Journal of Zhejiang University-SCIENCE A

, Volume 10, Issue 4, pp 570–576 | Cite as

NURBS curve blending using extension

  • Yong-jin LiuEmail author
  • Rong-qi Qiu
  • Xiao-hui Liang


Curve and surface blending is an important operation in CAD systems, in which a non-uniform rational B-spline (NURBS) has been used as the de facto standard. In local corner blending, two curves intersecting at that corner are first made disjoint, and then the third blending curve is added-in to smoothly join the two curves with G1-or G2-continuity. In this paper we present a study to solve the joint problem based on curve extension. The following nice properties of this extension algorithm are exploited in depth: (1) The parameterization of the original shapes does not change; (2) No additional fragments are created. Various examples are presented to demonstrate that our solution is simple and efficient.

Key words

Curve blending Curve fairing Curve extension Non-uniform rational B-spline (NURBS) 

CLC number



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Copyright information

© Zhejiang University and Springer-Verlag GmbH 2009

Authors and Affiliations

  1. 1.Tsinghua National Lab for Information Science and TechnologyTsinghua UniversityBeijingChina
  2. 2.State Key Lab of Virtual Reality Technology and SystemsBeihang UniversityBeijingChina

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