uwestoehr wrote: ↑Sat Jun 05, 2021 4:06 pm
For developers the section https://wiki.freecadweb.org/B-Splines#Limitations
might be interesting. I know that ironing out the limitations is not easy, but maybe there are some libraries around that actually provide e.g. the calculation of a tangential to a spline.
The problem are not static calculations. In fact, the solver, unlike for any other geometry, relies on OCCT for calculation of the B-Spline. The solver only sees points (control points, i.e. poles). That is the problem. What is needed is to implement in the solver the parametric calculation of the B-Spline along with all its partial derivatives, then implement the constraints (such as point on object) where they need to be geometry specific. DeepSOIC has given it a thought
Thanks. You reminded me that I need to come up with an n-th derivative algorithm for b-spline, with parameter derivative support. That's like d2x(t)/(dt dp), d3x(t)/(dt2dp), and so on...
He also posted another post where he asked help for a discussion, which he did not get (and which I cannot find...)
Personally, I have not found time to undertake this yet.