Johannes,

I think I found a mistake in GeodesicGrid which caused many invalid memory read and also descresed perfomances:
in GeodesicGrid::visitTriangles() line 270, I think this:
    if (lev <= max_visit_level)
should be replaced by this:
    if (lev < max_visit_level)

otherwise the code iterates one level too far.

Could you confirm?

Fabien