Though smoothness of surfaces is one of the main goals in free-form surface modeling, non-smooth effects, such as sharp features, are required in some occasion. Generation of them is investigated in this paper. A method based on the construction of mesh topology is presented to unify the generation of the sharp features such as crease, corner, dart and cone into the method of boundary process. Thereby creating special subdivision rules is avoided for different effects, and thus the sharp features are realized without updating subdivision schemes.