摘要:NURBS 曲面自由型特征因不具有确定的参数、准确的边界,使其表示、编辑及操
作十分困难。基于一种新的小波多分辨率分析技术将NURBS 曲面从单一尺度几何表示的空域
变换为频域的表示形式,借助于滤波器组将模型的整体结构和局部细节变换为其全局和局部多
分辨率自由型特征,实现了对NURBS 曲面的自由型特征的编辑、操作和控制。该方法不仅能
提高NURBS 曲面几何建模的效率,而且可以克服传统NURBS 曲面建模的繁琐和费时。
Abstract: Because of imparametrization and no determinate boundary of a NURBS surface with#br# free-form features, representing, editing or operating them is still troublesome. The multi-resolution#br# representation of a NURBS surfaces is realized by a new kind of wavelet multi-resolution analysis#br# technology, and representation of the NURBS surfaces is transformed from single-scale geometric#br# space to multi-scale frequent space. Through wavelet filter banks, the total configurations and local#br# details of models are transformed to total and local multi-resolution free-form features. This makes it#br# easy for editing, operating, and controlling a NURBS surface. This approach not only raises#br# efficiency of the NURBS surface geometric modeling, but also overcomes miscellaneousness and#br# troublesomeness in the conventional modeling.