Minetest Lua Modding API Reference
==================================
* More information at
* Developer Wiki:
* (Unofficial) Minetest Modding Book by rubenwardy:
Introduction
------------
Content and functionality can be added to Minetest using Lua scripting
in run-time loaded mods.
A mod is a self-contained bunch of scripts, textures and other related
things, which is loaded by and interfaces with Minetest.
Mods are contained and ran solely on the server side. Definitions and media
files are automatically transferred to the client.
If you see a deficiency in the API, feel free to attempt to add the
functionality in the engine and API, and to document it here.
Programming in Lua
------------------
If you have any difficulty in understanding this, please read
[Programming in Lua](http://www.lua.org/pil/).
Startup
-------
Mods are loaded during server startup from the mod load paths by running
the `init.lua` scripts in a shared environment.
Paths
-----
* `RUN_IN_PLACE=1` (Windows release, local build)
* `$path_user`: ``
* `$path_share`: ``
* `RUN_IN_PLACE=0`: (Linux release)
* `$path_share`:
* Linux: `/usr/share/minetest`
* Windows: `/minetest-0.4.x`
* `$path_user`:
* Linux: `$HOME/.minetest`
* Windows: `C:/users//AppData/minetest` (maybe)
Games
=====
Games are looked up from:
* `$path_share/games//`
* `$path_user/games//`
Where `` is unique to each game.
The game directory can contain the following files:
* `game.conf`, with the following keys:
* `name`: Required, a human readable title to address the game, e.g. `name = Minetest`.
* `description`: Short description to be shown in the content tab
* `allowed_mapgens = `
e.g. `allowed_mapgens = v5,v6,flat`
Mapgens not in this list are removed from the list of mapgens for the
game.
If not specified, all mapgens are allowed.
* `disallowed_mapgens = `
e.g. `disallowed_mapgens = v5,v6,flat`
These mapgens are removed from the list of mapgens for the game.
When both `allowed_mapgens` and `disallowed_mapgens` are
specified, `allowed_mapgens` is applied before
`disallowed_mapgens`.
* `disallowed_mapgen_settings= `
e.g. `disallowed_mapgen_settings = mgv5_spflags`
These settings are hidden for this game in the world creation
dialog and game start menu.
* `author`: The author of the game. It only appears when downloaded from
ContentDB.
* `release`: Ignore this: Should only ever be set by ContentDB, as it is
an internal ID used to track versions.
* `minetest.conf`:
Used to set default settings when running this game.
* `settingtypes.txt`:
In the same format as the one in builtin.
This settingtypes.txt will be parsed by the menu and the settings will be
displayed in the "Games" category in the advanced settings tab.
* If the game contains a folder called `textures` the server will load it as a
texturepack, overriding mod textures.
Any server texturepack will override mod textures and the game texturepack.
Menu images
-----------
Games can provide custom main menu images. They are put inside a `menu`
directory inside the game directory.
The images are named `$identifier.png`, where `$identifier` is one of
`overlay`, `background`, `footer`, `header`.
If you want to specify multiple images for one identifier, add additional
images named like `$identifier.$n.png`, with an ascending number $n starting
with 1, and a random image will be chosen from the provided ones.
Mods
====
Mod load path
-------------
Paths are relative to the directories listed in the [Paths] section above.
* `games//mods/`
* `mods/`
* `worlds//worldmods/`
World-specific games
--------------------
It is possible to include a game in a world; in this case, no mods or
games are loaded or checked from anywhere else.
This is useful for e.g. adventure worlds and happens if the `/game/`
directory exists.
Mods should then be placed in `/game/mods/`.
Modpacks
--------
Mods can be put in a subdirectory, if the parent directory, which otherwise
should be a mod, contains a file named `modpack.conf`.
The file is a key-value store of modpack details.
* `name`: The modpack name. Allows Minetest to determine the modpack name even
if the folder is wrongly named.
* `description`: Description of mod to be shown in the Mods tab of the main
menu.
* `author`: The author of the modpack. It only appears when downloaded from
ContentDB.
* `release`: Ignore this: Should only ever be set by ContentDB, as it is an
internal ID used to track versions.
* `title`: A human-readable title to address the modpack.
Note: to support 0.4.x, please also create an empty modpack.txt file.
Mod directory structure
-----------------------
mods
├── modname
│ ├── mod.conf
│ ├── screenshot.png
│ ├── settingtypes.txt
│ ├── init.lua
│ ├── models
│ ├── textures
│ │ ├── modname_stuff.png
│ │ ├── modname_stuff_normal.png
│ │ ├── modname_something_else.png
│ │ ├── subfolder_foo
│ │ │ ├── modname_more_stuff.png
│ │ │ └── another_subfolder
│ │ └── bar_subfolder
│ ├── sounds
│ ├── media
│ ├── locale
│ └──
└── another
### modname
The location of this directory can be fetched by using
`minetest.get_modpath(modname)`.
### mod.conf
A `Settings` file that provides meta information about the mod.
* `name`: The mod name. Allows Minetest to determine the mod name even if the
folder is wrongly named.
* `description`: Description of mod to be shown in the Mods tab of the main
menu.
* `depends`: A comma separated list of dependencies. These are mods that must be
loaded before this mod.
* `optional_depends`: A comma separated list of optional dependencies.
Like a dependency, but no error if the mod doesn't exist.
* `author`: The author of the mod. It only appears when downloaded from
ContentDB.
* `release`: Ignore this: Should only ever be set by ContentDB, as it is an
internal ID used to track versions.
* `title`: A human-readable title to address the mod.
Note: to support 0.4.x, please also provide depends.txt.
### `screenshot.png`
A screenshot shown in the mod manager within the main menu. It should
have an aspect ratio of 3:2 and a minimum size of 300×200 pixels.
### `depends.txt`
**Deprecated:** you should use mod.conf instead.
This file is used if there are no dependencies in mod.conf.
List of mods that have to be loaded before loading this mod.
A single line contains a single modname.
Optional dependencies can be defined by appending a question mark
to a single modname. This means that if the specified mod
is missing, it does not prevent this mod from being loaded.
### `description.txt`
**Deprecated:** you should use mod.conf instead.
This file is used if there is no description in mod.conf.
A file containing a description to be shown in the Mods tab of the main menu.
### `settingtypes.txt`
The format is documented in `builtin/settingtypes.txt`.
It is parsed by the main menu settings dialogue to list mod-specific
settings in the "Mods" category.
### `init.lua`
The main Lua script. Running this script should register everything it
wants to register. Subsequent execution depends on minetest calling the
registered callbacks.
`minetest.settings` can be used to read custom or existing settings at load
time, if necessary. (See [`Settings`])
### `textures`, `sounds`, `media`, `models`, `locale`
Media files (textures, sounds, whatever) that will be transferred to the
client and will be available for use by the mod and translation files for
the clients (see [Translations]).
It is suggested to use the folders for the purpous they are thought for,
eg. put textures into `textures`, translation files into `locale`,
models for entities or meshnodes into `models` et cetera.
These folders and subfolders can contain subfolders.
Subfolders with names starting with `_` or `.` are ignored.
If a subfolder contains a media file with the same name as a media file
in one of its parents, the parent's file is used.
Although it is discouraged, a mod can overwrite a media file of any mod that it
depends on by supplying a file with an equal name.
Naming conventions
------------------
Registered names should generally be in this format:
modname:
`` can have these characters:
a-zA-Z0-9_
This is to prevent conflicting names from corrupting maps and is
enforced by the mod loader.
Registered names can be overridden by prefixing the name with `:`. This can
be used for overriding the registrations of some other mod.
The `:` prefix can also be used for maintaining backwards compatibility.
### Example
In the mod `experimental`, there is the ideal item/node/entity name `tnt`.
So the name should be `experimental:tnt`.
Any mod can redefine `experimental:tnt` by using the name
:experimental:tnt
when registering it. That mod is required to have `experimental` as a
dependency.
Aliases
=======
Aliases of itemnames can be added by using
`minetest.register_alias(alias, original_name)` or
`minetest.register_alias_force(alias, original_name)`.
This adds an alias `alias` for the item called `original_name`.
From now on, you can use `alias` to refer to the item `original_name`.
The only difference between `minetest.register_alias` and
`minetest.register_alias_force` is that if an item named `alias` already exists,
`minetest.register_alias` will do nothing while
`minetest.register_alias_force` will unregister it.
This can be used for maintaining backwards compatibility.
This can also set quick access names for things, e.g. if
you have an item called `epiclylongmodname:stuff`, you could do
minetest.register_alias("stuff", "epiclylongmodname:stuff")
and be able to use `/giveme stuff`.
Mapgen aliases
--------------
In a game, a certain number of these must be set to tell core mapgens which
of the game's nodes are to be used for core mapgen generation. For example:
minetest.register_alias("mapgen_stone", "default:stone")
### Aliases for non-V6 mapgens
#### Essential aliases
* mapgen_stone
* mapgen_water_source
* mapgen_river_water_source
`mapgen_river_water_source` is required for mapgens with sloping rivers where
it is necessary to have a river liquid node with a short `liquid_range` and
`liquid_renewable = false` to avoid flooding.
