This mod adds ash when fire burns something.
Every flammable node without on_burn will be overridden to make ash on burn.
If you want your node to make more ash, call in its on_burn ash.burn_node(pos, param2) a higher param2.
If you have a node that should be transformed to another node when ash is lying on it, do ash.nodes_with_ash["your:node"] = "convert:to" and ash.nodes_with_ash[#ash.nodes_with_ash] = "your:node".
You can also call ash.ash_onto_node(pos) if you want your node to be transformed directly. Note: pos is the position of the ash.
Look into license.txt.
