Research on the Key Issues of Numerical Controlled Machine Layout Design
2014 ◽
Vol 548-549
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pp. 968-973
Keyword(s):
B Spline
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Formulas for the derivatives and normal vectors of non-rational B-spline and NURBS are proved based on de BOOR’s recursive formula. Compared with the existing approaches targeting at the non-rational B-spline basis functions, these equations are directly targeted at the controlling points, so the algorithms and programs for NURBS curve and surface can also be applied to the derivatives and normals, the calculating performance is increased. A simplified equation is also proved in this paper.