This paper presents a method of determining the approximate swept volume of Non-Uniform Rational B-Spline (NURBS) surfaces or solids. The method consists of (1) slicing the NURBS surfaces or solids by finding the intersection of plane/surface; (2) forming the sliced curves; (3) setting up the local moving coordinate system; (4) determining the characteristic (also called singular) points or cur...

Symbolic computation of NURBS plays an important role in many areas of NURBSbased geometric computation and design. However, any nontrivial symbolic computation, especially when rational B-splines are involved, would typically result in B-splines with high degrees. In this paper we develop degree reduction strategies for NURBS symbolic computation on curves. The specific topics we consider incl...

Existing data embedding algorithms for polygonal meshes and their attributes can’t be applied to the majority of (geometric) computer aided design (CAD) applications, for two major reasons. First, these CAD systems employ parametric curves and surfaces, not polygonal meshes, as their main shape-defining primitives. Second, most CAD applications do not tolerate modifications of model topology an...

We deal with subdivision schemes based on arbitrary degree B-splines. We focus on extraordinary knots which exhibit various levels of complexity in terms of both valency and multiplicity of knot lines emanating from such knots. The purpose of truncated multiple knot lines is to model creases which fair out. Our construction supports any degree and any knot line multiplicity and provides a model...

GeoPDEs (http://geopdes.sourceforge.net) is a suite of free software tools for applications on Isogeometric Analysis (IGA). Its main focus is on providing a common framework for the implementation of the many IGA methods for the discretization of partial differential equations currently studied, mainly based on B-Splines and Non-Uniform Rational B-Splines (NURBS), while being flexible enough to...

A new approach for the geometrical optimization of five-axis-movement is presented in this paper. Regarding a fiveaxis-movement with large tolerances for lead and tilt-angle for example in the case of laser-cutting there are endless ways of generating motions without violating the orientation-tolerances. By regarding the movement of the involved axes it is shown that for a given 5-axis trajecto...

A new formulation of energy minimising splines, based on Non-Uniform Rational B-Spline (NURBS) curves, is presented. The existing snake models do not facilitate the local control of their shapes without increasing the number of control points. The introduction of NURBS renders more flexibility into the snake model due to the weighting parameters that are made to adapt according to the curvature...

NURB (Non Uniform Rational B-spline) curves and surfaces are being used to solve curve and surface tting problems i.e. where a sequence (or an array) of points is given and then one can nd a NURB curve (or an surface) that interpolates to the given data. In general one has to provide additional information, called end conditions to solve the system of equations in the NURB interpolation problem...

In this article, by using Chebyshev’s polynomials and Chebyshev’s expansion, we obtain the best uniform polynomial approximation out of P2n to a class of rational functions of the form (ax2+c)-1 on any non symmetric interval [d,e]. Using the obtained approximation, we provide the best uniform polynomial approximation to a class of rational functions of the form (ax2+bx+c)-1 for both cases b2-4a...

Non Uniform Rational B-splines (NURBs) are proved to be very promising for metamodeling in engineering problems, because they have unique properties such as local modification scheme, strong convex hull property, and infinitely differentiability, etc. Since NURBs are defined by control points, knot vector, and weights associated with control points, the precision of NURBs is influenced by all o...