【摘要】 曲面延拓是将曲面沿着自身曲率变化趋势向外进行拓展的一种方法,在几何造型、计算机辅助图形学和模具设计中有广泛的应用。传统CAD软件针对拓扑结构复杂的曲面数模不能直接进行延拓。提出了一种延拓思路和方法,对于给定的曲面先对其内部的孔洞及裂缝进行判断和处理,处理后的曲面再通过粗等距的方法,简化其内部拓扑结构,用简化拓扑结构的曲面代替原曲面完成曲面延拓操作,获得延拓部分,延拓部分与原曲面通过桥接光顺地过渡连接起来,完成曲面延拓。事实证明,该方法可以将一些原本不能直接通过CAD软件直接延拓的曲面快速延拓。更多还原

【Abstract】 The surface extension is a method to make surface expand outside along its trend of curvature change,which is widely applied in geometric modeling,computer aided graphics and mold design. Traditional CAD software can not be used to make direct extension for surface curved model with complex topological structure. The article proposes a train of thought and method for extension,which are used to make judgment and processing on the internal holes and crack of the given surface,simplifies the internal topological structure of the processed surface with rough equidistance method; uses the simplified topological structure surface instead of original surface and completes the extension operation to obtain the extended part; connect the extended part to original surface with bridge pattern to transit and complete the surface extension. It is proved that this method can be used to make quick extension for surfaces that can not be directly extended by CAD software.更多还原