The B-spline basis function is given by one recursive formula. However,I hope to obtain popular expression: a0x^n + a1x^(n-1) + ... + an. From the answer How to build a recursive spline function in C++, it seems that Piegl's algorithm can do that. Can anyone give more information about the algorithm?
1 Answer
If you do not have access to the NURBS book by Piegl, then you might look at An Introduction to Polar Forms by Hans-Peter Seidel on pp 38-46 of the 1993 IEEE Computer Graphics & Applications. He diagrams the B-spline computations for the polar form, from which the polynomial coefficient form is a routine conversion.
Let me offer one more reference to an excellent expositor, Phillip J. Schneider, in his paragraph on defining the basis functions. Www.mactech.com/articles/develop/issue_25/schneider.html
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$\begingroup$ I have NURBS book by Piegl. But I only find the routine to calculate one point on the B-spline curve using recursive formula. $\endgroup$ Nov 7, 2014 at 2:51
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$\begingroup$ Is it necessary to convert B-spline curve from recursive form to power basis form? I am to geometric modeling, so I am familiar with the power basis form. Which form does geometric modeling software prefer? $\endgroup$ Nov 12, 2014 at 5:23