minetest/doc/world_format.md

Minetest World Format 22...29

This applies to a world format carrying the block serialization version 22...27, used at least in

• 0.4.dev-20120322 ... 0.4.dev-20120606 (22...23)
• 0.4.0 (23)
• 24 was never released as stable and existed for ~2 days
• 27 was added in 0.4.15-dev
• 29 was added in 5.5.0-dev

The block serialization version does not fully specify every aspect of this format; if compliance with this format is to be checked, it needs to be done by detecting if the files and data indeed follows it.

Files

Everything is contained in a directory, the name of which is freeform, but often serves as the name of the world.

Currently, the authentication and ban data is stored on a per-world basis. It can be copied over from an old world to a newly created world.

World
├── auth.txt ───── Authentication data
├── auth.sqlite ── Authentication data (SQLite alternative)
├── env_meta.txt ─ Environment metadata
├── ipban.txt ──── Banned IPs/users
├── map_meta.txt ─ Map metadata
├── map.sqlite ─── Map data
├── players ────── Player directory
│   │── player1 ── Player file
│   └── Foo ────── Player file
└── world.mt ───── World metadata

auth.txt

Contains authentication data, one player per line.

<name>:<password hash>:<privilege1,...>

Legacy format (until 0.4.12) of password hash is <name><password> SHA1'd, in base64.

Format (since 0.4.13) of password hash is #1#<salt>#<verifier>, with the parts inside <> encoded in base64.

<verifier> is an RFC 2945 compatible SRP verifier, of the given salt, password, and the player's name lowercased, using the 2048-bit group specified in RFC 5054 and the SHA-256 hash function.

Example lines:

• Player "celeron55", no password, privileges "interact" and "shout":

  celeron55::interact,shout
  

• Player "Foo", password "bar", privilege "shout", with a legacy password hash:

  foo:iEPX+SQWIR3p67lj/0zigSWTKHg:shout
  

• Player "Foo", password "bar", privilege "shout", with a 0.4.13 password hash:

  foo:#1#hPpy4O3IAn1hsNK00A6wNw#Kpu6rj7McsrPCt4euTb5RA5ltF7wdcWGoYMcRngwDi11cZhPuuR9i5Bo7o6A877TgcEwoc//HNrj9EjR/CGjdyTFmNhiermZOADvd8eu32FYK1kf7RMC0rXWxCenYuOQCG4WF9mMGiyTPxC63VAjAMuc1nCZzmy6D9zt0SIKxOmteI75pAEAIee2hx4OkSXRIiU4Zrxo1Xf7QFxkMY4x77vgaPcvfmuzom0y/fU1EdSnZeopGPvzMpFx80ODFx1P34R52nmVl0W8h4GNo0k8ZiWtRCdrJxs8xIg7z5P1h3Th/BJ0lwexpdK8sQZWng8xaO5ElthNuhO8UQx1l6FgEA:shout
  

• Player "bar", no password, no privileges:

  bar::
  

auth.sqlite

Contains authentication data as an SQLite database. This replaces auth.txt above when auth_backend is set to sqlite3 in world.mt.

This database contains two tables: auth and user_privileges:

CREATE TABLE `auth` (
    `id` INTEGER PRIMARY KEY AUTOINCREMENT,
    `name` VARCHAR(32) UNIQUE,
    `password` VARCHAR(512),
    `last_login` INTEGER
);
CREATE TABLE `user_privileges` (
    `id` INTEGER,
    `privilege` VARCHAR(32),
    PRIMARY KEY (id, privilege),
    CONSTRAINT fk_id FOREIGN KEY (id) REFERENCES auth (id) ON DELETE CASCADE
);

The name and password fields of the auth table are the same as the auth.txt fields (with modern password hash). The last_login field is the last login time as a Unix time stamp.

The user_privileges table contains one entry per privilege and player. A player with "interact" and "shout" privileges will have two entries, one with privilege="interact" and the second with privilege="shout".

env_meta.txt

Simple global environment variables.

Example content:

game_time = 73471
time_of_day = 19118
EnvArgsEnd

ipban.txt

Banned IP addresses and usernames.

Example content:

123.456.78.9|foo
123.456.78.10|bar

map_meta.txt

Simple global map variables.

Example content:

seed = 7980462765762429666
[end_of_params]

map.sqlite

Map data.

See Map File Format below.

player1, Foo

Player data.

Filename can be anything.

