Efficient region-selective subdivision for 3-D meshes

An efficient region-selective subdivision algorithm for 3-D meshes is proposed in this research, The use of subdivision surfaces for constructing and representing 3-D objects has been introduced in computer graphics and related fields. As an interpolating subdivision scheme on triangular meshes, the modified butterfly subdivision (MBS) algorithm is feasible for many applications such as progressive rendering and object shape-preserving. To further improve MBS, we adopt efficient refinement criteria based on the viewing frustum, the surface orientation, the screen-space visibility error and the local mesh flatness. We also provide a set of subdivision rules to model some natural sharp features such as local creases, cusps and darts. By choosing appropriate edges as being sharp, the refined meshes attain desired sharp features in edge regions, while maintaining the same order of smoothness as other subdivision algorithms elsewhere.