| | An algorithm to determine isoparametric curves along which a BSpline surface should be split in order to obtain patches of the same continuity. The continuity order is given at the construction time. It is possible to compute the surface patches corresponding to the splitting with the method of package SplitBSplineSurface. For a B-spline surface the discontinuities are localised at the knot values. Between two knots values the B-spline is infinitely continuously differentiable. For each parametric direction at a knot of range index the continuity in this direction is equal to : Degree - Mult (Index) where Degree is the degree of the basis B-spline functions and Mult the multiplicity of the knot of range Index in the given direction. If for your computation you need to have B-spline surface with a minima of continuity it can be interesting to know between which knot values, a B-spline patch, has a continuity of given order. This algorithm computes the indexes of the knots where you should split the surface, to obtain patches with a constant continuity given at the construction time. If you just want to compute the local derivatives on the surface you don't need to create the BSpline patches, you can use the functions LocalD1, LocalD2, LocalD3, LocalDN of the class BSplineSurface from package Geom. More...
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