See Player File Format below.

world.mt

World metadata.

gameid = mesetint             - name of the game
enable_damage = true          - whether damage is enabled or not
creative_mode = false         - whether creative mode is enabled or not
backend = sqlite3             - which DB backend to use for blocks (sqlite3, dummy, leveldb, redis, postgresql)
player_backend = sqlite3      - which DB backend to use for player data
readonly_backend = sqlite3    - optionally read-only seed DB (DB file _must_ be located in "readonly" subfolder)
auth_backend = files          - which DB backend to use for authentication data
mod_storage_backend = sqlite3 - which DB backend to use for mod storage
server_announce = false       - whether the server is publicly announced or not
load_mod_<mod> = false        - whether <mod> is to be loaded in this world

For load_mod_<mod>, the possible values are:

• false - Do not load the mod.
• true - Load the mod from wherever it is found (may cause conflicts if the same mod appears also in some other place).
• mods/modpack/moddir - Relative path to the mod
  • Must be one of the following:
    • mods/: mods in the user path's mods folder (ex. /home/user/.minetest/mods)
    • share/: mods in the share's mods folder (ex. /usr/share/minetest/mods)
    • /path/to/env: you can use absolute paths to mods inside folders specified with the MINETEST_MOD_PATH env variable.
  • Other locations and absolute paths are not supported.
  • Note that moddir is the directory name, not the mod name specified in mod.conf.

PostgreSQL backend specific settings:

pgsql_connection = host=127.0.0.1 port=5432 user=mt_user password=mt_password dbname=minetest
pgsql_player_connection = (same parameters as above)
pgsql_readonly_connection = (same parameters as above)
pgsql_auth_connection = (same parameters as above)
pgsql_mod_storage_connection = (same parameters as above)

Redis backend specific settings:

redis_address = 127.0.0.1  - Redis server address
redis_hash = foo           - Database hash
redis_port = 6379          - (optional) Connection port
redis_password = hunter2   - (optional) Server password

Player File Format

Should be pretty self-explanatory.

Note

: Position is in nodes * 10

Example content:

hp = 11
name = celeron55
pitch = 39.77
position = (-5231.97,15,1961.41)
version = 1
yaw = 101.37
PlayerArgsEnd
List main 32
Item default:torch 13
Item default:pick_steel 1 50112
Item experimental:tnt
Item default:cobble 99
Item default:pick_stone 1 13104
Item default:shovel_steel 1 51838
Item default:dirt 61
Item default:rail 78
Item default:coal_lump 3
Item default:cobble 99
Item default:leaves 22
Item default:gravel 52
Item default:axe_steel 1 2045
Item default:cobble 98
Item default:sand 61
Item default:water_source 94
Item default:glass 2
Item default:mossycobble
Item default:pick_steel 1 64428
Item animalmaterials:bone
Item default:sword_steel
Item default:sapling
Item default:sword_stone 1 10647
Item default:dirt 99
Empty
Empty
Empty
Empty
Empty
Empty
Empty
Empty
EndInventoryList
List craft 9
Empty
Empty
Empty
Empty
Empty
Empty
Empty
Empty
Empty
EndInventoryList
List craftpreview 1
Empty
EndInventoryList
List craftresult 1
Empty
EndInventoryList
EndInventory

Map File Format

Minetest maps consist of MapBlocks, chunks of 16x16x16 nodes.

In addition to the bulk node data, MapBlocks stored on disk also contain other things.

History

Initially, Minetest stored maps in a format called the "sectors" format. It was a directory/file structure like this:

sectors2/XXX/ZZZ/YYYY

For example, the MapBlock at (0, 1, -2) was this file:

sectors2/000/ffd/0001

Eventually Minetest outgrew this directory structure, as filesystems were struggling under the number of files and directories.

Large servers seriously needed a new format, and thus the base of the current format was invented, suggested by celeron55 and implemented by JacobF.

SQLite3 was implemented. Blocks files were directly inserted as blobs in a single table, indexed by integer primary keys, which were hashed coordinates.

