We want to estimate the chord length Λ of a given rational Bézier curve efficiently. Since rational Bézier are nonlinear function, it is generally impossible to evaluate its length exactly. We approximate the length by using subdivision and we investigate the accuracy of the approximation Λn. In order to improve the efficiency, we use adaptivity with some length estimator. Additionally, we will...

In this paper, the issue of multi-degree reduction of Bézier curves with C and G-continuity at the end points of the curve is considered. An iterative method, which is the first of this type, is derived. It is shown that this algorithm converges and can be applied iteratively to get the required accuracy. Some examples and figures are given to demonstrate the efficiency of this method. 2011 Els...

Arc splines are G continuous curves made of circular arcs and straight-line segments. They have the advantages that the curvature of an arc spline is known and controlled at all but a finite number of points, and that the offset curve of an arc spline is another arc spline. Arc splines are used by computer-controlled machines as a natural curve along which to cut and are used by highway route p...

The reverse order laws for {1,3,4}-generalized inverses of a product of two operators have been studied by Wang et al. [J. Wang, H. Zhang, G. Ji, A generalized reverse order law for the products of two operators, Journal of Shaanxi Normal University, 38 (4) (2010), 13–17]. In this paper using a block-operator matrix technique we study mixed-type reverse-order laws for {1,3,4}-generalized invers...

In this paper we present a local fitting algorithm for converting smooth planar curves to B-splines. For a smooth planar curve a set of points together with their tangent vectors are first sampled from the curve such that the connected polygon approximates the curve with high accuracy and inflexions are detected by the sampled data efficiently. Then, a G1 continuous Bézier spline curve is obtai...

A class of cubic Bézier-type curves based on the blending of algebraic and trigonometric polynomials, briefly CAT Bézier curves, is presented in this paper. The CAT Bézier curves retain the main superiority of cubic Bézier curves. The CAT Bézier curves can approximate the Bézier curves from the both sides, and the shapes of the curves can be adjusted totally or locally. With the shape parameter...

We present an efficient geometric algorithm for conic spline curve fitting and fairing through conic arc scaling. Given a set of planar points, we first construct a tangent continuous conic spline by interpolating the points with a quadratic Bézier spline curve or fitting the data with a smooth arc spline. The arc spline can be represented as a piecewise quadratic rational Bézier spline curve. ...

The objective of this paper is to provide an ef®cient and reliable algorithm for representing and evaluating the boundary of the interval Be Âzier curve in 2-and 3-D. The boundary of the planar Be Âzier curve is represented by a sequence of Be Âzier curve segments with same degree and line segments in the order they are encountered when marching counterclockwise along its boundary. The boundary...

We present the result and accuracy comparison of generalized positivitypreserving schemes for triangular Bézier patches of 1 C and 2 C scattered data interpolants that have been constructed. We compare three methods of 1 C schemes using cubic triangular Bézier patches and one 2 C scheme using quintic triangular Bézier patches. Our test case consists of four sets of node/test function pairs, wit...

Spiral segments are useful in the design of fair curves. They are important in CAD/CAM applications, the design of highway and railway routes, trajectories of mobile robots and other similar applications. Cubic Bézier curves are commonly used in curve and surface design because they are of low degree, are easily evaluated, and allow inflection points. This paper generalises earlier results on p...