Cave collision?

a while ago i created a thread about the navmesh for the normal map but right now i am having some problems finding the cave collision.
is this one also in one of the .nvm files? or is it one of those ainavdata cause the name sounds more like some navigation data for the mobs.
is the info about this stuff publicly available or does it need to be reversed?

Well it should be similar logic to use cave navmesh, but the files are in a completly different format and from what i know, no one has reversed them