#### Optional aliases
* mapgen_lava_source
Fallback lava node used if cave liquids are not defined in biome definitions.
Deprecated for non-V6 mapgens, define cave liquids in biome definitions instead.
* mapgen_cobble
Fallback node used if dungeon nodes are not defined in biome definitions.
Deprecated for non-V6 mapgens, define dungeon nodes in biome definitions instead.
### Aliases needed for Mapgen V6
* mapgen_stone
* mapgen_water_source
* mapgen_lava_source
* mapgen_dirt
* mapgen_dirt_with_grass
* mapgen_sand
* mapgen_gravel
* mapgen_desert_stone
* mapgen_desert_sand
* mapgen_dirt_with_snow
* mapgen_snowblock
* mapgen_snow
* mapgen_ice
* mapgen_tree
* mapgen_leaves
* mapgen_apple
* mapgen_jungletree
* mapgen_jungleleaves
* mapgen_junglegrass
* mapgen_pine_tree
* mapgen_pine_needles
* mapgen_cobble
* mapgen_stair_cobble
* mapgen_mossycobble
* mapgen_stair_desert_stone
### Setting the node used in Mapgen Singlenode
By default the world is filled with air nodes. To set a different node use, for
example:
minetest.register_alias("mapgen_singlenode", "default:stone")
Textures
========
Mods should generally prefix their textures with `modname_`, e.g. given
the mod name `foomod`, a texture could be called:
foomod_foothing.png
Textures are referred to by their complete name, or alternatively by
stripping out the file extension:
* e.g. `foomod_foothing.png`
* e.g. `foomod_foothing`
Texture modifiers
-----------------
There are various texture modifiers that can be used
to let the client generate textures on-the-fly.
The modifiers are applied directly in sRGB colorspace,
i.e. without gamma-correction.
### Texture overlaying
Textures can be overlaid by putting a `^` between them.
Example:
default_dirt.png^default_grass_side.png
`default_grass_side.png` is overlaid over `default_dirt.png`.
The texture with the lower resolution will be automatically upscaled to
the higher resolution texture.
### Texture grouping
Textures can be grouped together by enclosing them in `(` and `)`.
Example: `cobble.png^(thing1.png^thing2.png)`
A texture for `thing1.png^thing2.png` is created and the resulting
texture is overlaid on top of `cobble.png`.
### Escaping
Modifiers that accept texture names (e.g. `[combine`) accept escaping to allow
passing complex texture names as arguments. Escaping is done with backslash and
is required for `^` and `:`.
Example: `cobble.png^[lowpart:50:color.png\^[mask\:trans.png`
The lower 50 percent of `color.png^[mask:trans.png` are overlaid
on top of `cobble.png`.
### Advanced texture modifiers
#### Crack
* `[crack::
`
* `[cracko::
`
* `[crack:::
`
* `[cracko:::
`
Parameters:
* ``: tile count (in each direction)
* ``: animation frame count
* `
`: current animation frame
Draw a step of the crack animation on the texture.
`crack` draws it normally, while `cracko` lays it over, keeping transparent
pixels intact.
Example:
default_cobble.png^[crack:10:1
#### `[combine:x:,=:,=:...`
* ``: width
* ``: height
* ``: x position
* ``: y position
* ``: texture to combine
Creates a texture of size `` times `` and blits the listed files to their
specified coordinates.
Example:
[combine:16x32:0,0=default_cobble.png:0,16=default_wood.png
#### `[resize:x`
Resizes the texture to the given dimensions.
Example:
default_sandstone.png^[resize:16x16
#### `[opacity:`
Makes the base image transparent according to the given ratio.
`r` must be between 0 (transparent) and 255 (opaque).
Example:
default_sandstone.png^[opacity:127
#### `[invert:`
Inverts the given channels of the base image.
Mode may contain the characters "r", "g", "b", "a".
Only the channels that are mentioned in the mode string will be inverted.
Example:
default_apple.png^[invert:rgb
#### `[brighten`
Brightens the texture.
Example:
tnt_tnt_side.png^[brighten
#### `[noalpha`
Makes the texture completely opaque.
Example:
default_leaves.png^[noalpha
#### `[makealpha:,,`
Convert one color to transparency.
Example:
default_cobble.png^[makealpha:128,128,128
#### `[transform`
* ``: transformation(s) to apply
Rotates and/or flips the image.
`` can be a number (between 0 and 7) or a transform name.
Rotations are counter-clockwise.
0 I identity
1 R90 rotate by 90 degrees
2 R180 rotate by 180 degrees
3 R270 rotate by 270 degrees
4 FX flip X
5 FXR90 flip X then rotate by 90 degrees
6 FY flip Y
7 FYR90 flip Y then rotate by 90 degrees
Example:
default_stone.png^[transformFXR90
#### `[inventorycube{{{`
Escaping does not apply here and `^` is replaced by `&` in texture names
instead.
Create an inventory cube texture using the side textures.
Example:
[inventorycube{grass.png{dirt.png&grass_side.png{dirt.png&grass_side.png
Creates an inventorycube with `grass.png`, `dirt.png^grass_side.png` and
`dirt.png^grass_side.png` textures
#### `[lowpart::`
Blit the lower ``% part of `` on the texture.
Example:
base.png^[lowpart:25:overlay.png
#### `[verticalframe::`
* ``: animation frame count
* ``: current animation frame
Crops the texture to a frame of a vertical animation.
Example:
default_torch_animated.png^[verticalframe:16:8
#### `[mask:`
Apply a mask to the base image.
The mask is applied using binary AND.
#### `[sheet:x:,`
Retrieves a tile at position x,y from the base image
which it assumes to be a tilesheet with dimensions w,h.
#### `[colorize::`
Colorize the textures with the given color.
`` is specified as a `ColorString`.
`` is an int ranging from 0 to 255 or the word "`alpha`". If
it is an int, then it specifies how far to interpolate between the
colors where 0 is only the texture color and 255 is only ``. If
omitted, the alpha of `` will be used as the ratio. If it is
the word "`alpha`", then each texture pixel will contain the RGB of
`` and the alpha of `` multiplied by the alpha of the
texture pixel.
#### `[multiply:`
Multiplies texture colors with the given color.
`` is specified as a `ColorString`.
Result is more like what you'd expect if you put a color on top of another
color, meaning white surfaces get a lot of your new color while black parts
don't change very much.
Hardware coloring
-----------------
The goal of hardware coloring is to simplify the creation of
colorful nodes. If your textures use the same pattern, and they only
differ in their color (like colored wool blocks), you can use hardware
coloring instead of creating and managing many texture files.
All of these methods use color multiplication (so a white-black texture
with red coloring will result in red-black color).
### Static coloring
This method is useful if you wish to create nodes/items with
the same texture, in different colors, each in a new node/item definition.
#### Global color
When you register an item or node, set its `color` field (which accepts a
`ColorSpec`) to the desired color.
An `ItemStack`'s static color can be overwritten by the `color` metadata
field. If you set that field to a `ColorString`, that color will be used.
#### Tile color
Each tile may have an individual static color, which overwrites every
other coloring method. To disable the coloring of a face,
set its color to white (because multiplying with white does nothing).
You can set the `color` property of the tiles in the node's definition
if the tile is in table format.
### Palettes
For nodes and items which can have many colors, a palette is more
suitable. A palette is a texture, which can contain up to 256 pixels.
Each pixel is one possible color for the node/item.
You can register one node/item, which can have up to 256 colors.
#### Palette indexing
When using palettes, you always provide a pixel index for the given
node or `ItemStack`. The palette is read from left to right and from
top to bottom. If the palette has less than 256 pixels, then it is
stretched to contain exactly 256 pixels (after arranging the pixels
to one line). The indexing starts from 0.
Examples:
* 16x16 palette, index = 0: the top left corner
* 16x16 palette, index = 4: the fifth pixel in the first row
* 16x16 palette, index = 16: the pixel below the top left corner
* 16x16 palette, index = 255: the bottom right corner
* 2 (width) x 4 (height) palette, index = 31: the top left corner.
The palette has 8 pixels, so each pixel is stretched to 32 pixels,
to ensure the total 256 pixels.
* 2x4 palette, index = 32: the top right corner
* 2x4 palette, index = 63: the top right corner
* 2x4 palette, index = 64: the pixel below the top left corner
#### Using palettes with items
When registering an item, set the item definition's `palette` field to
a texture. You can also use texture modifiers.
The `ItemStack`'s color depends on the `palette_index` field of the
stack's metadata. `palette_index` is an integer, which specifies the
index of the pixel to use.
#### Linking palettes with nodes
When registering a node, set the item definition's `palette` field to
a texture. You can also use texture modifiers.
The node's color depends on its `param2`, so you also must set an
appropriate `paramtype2`:
* `paramtype2 = "color"` for nodes which use their full `param2` for
palette indexing. These nodes can have 256 different colors.
