1. 样条:
样条曲线是一种数学表示,很容易构建一个界面,允许用户设计和控制复杂曲线和曲面的形状。
2. B样条:
B-Spline 是一个包含一组控制点的基函数。 B-Spline 曲线由具有有限灵活性的 Bernstein 基函数指定。
3. 贝塞尔:
这些曲线由边界条件、特征矩阵或混合函数。贝塞尔曲线部分可以由任意数量的控制点填充。要逼近的控制点的数量及其相对位置决定了贝塞尔多项式的次数。
样条曲线、B 样条曲线和贝塞尔曲线之间的区别:
Spline | B-Spline | Bezier |
---|---|---|
A spline curve can be specified by giving a specified set of coordinate positions, called control points which indicate the general shape of the curve. | The B-Spline curves are specified by Bernstein basis function that has limited flexibiity. | The Bezier curves can be specified with boundary conditions, with a characterizing matrix or with blending function. |
It follows the general shape of the curve. | These curves are a result of the use of open uniform basis function. | The curve generally follows the shape of a defining polygon. |
Typical CAD application for spline include the design of automobile bodies, aircraft and spacecraft surfaces and ship hulls. | These curves can be used to construct blending curves. | These are found in painting and drawing packages as well as in CAD applications. |
It possess a high degree of smoothness at the places where the polynomial pieces connect. | The B-Spline allows the order of the basis function and hence the degree of the resulting curve is independent of number of vertices. | The degree of the polynomial defining the curve segment is one less than the number of defining polygon point. |
A spline curve is a mathematical representation for which it is easy to build an interface that will allow a user to design and control the shape of complex curves and surfaces. |
In B-Spline, there is local control over the curve surface and the shape of the curve is affected by every vertex. | It is a parametric curve used in related fields. |