meshing: Some triangles have the opposite winding from what they should have

[waywardmonkeys]

When we mesh a sphere and render it, we get some roughness and issues that look like some triangles are facing the wrong way.

This is a placeholder issue until I can add more detail (unless you already have an idea of what this might be).

[mkeeter]

This may or may not be a bug – the mesh should always be topologically manifold and watertight, but may have self-intersections if vertices escape their octree cells (which they can do to hit sharp features).

On the other hand, a sphere is simple enough that vertices shouldn't escape their cells, so there could be an issue with the QEF solver or normal sampling.