Subdivision surface fitting with QEM-based mesh simplification and reconstruction of approximated B-spline surfaces

We present a general method for automatically reconstructing a network of B-spline patches based on the Doo-Sabin subdivision surface. This method consists of two parts, surface fitting and surface construction. In surface fitting, mesh simplification based on QEM (Quadric Error Metrics) is used and a control mesh that approximates a Doo-Sabin subdivision surface is constructed. In surface construction, we define a B-spline surface using a surface spline method; and a constructed network of B-spline patches is guaranteed G/sup 1/ continuous. In addition, this method has the advantage of enabling the user to select detail levels of the control mesh by utilizing a mesh simplification process.