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 它們具有二次均勻b樣條基函數的性質,且用它們生成的分段多項式曲線具有與分段二次均勻b樣條曲線相同的結構和幾何性質。