Hello,
I am sharing my personal utility class that contains a lot of functions that help to compute some geometrical data on meshes, selections, mesh editing, splines, normals, polygons and more :
https://code.vonc.fr/utils
It's still in construction, there is more to come, the descriptions are not yet translated in english, there is not yet images for all, it's not all in Python 3 yet too, but I am working on it. 🙂
I am also making a C4D file that contains all theses functions, like a bit unit test file where you can play with each function.
I am searching a way to make a better presentation of it because it make a quite huge page actually, I'd like to have your opinion on it.
Here is also a specific chapter on bezier curves in a more tutorial way to understand them :
https://code.vonc.fr/courbe-de-bezier
And if you are interested, there is more stuff on my website, not necessary C4D but still 3D oriented.
I think will post here when I will translate some bach of them, with images.
I hope this stuff can help some !