Cave update

I've been working on the cave in the slow pace I can nowadays. I've made some new cave shots of the new quadratic cave walls and the nice cave entrance contributed by theotherhiveking. The cave will get some settable multilevel architecture and longer settable entrance gorge later. FPS is a bit low on the shots, but since then I've been trying to optimize it, mostly it is around 20-40 FPS on the 6200Go, with a nice VIEW_DISTANCE, so don't get shocked by the 20- FPS! ( Well, it's enough if I am the only one shocked by it! :-) )