This software is incredible. You feed it a 2D still of a face, and set paramaters like lighting etc, and the software compares it to its base model of faces and recognises the 3D geometry of that particular face.

Its pretty amazing stuff. They use the software to make faces in pictures (or paintings) talk. And adding 3D objects into the scene like a hat which casts shaows correctly on the nose/eyes etc. They make Tom hanks fat/skinny etc. And they even chaned the gender. All based on typical calculations from human faces.