1. A computer-implemented method of generating an anatomically-constrained model of a face of a subject, the method comprising: obtaining one or more three-dimensional shapes of the face of the subject; segmenting the face into a plurality of patches; determining a plurality of local shape subspaces for the plurality of patches, each local shape subspace including local shape deformation of a corresponding patch, wherein a local shape subspace for a patch includes a plurality of deformation shapes for the patch, and wherein a deformation shape of the patch defines a deformation of the patch for a facial expression; determining an anatomical subspace, the anatomical subspace including tissue thickness constraints for the plurality of patches and an anatomical bone structure, the anatomical subspace globally constraining local shape deformation and tissue thickness for the plurality of patches, wherein the patch is constrained by the anatomical bone structure using one or more tissue thickness constraints determined for the plurality of deformation shapes of the patch; and generating the anatomically-constrained model of the face by combining the plurality of local shape subspaces and the anatomical subspace.