This paper describes a contrained fairing method for implicit surfaces defined on a voxelization. This method is suitable for computing a closed smooth surface that approximates an initial set of face connected
Esteve, J.; Vinacua, A.; Brunet, P. Piecewise algebraic surface computation and smoothing from a discrete model. "Computer aided geometric design", Agost 2008, vol. 25, núm. 6, p. 357-372.