车型CAD中的曲线和曲面造型

在汽车，船舶和模具等的计算机辅助设计当中，复杂曲线和曲面的设计始终是一个核心问题，三次Ｂ样条曲线是一种由给定的控制顶点所形成的控制多边形定义生成的自由曲线，具有Ｃ１，Ｃ２连续性，局部修改性及可扩展性等许多优良特性。

The Moulding of Curve and Curve Surface in the Computer Aided Design of Car Form

The design of complex curve and curve surface is all along the core in the CAD of automobile,ship and die.By applying cubic B spline curve and Coons curve surface,the authors succeed in designing contour of sedan body in the Auto CAD R13 environment.Cubic B spline curve is generated in the light of the defination of control polygon which is formed by the given control vertexes,this free curve is of C 1 and C 2 continuity and it is locally amendable and extensible.Coons curve surface is constructed by four given boundary curves with their 16 coefficient vectors totally,this curve surface sheet is capable of creating the curve surface to meet the needs by way of overlay and correction.