Juan Ignacio Polanco

For completeness I ran your `test1` function and I got: ```julia julia> test1() ERROR: MethodError: no method matching vtk_grid(::String, ::Vector{SVector{3, Float64}}, ::Vector{Any}) Closest candidates are: vtk_grid(::AbstractString, ::AbstractVector{T}, ::AbstractVector{T}, ::AbstractVector{T}; kwargs...)...

Hi @Kevin-Mattheus-Moerman, as you suggest, this is something which should be allowed by the `Periodic` boundary conditions [(docs here)](https://jipolanco.github.io/BSplineKit.jl/dev/interpolation/#BSplineKit.SplineInterpolations.interpolate). However, I just realised that interpolation of parametric curves (using `SVector`s...

This should be fixed in the upcoming 0.17.5 version (for cubic splines only). Let me know if it works for you. I'm reopening this issue since orders other than cubic...

It's available in the latest release, you should be able to try it out now. Let me know if you have any issues. > Can the `natural` option be combined...

> I've noticed the need to `copy(points)` above in your example. That wasn't needed for the Natural constraint. Is that intentional? Would be nice to avoid the need to copy...

Linear splines should be fixed in the upcoming v0.17.6.

> Did you perhaps only implement the smoothing for 1D interpolation? Oops, thanks for reporting this. That's right, I didn't think about parametric splines. This is easy to fix, I'll...

> I also have a separate question on the smoothing for these periodic functions. I tried to set λ rather high e.g. λ = 20 . The hope was that...