The palette should contain 256 pixels.
* `paramtype2 = "colorwallmounted"` for nodes which use the first
five bits (most significant) of `param2` for palette indexing.
The remaining three bits are describing rotation, as in `wallmounted`
paramtype2. Division by 8 yields the palette index (without stretching the
palette). These nodes can have 32 different colors, and the palette
should contain 32 pixels.
Examples:
* `param2 = 17` is 2 * 8 + 1, so the rotation is 1 and the third (= 2 + 1)
pixel will be picked from the palette.
* `param2 = 35` is 4 * 8 + 3, so the rotation is 3 and the fifth (= 4 + 1)
pixel will be picked from the palette.
* `paramtype2 = "colorfacedir"` for nodes which use the first
three bits of `param2` for palette indexing. The remaining
five bits are describing rotation, as in `facedir` paramtype2.
Division by 32 yields the palette index (without stretching the
palette). These nodes can have 8 different colors, and the
palette should contain 8 pixels.
Examples:
* `param2 = 17` is 0 * 32 + 17, so the rotation is 17 and the
first (= 0 + 1) pixel will be picked from the palette.
* `param2 = 35` is 1 * 32 + 3, so the rotation is 3 and the
second (= 1 + 1) pixel will be picked from the palette.
To colorize a node on the map, set its `param2` value (according
to the node's paramtype2).
### Conversion between nodes in the inventory and on the map
Static coloring is the same for both cases, there is no need
for conversion.
If the `ItemStack`'s metadata contains the `color` field, it will be
lost on placement, because nodes on the map can only use palettes.
If the `ItemStack`'s metadata contains the `palette_index` field, it is
automatically transferred between node and item forms by the engine,
when a player digs or places a colored node.
You can disable this feature by setting the `drop` field of the node
to itself (without metadata).
To transfer the color to a special drop, you need a drop table.
Example:
minetest.register_node("mod:stone", {
description = "Stone",
tiles = {"default_stone.png"},
paramtype2 = "color",
palette = "palette.png",
drop = {
items = {
-- assume that mod:cobblestone also has the same palette
{items = {"mod:cobblestone"}, inherit_color = true },
}
}
})
### Colored items in craft recipes
Craft recipes only support item strings, but fortunately item strings
can also contain metadata. Example craft recipe registration:
minetest.register_craft({
output = minetest.itemstring_with_palette("wool:block", 3),
type = "shapeless",
recipe = {
"wool:block",
"dye:red",
},
})
To set the `color` field, you can use `minetest.itemstring_with_color`.
Metadata field filtering in the `recipe` field are not supported yet,
so the craft output is independent of the color of the ingredients.
Soft texture overlay
--------------------
Sometimes hardware coloring is not enough, because it affects the
whole tile. Soft texture overlays were added to Minetest to allow
the dynamic coloring of only specific parts of the node's texture.
For example a grass block may have colored grass, while keeping the
dirt brown.
These overlays are 'soft', because unlike texture modifiers, the layers
are not merged in the memory, but they are simply drawn on top of each
other. This allows different hardware coloring, but also means that
tiles with overlays are drawn slower. Using too much overlays might
cause FPS loss.
For inventory and wield images you can specify overlays which
hardware coloring does not modify. You have to set `inventory_overlay`
and `wield_overlay` fields to an image name.
To define a node overlay, simply set the `overlay_tiles` field of the node
definition. These tiles are defined in the same way as plain tiles:
they can have a texture name, color etc.
To skip one face, set that overlay tile to an empty string.
Example (colored grass block):
minetest.register_node("default:dirt_with_grass", {
description = "Dirt with Grass",
-- Regular tiles, as usual
-- The dirt tile disables palette coloring
tiles = {{name = "default_grass.png"},
{name = "default_dirt.png", color = "white"}},
-- Overlay tiles: define them in the same style
-- The top and bottom tile does not have overlay
overlay_tiles = {"", "",
{name = "default_grass_side.png"}},
-- Global color, used in inventory
color = "green",
-- Palette in the world
paramtype2 = "color",
palette = "default_foilage.png",
})
Sounds
======
Only Ogg Vorbis files are supported.
For positional playing of sounds, only single-channel (mono) files are
supported. Otherwise OpenAL will play them non-positionally.
Mods should generally prefix their sounds with `modname_`, e.g. given
the mod name "`foomod`", a sound could be called:
foomod_foosound.ogg
Sounds are referred to by their name with a dot, a single digit and the
file extension stripped out. When a sound is played, the actual sound file
is chosen randomly from the matching sounds.
When playing the sound `foomod_foosound`, the sound is chosen randomly
from the available ones of the following files:
* `foomod_foosound.ogg`
* `foomod_foosound.0.ogg`
* `foomod_foosound.1.ogg`
* (...)
* `foomod_foosound.9.ogg`
Examples of sound parameter tables:
-- Play locationless on all clients
{
gain = 1.0, -- default
fade = 0.0, -- default, change to a value > 0 to fade the sound in
pitch = 1.0, -- default
}
-- Play locationless to one player
{
to_player = name,
gain = 1.0, -- default
fade = 0.0, -- default, change to a value > 0 to fade the sound in
pitch = 1.0, -- default
}
-- Play locationless to one player, looped
{
to_player = name,
gain = 1.0, -- default
loop = true,
}
-- Play at a location
{
pos = {x = 1, y = 2, z = 3},
gain = 1.0, -- default
max_hear_distance = 32, -- default, uses an euclidean metric
}
-- Play connected to an object, looped
{
object = ,
gain = 1.0, -- default
max_hear_distance = 32, -- default, uses an euclidean metric
loop = true,
}
-- Play at a location, heard by anyone *but* the given player
{
pos = {x = 32, y = 0, z = 100},
max_hear_distance = 40,
exclude_player = name,
}
Looped sounds must either be connected to an object or played locationless to
one player using `to_player = name`.
A positional sound will only be heard by players that are within
`max_hear_distance` of the sound position, at the start of the sound.
`exclude_player = name` can be applied to locationless, positional and object-
bound sounds to exclude a single player from hearing them.
`SimpleSoundSpec`
-----------------
Specifies a sound name, gain (=volume) and pitch.
This is either a string or a table.
In string form, you just specify the sound name or
the empty string for no sound.
Table form has the following fields:
* `name`: Sound name
* `gain`: Volume (`1.0` = 100%)
* `pitch`: Pitch (`1.0` = 100%)
`gain` and `pitch` are optional and default to `1.0`.
Examples:
* `""`: No sound
* `{}`: No sound
* `"default_place_node"`: Play e.g. `default_place_node.ogg`
* `{name = "default_place_node"}`: Same as above
* `{name = "default_place_node", gain = 0.5}`: 50% volume
* `{name = "default_place_node", gain = 0.9, pitch = 1.1}`: 90% volume, 110% pitch
Special sound files
-------------------
These sound files are played back by the engine if provided.
* `player_damage`: Played when the local player takes damage (gain = 0.5)
* `player_falling_damage`: Played when the local player takes
damage by falling (gain = 0.5)
* `player_jump`: Played when the local player jumps
* `default_dig_`: Default node digging sound
(see node sound definition for details)
Registered definitions
======================
Anything added using certain [Registration functions] gets added to one or more
of the global [Registered definition tables].
Note that in some cases you will stumble upon things that are not contained
in these tables (e.g. when a mod has been removed). Always check for
existence before trying to access the fields.
Example:
All nodes register with `minetest.register_node` get added to the table
`minetest.registered_nodes`.
If you want to check the drawtype of a node, you could do:
local function get_nodedef_field(nodename, fieldname)
if not minetest.registered_nodes[nodename] then
return nil
end
return minetest.registered_nodes[nodename][fieldname]
end
local drawtype = get_nodedef_field(nodename, "drawtype")
Nodes
=====
Nodes are the bulk data of the world: cubes and other things that take the
space of a cube. Huge amounts of them are handled efficiently, but they
are quite static.
The definition of a node is stored and can be accessed by using
minetest.registered_nodes[node.name]
See [Registered definitions].
Nodes are passed by value between Lua and the engine.
They are represented by a table:
{name="name", param1=num, param2=num}
`param1` and `param2` are 8-bit integers ranging from 0 to 255. The engine uses
them for certain automated functions. If you don't use these functions, you can
use them to store arbitrary values.
Node paramtypes
---------------
The functions of `param1` and `param2` are determined by certain fields in the
node definition.
The function of `param1` is determined by `paramtype` in node definition.
`param1` is reserved for the engine when `paramtype != "none"`.
* `paramtype = "light"`
* The value stores light with and without sun in its upper and lower 4 bits
respectively.
* Required by a light source node to enable spreading its light.
* Required by the following drawtypes as they determine their visual
brightness from their internal light value:
* torchlike
* signlike
* firelike
* fencelike
* raillike
* nodebox
* mesh
* plantlike
* plantlike_rooted
* `paramtype = "none"`
* `param1` will not be used by the engine and can be used to store
an arbitrary value
The function of `param2` is determined by `paramtype2` in node definition.
