1. A method, comprising: causing one or more processors to perform identifying sets of two-dimensional local feature points on a face in each image of a set of images, wherein the set of images comprises a sequence of frames a video stream; and generating a three-dimensional face model for the face in the each image as a combination of a set of predefined three-dimensional face models, wherein said generating further comprises reducing an error between a projection of vertices of the set of predefined three-dimensional face models and the two-dimensional local feature points of the each image, constraining facial expression of the three-dimensional face model to change smoothly from image to image in the sequence of video frames, and representing each of the set of predefined three-dimensional face models using a three-dimensional tensor decomposition defined by a vector of coefficients representing an expression dimension that varies for each frame, and a vector of identity coefficients that is fixed across frames.