This is a short note, elaborating on Feng et al. [1], which proposed B-spline free-form deformation (FFD) of polygonal objects using the generalized de Casteljau algorithm. The new method employs polynomial interpolation instead of the de Casteljau algorithm to accelerate computation.

Section two focuses on the computational cost of the de Casteljau algorithm and derives an explicit formula for the cost of evaluating the control points of a Bézier patch involved in FFD. An alternative method is presented in section three based on polynomial interpolation. The corresponding cost is also calculated and is minimized using the idea of precomputed matrices. Section four presents examples and numerical results confirming the authors’ claim: that the new method’s computation time is much smaller than that of the original method.

Although the authors’ claim is reasonable, the reader cannot confirm it because the paper is not self-contained. No description/definition of B-spline FFD is offered here, and neither is an explanation of its relation with Bézier curves and surfaces. Finally, the authors’ comments in section 4 seem to imply that the new method is not as accurate as the original one. I think that both methods are accurate, as is also indicated by the title of this paper.