`param2` is reserved for the engine when `paramtype2 != "none"`.
* `paramtype2 = "flowingliquid"`
* Used by `drawtype = "flowingliquid"` and `liquidtype = "flowing"`
* The liquid level and a flag of the liquid are stored in `param2`
* Bits 0-2: Liquid level (0-7). The higher, the more liquid is in this node;
see `minetest.get_node_level`, `minetest.set_node_level` and `minetest.add_node_level`
to access/manipulate the content of this field
* Bit 3: If set, liquid is flowing downwards (no graphical effect)
* `paramtype2 = "wallmounted"`
* Supported drawtypes: "torchlike", "signlike", "normal", "nodebox", "mesh"
* The rotation of the node is stored in `param2`
* You can make this value by using `minetest.dir_to_wallmounted()`
* Values range 0 - 5
* The value denotes at which direction the node is "mounted":
0 = y+, 1 = y-, 2 = x+, 3 = x-, 4 = z+, 5 = z-
* `paramtype2 = "facedir"`
* Supported drawtypes: "normal", "nodebox", "mesh"
* The rotation of the node is stored in `param2`. Furnaces and chests are
rotated this way. Can be made by using `minetest.dir_to_facedir()`.
* Values range 0 - 23
* facedir / 4 = axis direction:
0 = y+, 1 = z+, 2 = z-, 3 = x+, 4 = x-, 5 = y-
* facedir modulo 4 = rotation around that axis
* `paramtype2 = "leveled"`
* Only valid for "nodebox" with 'type = "leveled"', and "plantlike_rooted".
* Leveled nodebox:
* The level of the top face of the nodebox is stored in `param2`.
* The other faces are defined by 'fixed = {}' like 'type = "fixed"'
nodeboxes.
* The nodebox height is (`param2` / 64) nodes.
* The maximum accepted value of `param2` is 127.
* Rooted plantlike:
* The height of the 'plantlike' section is stored in `param2`.
* The height is (`param2` / 16) nodes.
* `paramtype2 = "degrotate"`
* Valid for `plantlike` and `mesh` drawtypes. The rotation of the node is
stored in `param2`.
* Values range 0–239. The value stored in `param2` is multiplied by 1.5 to
get the actual rotation in degrees of the node.
* `paramtype2 = "meshoptions"`
* Only valid for "plantlike" drawtype. `param2` encodes the shape and
optional modifiers of the "plant". `param2` is a bitfield.
* Bits 0 to 2 select the shape.
Use only one of the values below:
* 0 = a "x" shaped plant (ordinary plant)
* 1 = a "+" shaped plant (just rotated 45 degrees)
* 2 = a "*" shaped plant with 3 faces instead of 2
* 3 = a "#" shaped plant with 4 faces instead of 2
* 4 = a "#" shaped plant with 4 faces that lean outwards
* 5-7 are unused and reserved for future meshes.
* Bits 3 to 7 are used to enable any number of optional modifiers.
Just add the corresponding value(s) below to `param2`:
* 8 - Makes the plant slightly vary placement horizontally
* 16 - Makes the plant mesh 1.4x larger
* 32 - Moves each face randomly a small bit down (1/8 max)
* values 64 and 128 (bits 6-7) are reserved for future use.
* Example: `param2 = 0` selects a normal "x" shaped plant
* Example: `param2 = 17` selects a "+" shaped plant, 1.4x larger (1+16)
* `paramtype2 = "color"`
* `param2` tells which color is picked from the palette.
The palette should have 256 pixels.
* `paramtype2 = "colorfacedir"`
* Same as `facedir`, but with colors.
* The first three bits of `param2` tells which color is picked from the
palette. The palette should have 8 pixels.
* `paramtype2 = "colorwallmounted"`
* Same as `wallmounted`, but with colors.
* The first five bits of `param2` tells which color is picked from the
palette. The palette should have 32 pixels.
* `paramtype2 = "glasslikeliquidlevel"`
* Only valid for "glasslike_framed" or "glasslike_framed_optional"
drawtypes.
* `param2` values 0-63 define 64 levels of internal liquid, 0 being empty
and 63 being full.
* Liquid texture is defined using `special_tiles = {"modname_tilename.png"}`
* `paramtype2 = "colordegrotate"`
* Same as `degrotate`, but with colors.
* The first (most-significant) three bits of `param2` tells which color
is picked from the palette. The palette should have 8 pixels.
* Remaining 5 bits store rotation in range 0–23 (i.e. in 15° steps)
* `paramtype2 = "none"`
* `param2` will not be used by the engine and can be used to store
an arbitrary value
Nodes can also contain extra data. See [Node Metadata].
Node drawtypes
--------------
There are a bunch of different looking node types.
Look for examples in `games/devtest` or `games/minetest_game`.
* `normal`
* A node-sized cube.
* `airlike`
* Invisible, uses no texture.
* `liquid`
* The cubic source node for a liquid.
* `flowingliquid`
* The flowing version of a liquid, appears with various heights and slopes.
* `glasslike`
* Often used for partially-transparent nodes.
* Only external sides of textures are visible.
* `glasslike_framed`
* All face-connected nodes are drawn as one volume within a surrounding
frame.
* The frame appearance is generated from the edges of the first texture
specified in `tiles`. The width of the edges used are 1/16th of texture
size: 1 pixel for 16x16, 2 pixels for 32x32 etc.
* The glass 'shine' (or other desired detail) on each node face is supplied
by the second texture specified in `tiles`.
* `glasslike_framed_optional`
* This switches between the above 2 drawtypes according to the menu setting
'Connected Glass'.
* `allfaces`
* Often used for partially-transparent nodes.
* External and internal sides of textures are visible.
* `allfaces_optional`
* Often used for leaves nodes.
* This switches between `normal`, `glasslike` and `allfaces` according to
the menu setting: Opaque Leaves / Simple Leaves / Fancy Leaves.
* With 'Simple Leaves' selected, the texture specified in `special_tiles`
is used instead, if present. This allows a visually thicker texture to be
used to compensate for how `glasslike` reduces visual thickness.
* `torchlike`
* A single vertical texture.
* If placed on top of a node, uses the first texture specified in `tiles`.
* If placed against the underside of a node, uses the second texture
specified in `tiles`.
* If placed on the side of a node, uses the third texture specified in
`tiles` and is perpendicular to that node.
* `signlike`
* A single texture parallel to, and mounted against, the top, underside or
side of a node.
* `plantlike`
* Two vertical and diagonal textures at right-angles to each other.
* See `paramtype2 = "meshoptions"` above for other options.
* `firelike`
* When above a flat surface, appears as 6 textures, the central 2 as
`plantlike` plus 4 more surrounding those.
* If not above a surface the central 2 do not appear, but the texture
appears against the faces of surrounding nodes if they are present.
* `fencelike`
* A 3D model suitable for a wooden fence.
* One placed node appears as a single vertical post.
* Adjacently-placed nodes cause horizontal bars to appear between them.
* `raillike`
* Often used for tracks for mining carts.
* Requires 4 textures to be specified in `tiles`, in order: Straight,
curved, t-junction, crossing.
* Each placed node automatically switches to a suitable rotated texture
determined by the adjacent `raillike` nodes, in order to create a
continuous track network.
* Becomes a sloping node if placed against stepped nodes.
* `nodebox`
* Often used for stairs and slabs.
* Allows defining nodes consisting of an arbitrary number of boxes.
* See [Node boxes] below for more information.
* `mesh`
* Uses models for nodes.
* Tiles should hold model materials textures.
* Only static meshes are implemented.
* For supported model formats see Irrlicht engine documentation.
* `plantlike_rooted`
* Enables underwater `plantlike` without air bubbles around the nodes.
* Consists of a base cube at the co-ordinates of the node plus a
`plantlike` extension above with a height of `param2 / 16` nodes.
* The `plantlike` extension visually passes through any nodes above the
base cube without affecting them.
* The base cube texture tiles are defined as normal, the `plantlike`
extension uses the defined special tile, for example:
`special_tiles = {{name = "default_papyrus.png"}},`
`*_optional` drawtypes need less rendering time if deactivated
(always client-side).
Node boxes
----------
Node selection boxes are defined using "node boxes".
A nodebox is defined as any of:
{
-- A normal cube; the default in most things
type = "regular"
}
{
-- A fixed box (or boxes) (facedir param2 is used, if applicable)
type = "fixed",
fixed = box OR {box1, box2, ...}
}
{
-- A variable height box (or boxes) with the top face position defined
-- by the node parameter 'leveled = ', or if 'paramtype2 == "leveled"'
-- by param2.
