The construction of B-spline curves with shape control parameters is one of the most popular areas in computer aided geometric design. A class of new polynomial basis functions with two local shape parameters λ
i
μ
i
is presented to construct B-spline curves with multiple local shape control parameters
which is an extension of the classical cubic uniform B-spline basis functions. The properties of the proposed basis functions are analyzed and the corresponding piecewise polynomial curve with two local shape control parameters λ
i
μ
i
is constructed. The extension not only inherits the outstanding properties of the cubic uniform B-spline curves
but also has a good performance on adjusting their
local shapes by changing the two local shape control parameters. In particular
the G
1
continuous and the shapes of other segments on the curve can remain unchanged during manipulating the shape of one segment on the curve. Eventually
some applications in curve design are discussed and an extended application in surface design is also presented. The modeling examples illustrate that the new extension provides a valuable way for the design of curves and surfaces.
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references
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