Ugh, I wish I could read it but as I'm working in this space professionally reading GPLv3 code is... risky.
Been working in 2D with bezier implementation for our in-house CAD kernel. 3D parametric is limited at the moment, though.
Just because I’m curious, why the issue with reading GPL code? My understanding is that you would have to essentially directly copy and paste the code for the GPL license to apply to it.