The representation, matching and analysis of objects of interest are of prime importance in shape-based retrieval systems. Considering that these systems involve analysis of various complex shapes, an accurate representation of free form shape is required. A simple and accurate shape representation procedure would ensure meaningful results from the shape-based retrieval systems. Motivated by th...

Constructing a CAD model from a physical model plays a key role in some rapid product development processes. Presented in the paper is a method of ®tting NURBS surfaces for rotational freeform shapes: (1) cloud-of-points data (COP-data) representing a rotational freeform shape are transformed into an orthogonal coordinate system, (2) a single-valued B-spline surface is ®tted to the transformed ...

This paper presents a novel modeling technique and develops an interactive algorithm that facilitates the automatic determination of non-uniform knot vectors as well as other control variables for NURBS curves and surfaces through the unified methodology of energy minimization, variational principle, and numerical techniques. NURBS have become a de facto industry-standard primarily because of t...

Digitalization of agriculture bring controllable industrial production and computer-aided design ideas into agriculture, NURBS curves and surfaces is described freedom of widely popular technology, CAD systems are widely used. Method can be easily applied to generate curves, surfaces with NURBS. In this paper, we have developed model of cotton organs using NURBS surface, present a introduction ...

In order to solve the problem of trajectory planning robotic plasma cladding for complex surface coating, concept non-uniform rational B-spline (NURBS) function open-/closed-loop mapping is proposed firstly in this work explore new approach NURBS surfaces. The carried out by a 2D-NURBS curve C(u) on 2D plane, which mapped predefined 3D-NURBS S(u,v) using form 3D named (NURBS-FM) curve. Using fi...

Non-uniform rational B-splines (NURBS) have become a de facto standard in commercial modeling systems because of their power to represent both free-form shapes and some common analytic shapes. To date, however, NURBS have been viewed as purely geometric primitives, which require the designer to interactively adjust many degrees of freedom (DOFs )-control points and associated weights-to achieve...

We develop a dynamic, free-form surface model which is useful for representing a broad class of objects with symmetries and topological variability. The new model is based upon swung NURBS surfaces, and it inherits their desirable cross-sectional design properties. It melds these geometric features with the demonstrated conveniences of surface design within a physics-based framework. We demonst...

Generating valid tool path curves in NURBS form is important in realizing an efficient NURBS machining. In this paper, a method for computing one-sided offset approximations of freeform curves with NURBS format as tool paths is presented. The approach first uses line segments to approximate the progenitor curve with one-sided deviations. Based on the obtained line approximating curve and its of...

Resumen—Este artículo presenta un método para ajustar objetos 3D con par ches NURBS (B­Splines Racionales No Unifor mes), los cuales son optimizados mediante una Estr ategia Evolutiva Abstract—This article presents a method to fit 3D objects with patches NURBS (Non Un iform Rational B­Splines), which ar e optimized by means of Evolutionary Strategies (ES), which they determine the weights of th...

This paper proposes an off-line feedrate scheduling method of CNC machines constrained by chord tolerance, acceleration and jerk limitations. The off-line process for curve scanning and feedrate scheduling is realized as a pre-processor, which releases the computational burden in real-time task. The proposed method first scans a non-uniform rational B-spline (NURBS) curve and finds out the cruc...