Today, we know that SQLite3 allows multiple primary keys (which would allow storing coordinates separately), but the format has been kept unchanged for that part.

map.sqlite

map.sqlite is a SQLite3 database, containing a single table, called blocks. It looks like this:

CREATE TABLE `blocks` (`pos` INT NOT NULL PRIMARY KEY, `data` BLOB);

Position Hashing

pos (a node position hash) is created from the three coordinates of a MapBlock using this algorithm, defined here in Python:

def getBlockAsInteger(p):
    return int64(p[2]*16777216 + p[1]*4096 + p[0])

def int64(u):
    while u >= 2**63:
        u -= 2**64
    while u <= -2**63:
        u += 2**64
    return u

It can be converted the other way by using this code:

def getIntegerAsBlock(i):
    x = unsignedToSigned(i % 4096, 2048)
    i = int((i - x) / 4096)
    y = unsignedToSigned(i % 4096, 2048)
    i = int((i - y) / 4096)
    z = unsignedToSigned(i % 4096, 2048)
    return x,y,z

def unsignedToSigned(i, max_positive):
    if i < max_positive:
        return i
    else:
        return i - 2*max_positive

Blob

The blob is the data that would have otherwise gone into the file.

See below for description.

MapBlock Serialization Format

Notes:

• NOTE: Byte order is MSB first (big-endian).
• NOTE: Zlib data is in such a format that Python's zlib at least can directly decompress.
• NOTE: Since version 29 zstd is used instead of zlib. In addition, the entire block is first serialized and then compressed (except the version byte).

u8 version

• map format version number, see serialization.h for the latest number

u8 flags

• Flag bitmasks:

  • 0x01: is_underground: Should be set to 0 if there will be no light obstructions above the block. If/when sunlight of a block is updated and there is no block above it, this value is checked for determining whether sunlight comes from the top.

  • 0x02: day_night_differs: Whether the lighting of the block is different on day and night. Only blocks that have this bit set are updated when day transforms to night.

  • 0x04: lighting_expired: Not used in version 27 and above. If true, lighting is invalid and should be updated. If you can't calculate lighting in your generator properly, you could try setting this 1 to everything and setting the uppermost block in every sector as is_underground=0. It most likely won't work properly.

  • 0x08: generated: True if the block has been generated. If false, block is mostly filled with CONTENT_IGNORE and is likely to contain e.g. parts of trees of neighboring blocks.

u16 lighting_complete

• Added in version 27.

• This contains 12 flags, each of them corresponds to a direction.

• Indicates if the light is correct at the sides of a map block. Lighting may not be correct if the light changed, but a neighbor block was not loaded at that time. If these flags are false, Minetest will automatically recompute light when both this block and its required neighbor are loaded.

• The bit order is: nothing, nothing, nothing, nothing, night X-, night Y-, night Z-, night Z+, night Y+, night X+, day X-, day Y-, day Z-, day Z+, day Y+, day X+. Where 'day' is for the day light bank, 'night' is for the night light bank. The 'nothing' bits should be always set, as they will be used to indicate if direct sunlight spreading is finished.

• Example: if the block at (0, 0, 0) has lighting_complete = 0b1111111111111110, Minetest will correct lighting in the day light bank when the block at (1, 0, 0) is also loaded.

Timestamp and node ID mappings were introduced in map format version 29.

• u32 timestamp

  • Timestamp when last saved, as seconds from starting the game.
  • 0xffffffff = invalid/unknown timestamp, nothing should be done with the time difference when loaded

• u8 name_id_mapping_version

  • Should be zero for map format version 29.

• u16 num_name_id_mappings

  • foreach num_name_id_mappings:
    • u16 id
    • u16 name_len
    • u8[name_len] name

u8 content_width

• Number of bytes in the content (param0) fields of nodes
• 1 byte before map format version 24, 2 bytes since

u8 params_width

• Number of bytes used for parameters per node
• Always 2

Node Data

Note

: Zlib-compressed before map format version 29

• If content_width is 1:

  • u8[4096]: param0 fields
  • u8[4096]: param1 fields
  • u8[4096]: param2 fields

• If content_width is 2:

  • u16[4096]: param0 fields
  • u8[4096]: param1 fields
  • u8[4096]: param2 fields

• The location of a node in each of those arrays is (z*16*16 + y*16 + x).

Node Metadata List

Note

: Zlib-compressed before map version format 29

• Before map format version 23:

  • u16 version (=1)
  • u16 count of metadata
  • foreach count:
    • u16 position ((p.Z*MAP_BLOCKSIZE*MAP_BLOCKSIZE + p.Y*MAP_BLOCKSIZE + p.X))
    • u16 type_id
    • u16 content_size
    • u8[content_size] content of metadata. Format depends on type_id, see below.

