Bézier spline
From Free net encyclopedia
In the mathematical subfield of numerical analysis and in computer graphics a Bézier spline is a spline curve where each polynomial of the spline is in Bézier form. A Bézier spline is sometimes called bezigon as Bézier splines are like polygons but instead of straight lines they consist of Bézier curves.
Bezigons can be made big or small or rotated with no "jaggies". Adobe PostScript fonts are made up of bezigons. Bezigons can be used to create scalable shapes directly.
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Definition
Given a spline S of degree n with k knots xi we can write the spline as a Bézier spline as
- <math>
S(x) := \left\{ \begin{matrix}
S_0(x) := & \sum_{\nu=0}^{n} \beta_{\nu,0} b_{\nu,n}(x) & x \in [x_0, x_1) \\
S_1(x) := & \sum_{\nu=0}^{n} \beta_{\nu,1} b_{\nu,n}(x - x_1) & x \in [x_1, x_2) \\
\vdots & \vdots \\
S_{k-1}(x) := & \sum_{\nu=0}^{n} \beta_{\nu,k-1} b_{\nu,n}(x - x_{k -1}) & x \in [x_{k-1}, x_k) \\ \end{matrix}\right. </math>