讨论了球域张量积Bézier曲面的降阶问题。为了简单起见,只考虑了次数(m,n)的Bézier曲面的降阶到次数为(m-1,n-1)的情况。在降阶逼近过程中,要求低阶的张量积Bézier曲面为原有曲面的闭包。与已有的算法相比,该算法具有计算简单、逼近误差直接给出,几何直观性强等优点。
The problem of degree reduction of ball control points Bézier surface is discussed.For the simplicity,only the de-gree reduction from(m,n) to(m-1,n-1) is discussed.In the approximation processi,t is required that the lower-degree ball control point Bézier surface is closure of the given surface.Compared with the algorithms in the pastt,he new algorithm com-putes simplyt,he error tolerance is got directly,possesses stronger geometric explanation.