-- Other faces are defined by 'fixed = {}' as with 'type = "fixed"'.
type = "leveled",
fixed = box OR {box1, box2, ...}
}
{
-- A box like the selection box for torches
-- (wallmounted param2 is used, if applicable)
type = "wallmounted",
wall_top = box,
wall_bottom = box,
wall_side = box
}
{
-- A node that has optional boxes depending on neighbouring nodes'
-- presence and type. See also `connects_to`.
type = "connected",
fixed = box OR {box1, box2, ...}
connect_top = box OR {box1, box2, ...}
connect_bottom = box OR {box1, box2, ...}
connect_front = box OR {box1, box2, ...}
connect_left = box OR {box1, box2, ...}
connect_back = box OR {box1, box2, ...}
connect_right = box OR {box1, box2, ...}
-- The following `disconnected_*` boxes are the opposites of the
-- `connect_*` ones above, i.e. when a node has no suitable neighbour
-- on the respective side, the corresponding disconnected box is drawn.
disconnected_top = box OR {box1, box2, ...}
disconnected_bottom = box OR {box1, box2, ...}
disconnected_front = box OR {box1, box2, ...}
disconnected_left = box OR {box1, box2, ...}
disconnected_back = box OR {box1, box2, ...}
disconnected_right = box OR {box1, box2, ...}
disconnected = box OR {box1, box2, ...} -- when there is *no* neighbour
disconnected_sides = box OR {box1, box2, ...} -- when there are *no*
-- neighbours to the sides
}
A `box` is defined as:
{x1, y1, z1, x2, y2, z2}
A box of a regular node would look like:
{-0.5, -0.5, -0.5, 0.5, 0.5, 0.5},
To avoid collision issues, keep each value within the range of +/- 1.45.
This also applies to leveled nodeboxes, where the final height shall not
exceed this soft limit.
Map terminology and coordinates
===============================
Nodes, mapblocks, mapchunks
---------------------------
A 'node' is the fundamental cubic unit of a world and appears to a player as
roughly 1x1x1 meters in size.
A 'mapblock' (often abbreviated to 'block') is 16x16x16 nodes and is the
fundamental region of a world that is stored in the world database, sent to
clients and handled by many parts of the engine.
'mapblock' is preferred terminology to 'block' to help avoid confusion with
'node', however 'block' often appears in the API.
A 'mapchunk' (sometimes abbreviated to 'chunk') is usually 5x5x5 mapblocks
(80x80x80 nodes) and is the volume of world generated in one operation by
the map generator.
The size in mapblocks has been chosen to optimise map generation.
Coordinates
-----------
### Orientation of axes
For node and mapblock coordinates, +X is East, +Y is up, +Z is North.
### Node coordinates
Almost all positions used in the API use node coordinates.
### Mapblock coordinates
Occasionally the API uses 'blockpos' which refers to mapblock coordinates that
specify a particular mapblock.
For example blockpos (0,0,0) specifies the mapblock that extends from
node position (0,0,0) to node position (15,15,15).
#### Converting node position to the containing blockpos
To calculate the blockpos of the mapblock that contains the node at 'nodepos',
for each axis:
* blockpos = math.floor(nodepos / 16)
#### Converting blockpos to min/max node positions
To calculate the min/max node positions contained in the mapblock at 'blockpos',
for each axis:
* Minimum:
nodepos = blockpos * 16
* Maximum:
nodepos = blockpos * 16 + 15
HUD
===
HUD element types
-----------------
The position field is used for all element types.
To account for differing resolutions, the position coordinates are the
percentage of the screen, ranging in value from `0` to `1`.
The name field is not yet used, but should contain a description of what the
HUD element represents.
The `direction` field is the direction in which something is drawn.
`0` draws from left to right, `1` draws from right to left, `2` draws from
top to bottom, and `3` draws from bottom to top.
The `alignment` field specifies how the item will be aligned. It is a table
where `x` and `y` range from `-1` to `1`, with `0` being central. `-1` is
moved to the left/up, and `1` is to the right/down. Fractional values can be
used.
The `offset` field specifies a pixel offset from the position. Contrary to
position, the offset is not scaled to screen size. This allows for some
precisely positioned items in the HUD.
**Note**: `offset` _will_ adapt to screen DPI as well as user defined scaling
factor!
The `z_index` field specifies the order of HUD elements from back to front.
Lower z-index elements are displayed behind higher z-index elements. Elements
with same z-index are displayed in an arbitrary order. Default 0.
Supports negative values. By convention, the following values are recommended:
* -400: Graphical effects, such as vignette
* -300: Name tags, waypoints
* -200: Wieldhand
* -100: Things that block the player's view, e.g. masks
* 0: Default. For standard in-game HUD elements like crosshair, hotbar,
minimap, builtin statbars, etc.
* 100: Temporary text messages or notification icons
* 1000: Full-screen effects such as full-black screen or credits.
This includes effects that cover the entire screen
* Other: If your HUD element doesn't fit into any category, pick a number
between the suggested values
Below are the specific uses for fields in each type; fields not listed for that
type are ignored.
### `image`
Displays an image on the HUD.
* `scale`: The scale of the image, with 1 being the original texture size.
Only the X coordinate scale is used (positive values).
Negative values represent that percentage of the screen it
should take; e.g. `x=-100` means 100% (width).
* `text`: The name of the texture that is displayed.
* `alignment`: The alignment of the image.
* `offset`: offset in pixels from position.
### `text`
Displays text on the HUD.
* `scale`: Defines the bounding rectangle of the text.
A value such as `{x=100, y=100}` should work.
* `text`: The text to be displayed in the HUD element.
* `number`: An integer containing the RGB value of the color used to draw the
text. Specify `0xFFFFFF` for white text, `0xFF0000` for red, and so on.
* `alignment`: The alignment of the text.
* `offset`: offset in pixels from position.
* `size`: size of the text.
The player-set font size is multiplied by size.x (y value isn't used).
### `statbar`
Displays a horizontal bar made up of half-images with an optional background.
* `text`: The name of the texture to use.
* `text2`: Optional texture name to enable a background / "off state"
texture (useful to visualize the maximal value). Both textures
must have the same size.
* `number`: The number of half-textures that are displayed.
If odd, will end with a vertically center-split texture.
* `item`: Same as `number` but for the "off state" texture
* `direction`: To which direction the images will extend to
* `offset`: offset in pixels from position.
* `size`: If used, will force full-image size to this value (override texture
pack image size)
### `inventory`
* `text`: The name of the inventory list to be displayed.
* `number`: Number of items in the inventory to be displayed.
* `item`: Position of item that is selected.
* `direction`
* `offset`: offset in pixels from position.
### `waypoint`
Displays distance to selected world position.
* `name`: The name of the waypoint.
* `text`: Distance suffix. Can be blank.
* `precision`: Waypoint precision, integer >= 0. Defaults to 10.
If set to 0, distance is not shown. Shown value is `floor(distance*precision)/precision`.
When the precision is an integer multiple of 10, there will be `log_10(precision)` digits after the decimal point.
`precision = 1000`, for example, will show 3 decimal places (eg: `0.999`).
`precision = 2` will show multiples of `0.5`; precision = 5 will show multiples of `0.2` and so on:
`precision = n` will show multiples of `1/n`
* `number:` An integer containing the RGB value of the color used to draw the
text.
* `world_pos`: World position of the waypoint.
* `offset`: offset in pixels from position.
* `alignment`: The alignment of the waypoint.
### `image_waypoint`
Same as `image`, but does not accept a `position`; the position is instead determined by `world_pos`, the world position of the waypoint.
* `scale`: The scale of the image, with 1 being the original texture size.
Only the X coordinate scale is used (positive values).
Negative values represent that percentage of the screen it
should take; e.g. `x=-100` means 100% (width).
* `text`: The name of the texture that is displayed.
* `alignment`: The alignment of the image.
* `world_pos`: World position of the waypoint.
* `offset`: offset in pixels from position.
### `compass`
Displays an image oriented or translated according to current heading direction.
* `size`: The size of this element. Negative values represent percentage
of the screen; e.g. `x=-100` means 100% (width).
* `scale`: Scale of the translated image (used only for dir = 2 or dir = 3).
* `text`: The name of the texture to use.
* `alignment`: The alignment of the image.
* `offset`: Offset in pixels from position.
* `dir`: How the image is rotated/translated:
* 0 - Rotate as heading direction
* 1 - Rotate in reverse direction
* 2 - Translate as landscape direction
* 3 - Translate in reverse direction
If translation is chosen, texture is repeated horizontally to fill the whole element.
### `minimap`
Displays a minimap on the HUD.
* `size`: Size of the minimap to display. Minimap should be a square to avoid
distortion.
* `alignment`: The alignment of the minimap.
* `offset`: offset in pixels from position.
Representations of simple things
================================
Position/vector
---------------
{x=num, y=num, z=num}
For helper functions see [Spatial Vectors].
`pointed_thing`
---------------
* `{type="nothing"}`
* `{type="node", under=pos, above=pos}`
* Indicates a pointed node selection box.
* `under` refers to the node position behind the pointed face.
* `above` refers to the node position in front of the pointed face.
