They have the properties like the quadratic uniform b - spline basis functions . the piecewise polynomial curves generated by the above - mentioned functions possess the same structure and geometry properties as piecewise quadratic uniform b - spline curve 它们具有二次均匀b样条基函数的性质，且用它们生成的分段多项式曲线具有与分段二次均匀b样条曲线相同的结构和几何性质。
