view.  for that reason you don't have any view about the missing part of the face. so, I need to build that part so as to create the entire face in order to buil an animation scene with this figure inside. here we go. if you are interested in knowing and looking at the painting plese make me know your e-mail and I send a good picture. very kind of you.  in the while let's see the attachment. (antonello da messina 1476  portrait of a man).