* `{type="object", ref=ObjectRef}`
Exact pointing location (currently only `Raycast` supports these fields):
* `pointed_thing.intersection_point`: The absolute world coordinates of the
point on the selection box which is pointed at. May be in the selection box
if the pointer is in the box too.
* `pointed_thing.box_id`: The ID of the pointed selection box (counting starts
from 1).
* `pointed_thing.intersection_normal`: Unit vector, points outwards of the
selected selection box. This specifies which face is pointed at.
Is a null vector `{x = 0, y = 0, z = 0}` when the pointer is inside the
selection box.
Flag Specifier Format
=====================
Flags using the standardized flag specifier format can be specified in either
of two ways, by string or table.
The string format is a comma-delimited set of flag names; whitespace and
unrecognized flag fields are ignored. Specifying a flag in the string sets the
flag, and specifying a flag prefixed by the string `"no"` explicitly
clears the flag from whatever the default may be.
In addition to the standard string flag format, the schematic flags field can
also be a table of flag names to boolean values representing whether or not the
flag is set. Additionally, if a field with the flag name prefixed with `"no"`
is present, mapped to a boolean of any value, the specified flag is unset.
E.g. A flag field of value
{place_center_x = true, place_center_y=false, place_center_z=true}
is equivalent to
{place_center_x = true, noplace_center_y=true, place_center_z=true}
which is equivalent to
"place_center_x, noplace_center_y, place_center_z"
or even
"place_center_x, place_center_z"
since, by default, no schematic attributes are set.
Items
=====
Item types
----------
There are three kinds of items: nodes, tools and craftitems.
* Node: Can be placed in the world's voxel grid
* Tool: Has a wear property but cannot be stacked. The default use action is to
dig nodes or hit objects according to its tool capabilities.
* Craftitem: Cannot dig nodes or be placed
Amount and wear
---------------
All item stacks have an amount between 0 and 65535. It is 1 by
default. Tool item stacks can not have an amount greater than 1.
Tools use a wear (damage) value ranging from 0 to 65535. The
value 0 is the default and is used for unworn tools. The values
1 to 65535 are used for worn tools, where a higher value stands for
a higher wear. Non-tools always have a wear value of 0.
Item formats
------------
Items and item stacks can exist in three formats: Serializes, table format
and `ItemStack`.
When an item must be passed to a function, it can usually be in any of
these formats.
### Serialized
This is called "stackstring" or "itemstring". It is a simple string with
1-3 components: the full item identifier, an optional amount and an optional
wear value. Syntax:
[[ ]]
Examples:
* `'default:apple'`: 1 apple
* `'default:dirt 5'`: 5 dirt
* `'default:pick_stone'`: a new stone pickaxe
* `'default:pick_wood 1 21323'`: a wooden pickaxe, ca. 1/3 worn out
### Table format
Examples:
5 dirt nodes:
{name="default:dirt", count=5, wear=0, metadata=""}
A wooden pick about 1/3 worn out:
{name="default:pick_wood", count=1, wear=21323, metadata=""}
An apple:
{name="default:apple", count=1, wear=0, metadata=""}
### `ItemStack`
A native C++ format with many helper methods. Useful for converting
between formats. See the [Class reference] section for details.
Groups
======
In a number of places, there is a group table. Groups define the
properties of a thing (item, node, armor of entity, capabilities of
tool) in such a way that the engine and other mods can can interact with
the thing without actually knowing what the thing is.
Usage
-----
Groups are stored in a table, having the group names with keys and the
group ratings as values. Group ratings are integer values within the
range [-32767, 32767]. For example:
-- Default dirt
groups = {crumbly=3, soil=1}
-- A more special dirt-kind of thing
groups = {crumbly=2, soil=1, level=2, outerspace=1}
Groups always have a rating associated with them. If there is no
useful meaning for a rating for an enabled group, it shall be `1`.
When not defined, the rating of a group defaults to `0`. Thus when you
read groups, you must interpret `nil` and `0` as the same value, `0`.
You can read the rating of a group for an item or a node by using
minetest.get_item_group(itemname, groupname)
Groups of items
---------------
Groups of items can define what kind of an item it is (e.g. wool).
Groups of nodes
---------------
In addition to the general item things, groups are used to define whether
a node is destroyable and how long it takes to destroy by a tool.
Groups of entities
------------------
For entities, groups are, as of now, used only for calculating damage.
The rating is the percentage of damage caused by tools with this damage group.
See [Entity damage mechanism].
object.get_armor_groups() --> a group-rating table (e.g. {fleshy=100})
object.set_armor_groups({fleshy=30, cracky=80})
Groups of tools
---------------
Groups in tools define which groups of nodes and entities they are
effective towards.
Groups in crafting recipes
--------------------------
An example: Make meat soup from any meat, any water and any bowl:
{
output = 'food:meat_soup_raw',
recipe = {
{'group:meat'},
{'group:water'},
{'group:bowl'},
},
-- preserve = {'group:bowl'}, -- Not implemented yet (TODO)
}
Another example: Make red wool from white wool and red dye:
{
type = 'shapeless',
output = 'wool:red',
recipe = {'wool:white', 'group:dye,basecolor_red'},
}
Special groups
--------------
The asterisk `(*)` after a group name describes that there is no engine
functionality bound to it, and implementation is left up as a suggestion
to games.
### Node, item and tool groups
* `not_in_creative_inventory`: (*) Special group for inventory mods to indicate
that the item should be hidden in item lists.
### Node-only groups
* `attached_node`: if the node under it is not a walkable block the node will be
dropped as an item. If the node is wallmounted the wallmounted direction is
checked.
* `bouncy`: value is bounce speed in percent
* `connect_to_raillike`: makes nodes of raillike drawtype with same group value
connect to each other
* `dig_immediate`: Player can always pick up node without reducing tool wear
* `2`: the node always gets the digging time 0.5 seconds (rail, sign)
* `3`: the node always gets the digging time 0 seconds (torch)
* `disable_jump`: Player (and possibly other things) cannot jump from node
or if their feet are in the node. Note: not supported for `new_move = false`
* `fall_damage_add_percent`: modifies the fall damage suffered when hitting
the top of this node. There's also an armor group with the same name.
The final player damage is determined by the following formula:
damage =
collision speed
* ((node_fall_damage_add_percent + 100) / 100) -- node group
* ((player_fall_damage_add_percent + 100) / 100) -- player armor group
- (14) -- constant tolerance
Negative damage values are discarded as no damage.
* `falling_node`: if there is no walkable block under the node it will fall
* `float`: the node will not fall through liquids
* `level`: Can be used to give an additional sense of progression in the game.
* A larger level will cause e.g. a weapon of a lower level make much less
damage, and get worn out much faster, or not be able to get drops
from destroyed nodes.
* `0` is something that is directly accessible at the start of gameplay
* There is no upper limit
* See also: `leveldiff` in [Tools]
* `slippery`: Players and items will slide on the node.
Slipperiness rises steadily with `slippery` value, starting at 1.
### Tool-only groups
* `disable_repair`: If set to 1 for a tool, it cannot be repaired using the
`"toolrepair"` crafting recipe
### `ObjectRef` armor groups
* `immortal`: Skips all damage and breath handling for an object. This group
will also hide the integrated HUD status bars for players. It is
automatically set to all players when damage is disabled on the server and
cannot be reset (subject to change).
* `fall_damage_add_percent`: Modifies the fall damage suffered by players
when they hit the ground. It is analog to the node group with the same
name. See the node group above for the exact calculation.
* `punch_operable`: For entities; disables the regular damage mechanism for
players punching it by hand or a non-tool item, so that it can do something
else than take damage.
Known damage and digging time defining groups
---------------------------------------------
* `crumbly`: dirt, sand
* `cracky`: tough but crackable stuff like stone.
* `snappy`: something that can be cut using fine tools; e.g. leaves, small
plants, wire, sheets of metal
* `choppy`: something that can be cut using force; e.g. trees, wooden planks
* `fleshy`: Living things like animals and the player. This could imply
some blood effects when hitting.
* `explody`: Especially prone to explosions
* `oddly_breakable_by_hand`:
Can be added to nodes that shouldn't logically be breakable by the
hand but are. Somewhat similar to `dig_immediate`, but times are more
like `{[1]=3.50,[2]=2.00,[3]=0.70}` and this does not override the
speed of a tool if the tool can dig at a faster speed than this
suggests for the hand.
Examples of custom groups
-------------------------
Item groups are often used for defining, well, _groups of items_.
* `meat`: any meat-kind of a thing (rating might define the size or healing
ability or be irrelevant -- it is not defined as of yet)
* `eatable`: anything that can be eaten. Rating might define HP gain in half
hearts.
* `flammable`: can be set on fire. Rating might define the intensity of the
fire, affecting e.g. the speed of the spreading of an open fire.
* `wool`: any wool (any origin, any color)
* `metal`: any metal
* `weapon`: any weapon
* `heavy`: anything considerably heavy
Digging time calculation specifics
----------------------------------
Groups such as `crumbly`, `cracky` and `snappy` are used for this
purpose. Rating is `1`, `2` or `3`. A higher rating for such a group implies
faster digging time.
