in addition, parameterised form allows us to compute the precise parameterized surface's derivative, except the point ( 0, 0 ) 另外,得到的参数化格式可以计算曲面在除(0,0)点外的任意参数处的任意阶导数的精确值。
through analysing and computing the surface parameter, we have obtained arbitrariness sub-surface parameterised form nearby the extraordinary points, which can quickly efficiently and precisely compute all the sub-surfaces 通过对曲面参数化的分析、计算,得到了特征点附近的任意子面片的参数化格式。