In How do I draw a pair of buttocks? there is a discussion how to draw a human backside. It shows an example of Manipulate to ParametricPlot3D this part of a body.
In this discussion they were targeted to solve the problem using analytical, especially trigonometric functions to achieve typical surface shapes. Now I would like to direct the attention to a higher topic: I am curious if there is any model with some free parameters to show typical human faces. Restricting oneself to analytical functions most probably will lead to no result. I am surprised how far they got in the buttocks-example.
A particular human face definitely can be represented e.g. by NURBS surfaces. In face recognition some typical points are recognized in order to represent a particular face by a few distinguishing numbers. Since face recognition from images also works when an unknown face is presented to a camera in a range of orientations in space, I suppose that in the background there must be some parametric model of typical faces, probably with a low number of adaptable parameters to distinguish one and the same face with different expressions from other faces, also with different expression parameters and also with some skewness in the whole face.
So arises my question if someone already has produced some model ready for Manipulate to generate different faces (e.g. with different distance between the eyes, hight of the forehead, lenght and width of the nose (and other nose parameters), different width of the cheekbone, the chin and the like and perhaps parameters if the face is smiling, grimming or sad. Some model that would be apt for a police officer interrogating a witness how the searched subject would look like and by influencing the parameters in his discussion with the witness one after another until the face fitting best to the memory of the witness finally is achieved