Smooth/Interpolate 3D Curve (Skeleton axis)

I am trying to achieve a smooth curve representing the skeleton of a 3D-Model (STL-File).

By using a skeleton algorithm (among others) I managed to create the spline seen in the picture (red).

Now I am trying to get a smooth curve from the points of this spline (e.g. like the blue one) but I don't have an idea how nor can I find any 3D-capable functions which suit my needs. I especially need to get rid of these direction changes (marked black).

Any help is appreciated!

Answer 1

[darova]

see this question: LINK