关键词: 有理B样条曲线, 形状, 权因子

Abstract: The rational B-spline curves are developed for unity expression of the free curves and the taper curves. It is the same as multinomial of the B-spline curves. It is also an approached type and the visual geometry is fine. To adjust the control points can control the shape modification, at the same time, the weights of the every control points of rational B-spline curves provide a new way of the shape modification. But the potential of weights have not attracted special at-tention. In this paper, the method for shape modification of rational B-spline curves is presented. The combination of changing weight, moving control points, inserting knots are made for fast, reliable and very accurate shape handling.

Key words: rational B-spline curve, shape, weight