Very interesting stuff, thanks for sharing! Local ambient occlusion has always been one of the things which was missing from PolyVox and I know other people have wanted it.
Have you seen any of the previous threads on this topic? I think the most useful was this one:
http://www.volumesoffun.com/phpBB3/viewtopic.php?f=14&t=481But I guess you may have seen it as you talk about quad-flipping. I also have some thoughts on how I was planning to approach the problem if I ever got around to it myself:
https://bitbucket.org/volumesoffun/polyvox/issues/26/consider-adding-very-local-ambientIt might sound like overkill but I was keen to see what else could be done with the neighbourhood information.
Thanks for the patch as well - I'm sure people will find it useful but I must say I probably won't integrate it myself, mostly because PolyVox is largely in maintenance mode at the moment.