Infinitely deep or not?
The engine is very dependant on knowing the highest block on each column, mostly for lighting. Trying to come up with some generic way of keeping track on that in an infinite level is interesting to say the least. It looks like i have to keep track of columns of chunks no matter what i do, and that also means that fixed depth columns would be much cleaner and easier to code. 1000 tiles deep, perhaps.
I will continue butting my head against this a while longer. Figuring this out is difficult and fun!
