Created by: elfnor
The Centres Polygon node can produce the wrong matrix in some cases. These tend to be for faces whose normal is aligned with an axis.
See the image in the comment on my blog http://elfnor.com/simple-sverchok-01-centers-polygons.html#comment-2371038204
I've rewritten the polygons_centers.py to simplify it and fix this problem
elfnor