The `level` group is used to limit the toughness of nodes a tool can dig
and to scale the digging times / damage to a greater extent.
**Please do understand this**, otherwise you cannot use the system to it's
full potential.
Tools define their properties by a list of parameters for groups. They
cannot dig other groups; thus it is important to use a standard bunch of
groups to enable interaction with tools.
Tools
=====
Tools definition
----------------
Tools define:
* Full punch interval
* Maximum drop level
* For an arbitrary list of groups:
* Uses (until the tool breaks)
* Maximum level (usually `0`, `1`, `2` or `3`)
* Digging times
* Damage groups
### Full punch interval
When used as a weapon, the tool will do full damage if this time is spent
between punches. If e.g. half the time is spent, the tool will do half
damage.
### Maximum drop level
Suggests the maximum level of node, when dug with the tool, that will drop
it's useful item. (e.g. iron ore to drop a lump of iron).
This is not automated; it is the responsibility of the node definition
to implement this.
### Uses
Determines how many uses the tool has when it is used for digging a node,
of this group, of the maximum level. For lower leveled nodes, the use count
is multiplied by `3^leveldiff`.
`leveldiff` is the difference of the tool's `maxlevel` `groupcaps` and the
node's `level` group. The node cannot be dug if `leveldiff` is less than zero.
* `uses=10, leveldiff=0`: actual uses: 10
* `uses=10, leveldiff=1`: actual uses: 30
* `uses=10, leveldiff=2`: actual uses: 90
### Maximum level
Tells what is the maximum level of a node of this group that the tool will
be able to dig.
### Digging times
List of digging times for different ratings of the group, for nodes of the
maximum level.
For example, as a Lua table, `times={2=2.00, 3=0.70}`. This would
result in the tool to be able to dig nodes that have a rating of `2` or `3`
for this group, and unable to dig the rating `1`, which is the toughest.
Unless there is a matching group that enables digging otherwise.
If the result digging time is 0, a delay of 0.15 seconds is added between
digging nodes; If the player releases LMB after digging, this delay is set to 0,
i.e. players can more quickly click the nodes away instead of holding LMB.
### Damage groups
List of damage for groups of entities. See [Entity damage mechanism].
Example definition of the capabilities of a tool
------------------------------------------------
tool_capabilities = {
full_punch_interval=1.5,
max_drop_level=1,
groupcaps={
crumbly={maxlevel=2, uses=20, times={[1]=1.60, [2]=1.20, [3]=0.80}}
}
damage_groups = {fleshy=2},
}
This makes the tool be able to dig nodes that fulfil both of these:
* Have the `crumbly` group
* Have a `level` group less or equal to `2`
Table of resulting digging times:
crumbly 0 1 2 3 4 <- level
-> 0 - - - - -
1 0.80 1.60 1.60 - -
2 0.60 1.20 1.20 - -
3 0.40 0.80 0.80 - -
level diff: 2 1 0 -1 -2
Table of resulting tool uses:
-> 0 - - - - -
1 180 60 20 - -
2 180 60 20 - -
3 180 60 20 - -
**Notes**:
* At `crumbly==0`, the node is not diggable.
* At `crumbly==3`, the level difference digging time divider kicks in and makes
easy nodes to be quickly breakable.
* At `level > 2`, the node is not diggable, because it's `level > maxlevel`
Entity damage mechanism
=======================
Damage calculation:
damage = 0
foreach group in cap.damage_groups:
damage += cap.damage_groups[group]
* limit(actual_interval / cap.full_punch_interval, 0.0, 1.0)
* (object.armor_groups[group] / 100.0)
-- Where object.armor_groups[group] is 0 for inexistent values
return damage
Client predicts damage based on damage groups. Because of this, it is able to
give an immediate response when an entity is damaged or dies; the response is
pre-defined somehow (e.g. by defining a sprite animation) (not implemented;
TODO).
Currently a smoke puff will appear when an entity dies.
The group `immortal` completely disables normal damage.
Entities can define a special armor group, which is `punch_operable`. This
group disables the regular damage mechanism for players punching it by hand or
a non-tool item, so that it can do something else than take damage.
On the Lua side, every punch calls:
entity:on_punch(puncher, time_from_last_punch, tool_capabilities, direction,
damage)
This should never be called directly, because damage is usually not handled by
the entity itself.
* `puncher` is the object performing the punch. Can be `nil`. Should never be
accessed unless absolutely required, to encourage interoperability.
* `time_from_last_punch` is time from last punch (by `puncher`) or `nil`.
* `tool_capabilities` can be `nil`.
* `direction` is a unit vector, pointing from the source of the punch to
the punched object.
* `damage` damage that will be done to entity
Return value of this function will determine if damage is done by this function
(retval true) or shall be done by engine (retval false)
To punch an entity/object in Lua, call:
object:punch(puncher, time_from_last_punch, tool_capabilities, direction)
* Return value is tool wear.
* Parameters are equal to the above callback.
* If `direction` equals `nil` and `puncher` does not equal `nil`, `direction`
will be automatically filled in based on the location of `puncher`.
Metadata
========
Node Metadata
-------------
The instance of a node in the world normally only contains the three values
mentioned in [Nodes]. However, it is possible to insert extra data into a node.
It is called "node metadata"; See `NodeMetaRef`.
Node metadata contains two things:
* A key-value store
* An inventory
Some of the values in the key-value store are handled specially:
* `formspec`: Defines a right-click inventory menu. See [Formspec].
* `infotext`: Text shown on the screen when the node is pointed at
Example:
local meta = minetest.get_meta(pos)
meta:set_string("formspec",
"size[8,9]"..
"list[context;main;0,0;8,4;]"..
"list[current_player;main;0,5;8,4;]")
meta:set_string("infotext", "Chest");
local inv = meta:get_inventory()
inv:set_size("main", 8*4)
print(dump(meta:to_table()))
meta:from_table({
inventory = {
main = {[1] = "default:dirt", [2] = "", [3] = "", [4] = "",
[5] = "", [6] = "", [7] = "", [8] = "", [9] = "",
[10] = "", [11] = "", [12] = "", [13] = "",
[14] = "default:cobble", [15] = "", [16] = "", [17] = "",
[18] = "", [19] = "", [20] = "default:cobble", [21] = "",
[22] = "", [23] = "", [24] = "", [25] = "", [26] = "",
[27] = "", [28] = "", [29] = "", [30] = "", [31] = "",
[32] = ""}
},
fields = {
formspec = "size[8,9]list[context;main;0,0;8,4;]list[current_player;main;0,5;8,4;]",
infotext = "Chest"
}
})
Item Metadata
-------------
Item stacks can store metadata too. See [`ItemStackMetaRef`].
Item metadata only contains a key-value store.
Some of the values in the key-value store are handled specially:
* `description`: Set the item stack's description.
See also: `get_description` in [`ItemStack`]
* `short_description`: Set the item stack's short description.
See also: `get_short_description` in [`ItemStack`]
* `color`: A `ColorString`, which sets the stack's color.
* `palette_index`: If the item has a palette, this is used to get the
current color from the palette.
Example:
local meta = stack:get_meta()
meta:set_string("key", "value")
print(dump(meta:to_table()))
Formspec
========
Formspec defines a menu. This supports inventories and some of the
typical widgets like buttons, checkboxes, text input fields, etc.
It is a string, with a somewhat strange format.
A formspec is made out of formspec elements, which includes widgets
like buttons but also can be used to set stuff like background color.
Many formspec elements have a `name`, which is a unique identifier which
is used when the server receives user input. You must not use the name
"quit" for formspec elements.
Spaces and newlines can be inserted between the blocks, as is used in the
examples.
Position and size units are inventory slots unless the new coordinate system
is enabled. `X` and `Y` position the formspec element relative to the top left
of the menu or container. `W` and `H` are its width and height values.
If the new system is enabled, all elements have unified coordinates for all
elements with no padding or spacing in between. This is highly recommended
for new forms. See `real_coordinates[]` and `Migrating to Real
Coordinates`.
Inventories with a `player:` inventory location are only sent to the
player named ``.
When displaying text which can contain formspec code, e.g. text set by a player,
use `minetest.formspec_escape`.
For coloured text you can use `minetest.colorize`.
Since formspec version 3, elements drawn in the order they are defined. All
background elements are drawn before all other elements.
**WARNING**: do _not_ use a element name starting with `key_`; those names are
reserved to pass key press events to formspec!
**WARNING**: Minetest allows you to add elements to every single formspec instance
using `player:set_formspec_prepend()`, which may be the reason backgrounds are
appearing when you don't expect them to, or why things are styled differently
to normal. See [`no_prepend[]`] and [Styling Formspecs].
