By discussing the property of interfaces base on differential geometry, the method of using enveloping surface to model the interfaces of surfaces can be obtained, and an example is given.

• 在讨论曲面之间形成的过渡曲面的性质的基础上,提出在立体造型中利用包络实现过渡曲面的步骤和计算方法,并给出了实例。