MbJoinSurface Joint Surface
Class MbJoinSurface is declared in the surf_joint_surface.h file.
The join surface MbJoinSurface is defined by the set of curves RPArray< MbCurve3D > curves, the knot vector knots, the spline order degree, the boundary values of the first surface parameter umin and umax, the flag of the first surface parameter periodicity closedU, the flag of the second surface parameter periodicity closedV, the flag that indicates the presence of the surface pole at the boundary values of the first parameter isPoleUmin, isPoleUmax, the flag that indicates the presence of the surface pole at the boundary values of the second parameter isPoleUmin, isPoleUmax.
The curves curves are coordinated with each other: they have the same direction and the same parameter domain. The first surface parameter u coincides with the parameter of the curves, which is common for them. The first surface parameter takes values on the segment umin ≤ u ≤ umax, which corresponds to the domain of the curves. The surface can be periodic in the first parameter if all curves are periodic. Let the knot vector knots contain knotsCount elements, and the number of curves in the curves set be equal to curvesCount. The numbers of elements in the sets are related by the equality curvesCount + degree = knotsCount.
The second surface parameter v takes values on the segment vmin ≤ v ≤ vmax, where vmin = knots[degree − 1], vmax = knots[knotsCount − degree]. The surface cannot be periodic in the second parameter.
In the PointOn( double u, double v, MbCartPoint3D & s ) method, the radius vector of the surface s is described by the vector function
where \(N_j^{degree}(v)\) are B-splines of order degree for the j-th curve curves[j]. The join surface is shown in the figure:
Each curve s(const, v) with a fixed first surface parameter u = const is a NURBS curve of order degree constructed by the points curves[i](const).