Examples
--------
### Chest
size[8,9]
list[context;main;0,0;8,4;]
list[current_player;main;0,5;8,4;]
### Furnace
size[8,9]
list[context;fuel;2,3;1,1;]
list[context;src;2,1;1,1;]
list[context;dst;5,1;2,2;]
list[current_player;main;0,5;8,4;]
### Minecraft-like player inventory
size[8,7.5]
image[1,0.6;1,2;player.png]
list[current_player;main;0,3.5;8,4;]
list[current_player;craft;3,0;3,3;]
list[current_player;craftpreview;7,1;1,1;]
Version History
---------------
* FORMSPEC VERSION 1:
* (too much)
* FORMSPEC VERSION 2:
* Forced real coordinates
* background9[]: 9-slice scaling parameters
* FORMSPEC VERSION 3:
* Formspec elements are drawn in the order of definition
* bgcolor[]: use 3 parameters (bgcolor, formspec (now an enum), fbgcolor)
* box[] and image[] elements enable clipping by default
* new element: scroll_container[]
* FORMSPEC VERSION 4:
* Allow dropdown indexing events
Elements
--------
### `formspec_version[]`
* Set the formspec version to a certain number. If not specified,
version 1 is assumed.
* Must be specified before `size` element.
* Clients older than this version can neither show newer elements nor display
elements with new arguments correctly.
* Available since feature `formspec_version_element`.
* See also: [Version History]
### `size[,,]`
* Define the size of the menu in inventory slots
* `fixed_size`: `true`/`false` (optional)
* deprecated: `invsize[,;]`
### `position[,]`
* Must be used after `size` element.
* Defines the position on the game window of the formspec's `anchor` point.
* For X and Y, 0.0 and 1.0 represent opposite edges of the game window,
for example:
* [0.0, 0.0] sets the position to the top left corner of the game window.
* [1.0, 1.0] sets the position to the bottom right of the game window.
* Defaults to the center of the game window [0.5, 0.5].
### `anchor[,]`
* Must be used after both `size` and `position` (if present) elements.
* Defines the location of the anchor point within the formspec.
* For X and Y, 0.0 and 1.0 represent opposite edges of the formspec,
for example:
* [0.0, 1.0] sets the anchor to the bottom left corner of the formspec.
* [1.0, 0.0] sets the anchor to the top right of the formspec.
* Defaults to the center of the formspec [0.5, 0.5].
* `position` and `anchor` elements need suitable values to avoid a formspec
extending off the game window due to particular game window sizes.
### `no_prepend[]`
* Must be used after the `size`, `position`, and `anchor` elements (if present).
* Disables player:set_formspec_prepend() from applying to this formspec.
### `real_coordinates[]`
* INFORMATION: Enable it automatically using `formspec_version` version 2 or newer.
* When set to true, all following formspec elements will use the new coordinate system.
* If used immediately after `size`, `position`, `anchor`, and `no_prepend` elements
(if present), the form size will use the new coordinate system.
* **Note**: Formspec prepends are not affected by the coordinates in the main form.
They must enable it explicitly.
* For information on converting forms to the new coordinate system, see `Migrating
to Real Coordinates`.
### `container[,]`
* Start of a container block, moves all physical elements in the container by
(X, Y).
* Must have matching `container_end`
* Containers can be nested, in which case the offsets are added
(child containers are relative to parent containers)
### `container_end[]`
* End of a container, following elements are no longer relative to this
container.
### `scroll_container[,;,;;;]`
* Start of a scroll_container block. All contained elements will ...
* take the scroll_container coordinate as position origin,
* be additionally moved by the current value of the scrollbar with the name
`scrollbar name` times `scroll factor` along the orientation `orientation` and
* be clipped to the rectangle defined by `X`, `Y`, `W` and `H`.
* `orientation`: possible values are `vertical` and `horizontal`.
* `scroll factor`: optional, defaults to `0.1`.
* Nesting is possible.
* Some elements might work a little different if they are in a scroll_container.
* Note: If you want the scroll_container to actually work, you also need to add a
scrollbar element with the specified name. Furthermore, it is highly recommended
to use a scrollbaroptions element on this scrollbar.
### `scroll_container_end[]`
* End of a scroll_container, following elements are no longer bound to this
container.
### `list[;;,;,;]`
* Show an inventory list if it has been sent to the client. Nothing will
be shown if the inventory list is of size 0.
* **Note**: With the new coordinate system, the spacing between inventory
slots is one-fourth the size of an inventory slot by default. Also see
[Styling Formspecs] for changing the size of slots and spacing.
### `list[;;,;,;]`
* Show an inventory list if it has been sent to the client. Nothing will
be shown if the inventory list is of size 0.
* **Note**: With the new coordinate system, the spacing between inventory
slots is one-fourth the size of an inventory slot.
### `listring[;]`
* Allows to create a ring of inventory lists
* Shift-clicking on items in one element of the ring
will send them to the next inventory list inside the ring
* The first occurrence of an element inside the ring will
determine the inventory where items will be sent to
### `listring[]`
* Shorthand for doing `listring[;]`
for the last two inventory lists added by list[...]
### `listcolors[;]`
* Sets background color of slots as `ColorString`
* Sets background color of slots on mouse hovering
### `listcolors[;;]`
* Sets background color of slots as `ColorString`
* Sets background color of slots on mouse hovering
* Sets color of slots border
### `listcolors[;;;;]`
* Sets background color of slots as `ColorString`
* Sets background color of slots on mouse hovering
* Sets color of slots border
* Sets default background color of tooltips
* Sets default font color of tooltips
### `tooltip[;;;]`
* Adds tooltip for an element
* `bgcolor` tooltip background color as `ColorString` (optional)
* `fontcolor` tooltip font color as `ColorString` (optional)
### `tooltip[,;,;;;]`
* Adds tooltip for an area. Other tooltips will take priority when present.
* `bgcolor` tooltip background color as `ColorString` (optional)
* `fontcolor` tooltip font color as `ColorString` (optional)
### `image[,;,;]`
* Show an image
### `animated_image[,;,;;;;;]`
* Show an animated image. The image is drawn like a "vertical_frames" tile
animation (See [Tile animation definition]), but uses a frame count/duration
for simplicity
* `name`: Element name to send when an event occurs. The event value is the index of the current frame.
* `texture name`: The image to use.
* `frame count`: The number of frames animating the image.
* `frame duration`: Milliseconds between each frame. `0` means the frames don't advance.
* `frame start` (Optional): The index of the frame to start on. Default `1`.
### `model[,;,;;;;;;;;]`
* Show a mesh model.
* `name`: Element name that can be used for styling
* `mesh`: The mesh model to use.
* `textures`: The mesh textures to use according to the mesh materials.
Texture names must be separated by commas.
* `rotation {X,Y}` (Optional): Initial rotation of the camera.
The axes are euler angles in degrees.
* `continuous` (Optional): Whether the rotation is continuous. Default `false`.
* `mouse control` (Optional): Whether the model can be controlled with the mouse. Default `true`.
* `frame loop range` (Optional): Range of the animation frames.
* Defaults to the full range of all available frames.
* Syntax: `,`
* `animation speed` (Optional): Sets the animation speed. Default 0 FPS.
### `item_image[,;,;]`
* Show an inventory image of registered item/node
### `bgcolor[;;]`
* Sets background color of formspec.
* `bgcolor` and `fbgcolor` (optional) are `ColorString`s, they define the color
of the non-fullscreen and the fullscreen background.
* `fullscreen` (optional) can be one of the following:
* `false`: Only the non-fullscreen background color is drawn. (default)
* `true`: Only the fullscreen background color is drawn.
* `both`: The non-fullscreen and the fullscreen background color are drawn.
* `neither`: No background color is drawn.
* Note: Leave a parameter empty to not modify the value.
* Note: `fbgcolor`, leaving parameters empty and values for `fullscreen` that
are not bools are only available since formspec version 3.
### `background[,;,;]`
* Example for formspec 8x4 in 16x resolution: image shall be sized
8 times 16px times 4 times 16px.
### `background[,;,;;]`
* Example for formspec 8x4 in 16x resolution:
image shall be sized 8 times 16px times 4 times 16px
* If `auto_clip` is `true`, the background is clipped to the formspec size
(`x` and `y` are used as offset values, `w` and `h` are ignored)
### `background9[,;,;;;]`
* 9-sliced background. See https://en.wikipedia.org/wiki/9-slice_scaling
* Middle is a rect which defines the middle of the 9-slice.
* `x` - The middle will be x pixels from all sides.
* `x,y` - The middle will be x pixels from the horizontal and y from the vertical.
* `x,y,x2,y2` - The middle will start at x,y, and end at x2, y2. Negative x2 and y2 values
will be added to the width and height of the texture, allowing it to be used as the
distance from the far end.
* All numbers in middle are integers.
* Example for formspec 8x4 in 16x resolution:
image shall be sized 8 times 16px times 4 times 16px
* If `auto_clip` is `true`, the background is clipped to the formspec size
(`x` and `y` are used as offset values, `w` and `h` are ignored)
* Available since formspec version 2
### `pwdfield[,;,;;