spawn_by = "default:water",
-- Node (or list of nodes) that the decoration only spawns next to.
- -- Checks two horizontal planes of 8 neighbouring nodes (including
- -- diagonal neighbours), one plane level with the 'place_on' node and a
- -- plane one node above that.
+ -- Checks the 8 neighbouring nodes on the same Y, and also the ones
+ -- at Y+1, excluding both center nodes.
num_spawn_by = 1,
-- Number of spawn_by nodes that must be surrounding the decoration