Curve drawing method and system based on B spline and storage medium

Abstract

The invention discloses a curve drawing method and system based on a B spline and a storage medium. The method comprises: constructing a B spline expression, and inputting and interpolation points; performing centripetal parameterization on the interpolation points; determining an N primary function node sequence in the B spline expression; substituting interpolation points into a B spline expression by utilizing the N basis function node sequence to obtain a solving equation of a difference condition; calculating a solving equation based on the matrix to obtain a curve control point sequence;and drawing a curve by using points in the control point sequence. According to the method, the curve is drawn based on the B spline function, the method can better adapt to drawing of common edge contours, the expression is a low-order polynomial, and the calculated amount is small; based on the expression ability of the spline, a user can draw a complex curve by setting interpolation points, and the operation is convenient; and adding the same vector based on the head and tail end points to meet the smoothness requirement of the closed curve.

Description

technical field [0001] Embodiments of the present invention relate to the technical field of computer-aided geometric design, in particular to a B-spline-based curve drawing method, system and storage medium. Background technique [0002] CAGD is widely used in industrial manufacturing and geometric modeling. Among them, the mathematical method has formed a complete system (NURBS) and is generally adopted by the industry. Interpolation technology has a long history as a technology, and there are various interpolation forms. In work, low-order piecewise polynomials are often required to express the curve we want, and the curve must meet specific smoothness and boundary requirements. [0003] In the current research, for the curve whose edge of the target area is not a straight line, the generally used polygonal polyline needs to draw a lot of interpolation points, and it cannot fit well the curved contour edge. And the smoothness of the broken line segment is not enough. ...

AI Technical Summary

Problems solved by technology

[0003] In the current research, for the curve whose edge of the target area is not a straight line, the polygonal polyline generally used needs to draw a lot of interpolation points, and it cannot fit the curved contour edge well.

And the smoothness of the broken line segment is not enough

In addition, it is difficult to implement the existing polyline segment method for drawing a curve with the same shape after radial scaling

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