(∫[0:1]x

P = (3/2)∫(x/|x|)∙da where da is the vector area of an element of the surface and x is the vector from X to the area centroid.

The potential is 3/2 times what it would be if the same total mass were concentrated all at the centroid of the facet.

Some dot products will be negative. Still (∫x∙da)/3 is the volume of the blob and ∫da = 0. da is the vector normal to the facet whose length is proportional to the area. We also compute moments 0, 1 and 2 of the blob, m0, m1 & m2.

(2017 Feb 1)

Moving the vertices around is like herding cats. They find too many interesting directions to go. There are just now two problems to solve:

- Keep the triangles nearly the same size.
- Avoid negative volumes—points with negative winding numbers.