Question about weight calculation and paper equation

[manurare]

Hello,

Thanks so much for sharing this wonderful implementation!

I have a question trying to understand the code. Here you calculate the alignment weights for the kernel. I understand your code. However it is not clear to me that it is the same as what is written in the paper in Eq. 3

In the paper, they estimate the normal of the projective plane for the south/north pole and they use that normal to compute the angle. However the normal you calculate is between the two vector differences between central vertex and neighbour 1 and 6. Is your method and the one in the paper equivalent? Do you really know what the projective plane of the north-south pole really means?