简介¶
Curves and Surfaces are particular types of Blender objects. They are expressed by mathematical functions (interpolation) rather than linear interpolation between a series of points.
Blender同时提供 Bézier 和 NURBS 。贝塞尔曲线，NURBS曲线和曲面都是根据一组“控制点”（或“控制顶点”）定义的，这些点定义了一个“控制多边形”。
贝塞尔曲线制作的Blender logo。
贝塞尔曲线和NURBs曲线都是以其数学定义所命名，选择使用哪种曲线往往更多考虑的是其后台计算方式，而非从建模者的直观角度考虑。贝塞尔曲线通常更直观，因为其起始点均为控制点，但NURBs曲线在描述有许多波折的曲线方面更高效。
使用曲线而非多边形网格的主要优势是，曲线使用更少的数据来描述物体结构，所以在建模时可以使用更少的内存和存储空间来产生结果。然而，此方法所建的曲面会增加渲染时的负担。
Certain modeling techniques, such as extruding a profile along a path, are possible only using curves. On the other hand, when using curves, vertex-level control is more difficult and if fine control is necessary, mesh editing may be a better modeling option.
贝塞尔曲线是设计字母或logo最常用的曲线。
They are also widely used in animation, both as for objects to move along (see constraints below) and as F-Curves to change the properties of objects as a function of time.