实体定义
曲面(GfcSurface),各种曲面基类。
继承关系
GfcRoot
└
GfcGeometry
└GfcSurface
├
GfcBevel
├
GfcCylinder
├
GfcPlane
├
GfcSphere
├
GfcNurbsSurface
├
GfcHelicoid
├
GfcSweep
├
GfcTorus
└
GfcRuledSurface