1. A method for real-time facial animation, comprising: providing a dynamic expression model that includes a plurality of blendshapes and one or more corrective deformation fields; receiving tracking data corresponding to a facial expression of a user; estimating tracking parameters based on the dynamic expression model and the tracking data, wherein the tracking parameters include a plurality of weights for the plurality of blendshapes; and refining the dynamic expression model based on the tracking data and the estimated tracking parameters to produce a refined dynamic expression model, wherein the refining includes applying at least one of the one or more corrective deformation fields to each of the plurality of blendshapes.