其中曲线拟合是一个在给定误差下进行曲线逼近的过程，当曲线拟合完成之后，整个曲面的控制点的数目也就确定了。
Curve fitting is a curve approaching process under definite error and the number of control points throughout surface is ascertained after curve fitting completed.
文中根据曲线曲面型值点，分别用四种参数化方法构造节点矢量，利用NURBS方法反算控制点。
In this paper, the control points are calculated based on the curve or surface's data points and the knot vector which is calculated with four kinds of parameterization by the method of NURBS.
样条曲面具有灵活性，概念简单，易于通过操作控制点控制形状，所以对于自由曲面建模十分重要。
Spline surfaces are very important for the modelling of free form surfaces, because of their flexibility, simple concept and easy shape manipulation by the control points.
NURBS方法在实际应用中遇到的一个重要问题就是已知曲线曲面上的型值点而求解控制点。
An important problem which is brought about by the method of NURBS in practice is that calculating control points based on the curve or surfaces data points.
利用等距曲面原理，推导出求解面层以下其他结构层控制点坐标的计算公式。
The calculation formula is made in terms of the every control point of the structural layer beneath the pavement by means of the principle of the curved surface with equal space. The applying tech...
相切是由曲面边界的最初两个控制点控制的（假设这些点在一条线上）。
Tangency is controlled by the first two control points from a surface boundary, assuming that these points lie in one line.
相切是由曲面边界的最初两个控制点控制的（假设这些点在一条线上）。
Tangency is controlled by the first two control points from a surface boundary, assuming that these points lie in one line.
应用推荐