I'm trying to interpolate a degree 3 periodic B-spline given 4 points on the curve. The points define the extremities of the roughly circular curve, and the resulting bspline should be symmetric in the vertical central line connecting the top and bottom points , i.e. the XZ plane.
I can achieve the desired shape in Rhino using a 'periodic uniform knot spacing' interpolation, however I can't find how to set this interpolation strategy in OCC and the result is skewed/assymetric (see attached images). I also cannot find how to interpolate a spline to have uniform multiplicity i.e. no repeating knots such that control points are not the start/end points of curve.
Can anyone please advise how I can achieve the desired b-spline interpolation from OpenCascade?