• Since map format version 23:

  • u8 version

    Note

    : Type was u16 before map format version 23

    • = 1 before map format version 28
    • = 2 since map format version 28
  • u16 count of metadata
  • foreach count:
    • u16 position ((p.Z*MAP_BLOCKSIZE*MAP_BLOCKSIZE + p.Y*MAP_BLOCKSIZE + p.X))
    • u32 num_vars
    • foreach num_vars:
      • u16 key_len
      • u8[key_len] key
      • u32 val_len
      • u8[val_len] value
      • u8 is_private
      • only since map format version 2. 0 = not private, 1 = private
    • serialized inventory

Node Timers

• Map format version 23:

  • u8 unused version (always 0)

• Map format version 24:

  Note

  : Not released as stable

  • u8 nodetimer_version
  • if nodetimer_version == 1:
    • u16 num_of_timers
    • foreach num_of_timers:
      • u16 timer position ((z*16*16 + y*16 + x))
      • s32 timeout * 1000
      • s32 elapsed * 1000

• Since map format version 25:

  • u8 length of the data of a single timer (always 2+4+4=10)
  • u16 num_of_timers
  • foreach num_of_timers:
    • u16 timer position ((z*16*16 + y*16 + x))
    • s32 timeout * 1000
    • s32 elapsed * 1000

u8 static object version:

• Always 0

u16 static_object_count

foreach static_object_count:

• u8 type (object type-id)
• s32 pos_x_nodes * 10000
• s32 pos_y_nodes * 10000
• s32 pos_z_nodes * 10000
• u16 data_size
• u8[data_size] data

Before map format version 29:

• u32 timestamp

  • Same meaning as the timestamp further up

• u8 name-id-mapping version

  • Always 0

• u16 num_name_id_mappings

  • foreach num_name_id_mappings:
    • u16 id
    • u16 name_len
    • u8[name_len] name

End of File (EOF).

Format of Nodes

A node is composed of the u8 fields param0, param1 and param2.

Before map format version 24:

• The content id of a node is determined as so:
  • If param0 < 0x80, content_id = param0
  • Otherwise, content_id = (param0<<4) + (param2>>4)

Since map format version 24:

• The content id of a node is param0.

The purpose of param1 and param2 depend on the definition of the node.

Name-ID-Mapping

The mapping maps node content IDs to node names.

Node Metadata Format (Before Map Format Version 23)

The node metadata is serialized depending on the type_id field.

1: Generic metadata

• serialized inventory
• u32 len
• u8[len] text
• u16 len
• u8[len] owner
• u16 len
• u8[len] infotext
• u16 len
• u8[len] inventory drawspec
• u8 allow_text_input (bool)
• u8 removal_disabled (bool)
• u8 enforce_owner (bool)
• u32 num_vars
• foreach num_vars:
  • u16 len
  • u8[len] name
  • u32 len
  • u8[len] value

14: Sign metadata

• u16 text_len
• u8[text_len] text

15: Chest metadata

• serialized inventory

16: Furnace metadata

• To be determined

17: Locked Chest metadata

• u16 len
• u8[len] owner
• serialized inventory

Static Objects

Static objects are persistent freely moving objects in the world.

Object types: 1: Test object 7: LuaEntity:

• u8 compatibility_byte (always 1)
• u16 len
• u8[len] entity name
• u32 len
• u8[len] static data
• s16 hp
• s32 velocity.x * 10000
• s32 velocity.y * 10000
• s32 velocity.z * 10000
• s32 yaw * 1000

Since protocol version 37:

• u8 version2 (=1)
• s32 pitch * 1000
• s32 roll * 1000

Itemstring Format

Examples:

• 'default:dirt 5'
• 'default:pick_wood 21323'
• '"default:apple" 2'
• 'default:apple'

Older formats:

• 'node "default:dirt" 5'
• 'NodeItem default:dirt 5'
• 'ToolItem WPick 21323'

The wear value in tools is 0...65535.

Inventory Serialization Format

• The inventory serialization format is line-based.
• The newline character used is \n
• The end condition of a serialized inventory is always EndInventory\n
• All the slots in a list must always be serialized.

Example

List foo 4
Item default:sapling
Item default:sword_stone 1 10647
Item default:dirt 99
Empty
EndInventoryList
List bar 9
Empty
Empty
Empty
Empty
Empty
Empty
Empty
Empty
Empty
EndInventoryList
EndInventory