#Mod developer’s documentation for the Pedology mod for Minetest ##Nodes ###Ground nodes The ground nodes are the most basic nodes in this mod. They mainly differ in density. Except coarse sand, all ground nodes can be wet between a wetness level between 0 (dry) and 5 (slurry). Each ground type has a maximum wetness level. It is intended for later versions to reserve wetness levels 4 and 5 for mud (high-viscosity liquids), whereas levels 0-3 are used for solid blocks.

Here is the list of ground blocks with the maximum wetness level:

• clay: 5
• fine silt: 5
• medium silt: 4
• coarse silt: 3
• fine sand: 2
• medium sand: 1
• coarse sand: 0
• fine gravel: 1
• medium gravel: 2
• coarse gravel: 2

Currently, sand and gravel are not affected by gravity.

###Air and vacuum As an experimental feature, Pedology adds two new air node type and a vacuum node type:

• thin air
• very thin air
• vacuum

All three behave like the ordinary air. The vacuum is special as it removes 4 hearts per seconds for any lifeform which is inside it. The other node types have no special properties.

It has yet to be decided wheather these nodes are kept.

###Liquids Yes, there are some water and lava nodes, but are currently experimental.

##Itemstrings

###Ground nodes The itemstrings of all ground nodes follow this pattern:

pedology:<type>_<wetness>

where “<type>” is replaced with the ground type and “wetness” with the wetness level

####Types

• clay: clay
• fine silt: silt_fine
• medium silt: silt_medium
• coarse silt: silt_coarse
• fine sand: sand_fine
• medium sand: sand_medium
• coarse sand: sand_coarse
• fine gravel: gravel_fine
• medium gravel: gravel_medium
• coarse gravel: gravel_coarse

####Example The itemstring for “dry clay” is “pedology:clay_0”

###Air

• thin air: pedology:air_thinair1
• very thin air: pedology:air_thinair2
• vacuum: pedology:vacuum

##Groups ###Used groups The mod uses the following existing groups:

• water: A value of 1 means the node is water. This group is used to wetten sucky nodes.
• not_in_creative_inventory: For value of 1: This node type should not be added into creative inventories. This group is used by the creative mod of minetest_game, for example.
• crumbly: Used for compatibility with minetest_game. Usage may change in the future.
• sand: 1 means the node is sand. Used for compatiblity with minetest_game. Usage may change in the future.
• flammable: Used by turf (value: 1), indicates the nodes are flammable. Value can range from 1-3, 1 being the slowest.

###New groups The mod introduces the following groups:

• wet: Wetness level. Currently, the wetness level ranges from 0 to 5. The wetness descriptions are:
• 0: dry (solid) (node is not member of the wet group)
• 1: wet (solid)
• 2: watery (solid)
• 3: sludgy (solid)
• 4: muddy (now solid, liquid in later versions)
• 5: slurry (now solid, liquid in later versions)
• sucky: Suckyness. Declares a node to “suck” wetness from water and oozing nodes. Any non-zero value makes the node a “sucky” node
• oozing: Oozing level. Members of this group can transfer their wetness to sucky nodes. Any non-zero value makes the node an “oozing” node. Maybe different oozing levels will be used in future. Nodes should be only added to this group if they are also wet.
• melting_point: the minimal temperature at which the node becomes destroyed. This depends on the hotness of neighbor nodes. Planned for later versions.
• hot: The temperature of the node. Not used yet, but intended for lava, therefore planned for late versions.
• sun_dry: If 1, the node may dry off over time when it is in direct sun light

##Functions ###pedology.dry(pos) Reduces the wetness level of the node at pos by 1, if possible. This is done by replacing the node with a “drier” version of it, if available. ####Parameters

• pos: Position of node, specified as a table of the format { x = x, y = y, z = z}

####Return value nil

###pedology.wetten(pos) Increases the wetness level of the node at pos by 1, if possible. This is done by replacing the node with a “wetter” version of it, if available. ####Parameters

• pos: Position of node, specified as a table of the format { x = x, y = y, z = z} ####Return value nil

###pedology.register_sucky_group(basename, basedescription, maxwet, oozeinterval, oozechance, melttable, sounds, additional_groups) Registers a bunch of suckyandoozingnodes to Pedology . This function assumes that textures are ready for the node, one texture for eachwetness level (up to maxwet). They have to be named according to the pattern pedology__.pngand must reside in thetexturesfolder. Example name:pedology_clay_0.pngis the texture for dry clay,pedology_clay_1.png` is texture for wet clay, and so on. ####Parameters

• basename: A part of the internal itemstring of all the nodes to be registered. The full itemstring for a node would be “pedology:<basename>_<wetness>, where “<basename>” is replaced with the given basename and “<wetness>” is replaced with the wetness level (a single digit). This parameter is also used to find the textures.
• basedescription: A part of the user-visible description for each node. The full description is built from the template “<wetnessstring> <basedescription>. <wetnessstring> would be “dry”, “wet”, “watery”, “sludgy”, “muddy” or “slurry”.
• maxwet: The maximum wetness level of the nodes. Must be at least 0 and at most 5.
• oozeinterval: The interval in seconds in which the node may ooze its wetness to other nodes (Minimum: 1)
• oozechance: The interted chance (1/oozechance) to ooze each time the oozeinterval has passed.
• melttable: Table of melting_point values for each wetness level. The table length must equal maxwet+1. This parameter may alternatively be nil (all nodes are indestructible by heat then). Note that lava and melting points are not implemented yet.
• sounds: Sound specification for every node (Definition is the same as for minetest.register_node).
• additional_groups: Table of additional groups for every node. May also be empty or nil, meaning no additional groups will be added.

####Return value nil