Alpha level format


Info

Minecraft Infdev This is not an official version history or changelog. For the official list, please visit the Minecraft website. For versions 1.11 and prior, please check the Mojang website. For versions prior to Beta 1.8, please minecraft introduced a new data storage challenge while under development: Terrain generated in infdev has the potential to be almost 235 petabytes, which is 240,640 terabytes, in size when stored in memory, due to the sheer size of the map (several times the surface area of the Earth). Therefore, to reduce file size and memory usage, