Constructing rational offset and rational Rotation-Minimizing Frame of Bezier curve or B-spline curve during rendering sweep surface which are compatible with CAD system are two important problems in CAGD.

• 等距(Offset)有理构造与扫掠曲面生成中的最小旋转标架(Rotation-Minimizing Frame简称RMF)的有理构造是CAGD研究领域中的两重要内容。