core.register_on_generated(function(minp, maxp)
	if minp.y > 0 then return end
	local vm, emin, emax = core.get_mapgen_object("voxelmanip")
	local data = vm:get_data()
	for index in VoxelArea:new{MinEdge=emin, MaxEdge=emax}:iter(minp.x, minp.y, minp.z, maxp.x, maxp.y, maxp.z) do
		data[index] = core.get_content_id("default:stone")
	end
	vm:set_data(data)
	vm:set_lighting({day=5, night=5})
	vm:calc_lighting()
	vm:write_to_map(data)
end)
core.register_on_newplayer(function(player) player:setpos({x=0,y=50,z=0}) end)