In this paper we propose a new kind of nonlinear and geometry driven subdivision scheme for curve interpolation. Instead of using linear combination of old vertexes, displacement vector for every new vertex is given by normal vectors at old vertexes. The normal vectors are computed adaptively for each time of subdivision, and the limit curve is G1 smooth with wide ranges of free parameters. Wit...

We estimate error bounds between binary subdivision curves/surfaces and their control polygons after k-fold subdivision in terms of the maximal differences of the initial control point sequences and constants that depend on the subdivision mask. The bound is independent of the process of subdivision and can be evaluated without recursive subdivision. Our technique is independent of parameteriza...

Both the four-point and the uniform cubic B-spline refinement (i.e. subdivision) schemes double the number of vertices of a closed-loop polygonal curve P and respectively produce sequences of vertices fk and bk. The Js refinement proposed here produces vertices vk=(1–s)fk+sbk. Iterative applications of Js yield a family of curves parameterized by s. It includes the four-point curve (J0), the un...

Recent research has produced results on subdivision in arbitrary manifolds. These results can be applied to the manifold of lines and thus we can create subdivision schemes especially for ruled surfaces. We present different methods for refining discrete models of ruled surfaces: An algorithm combining subdivision and projection to the manifold of lines in Euclidean three-space. A further algor...

Although curves can be generally described by using concepts such as NURBS, we will introduce subdivision curves as a lead-in to the more general concept of subdivision surfaces. Suppose we wanted to perform knot-insertion in the middle of a B-spline curve defined by four control points, p0 through p3. Using the blossoming technique, we would determine the control point to be as in Figure 1. Th...

Abstract The aim of this paper is to investigate curve or surface design and modeling with geometric constraint by subdivision scheme. To construct a curve with a given length, constraint is employed on the free parameter of a newly proposed 4-point approximating subdivision scheme. Feasibility to this problem is investigated, convergence and smoothness analysis are presented, and more properti...

Properties of a parametric curve in R 3 are often determined by analysis of its piecewise linear (PL) approximation. For Bézier curves, there are standard algorithms, known as subdivision, that recursively create PL curves that converge to the curve in distance. The exterior angles of PL curves under subdivision are shown to converge to 0 at the rate of O(1 2 i), where i is the number of subdiv...

Subdivision schemes are iterative procedures to construct curves and constitute fundamental tools in Computer Aided Design. Starting with an initial control polygon, a subdivision scheme refines the computed values at the previous step according to some basic rules. The scheme is said to be convergent if there exists a limit curve. The computed values define a control polygon in each step. This...

These course notes will attempt to answer the following questions: What is subdivision? How can the rules for subdivision schemes be derived in a systematic manner? How can these rules be extended to handle special topological features such as extraordinary points or creases? We will argue that most subdivision schemes correspond to a special type of multigrid method that generates shapes which...

The promise of modeling by subdivision is to have simple rules that avoid cumbersome stitching-together of pieces. However, already in one variable, exactly reproducing a variety of basic shapes, such as conics and spirals, leads to non-stationary rules that are no longer as simple; and combining these pieces within the same curve by one set of rules is challenging. Moreover, basis functions, t...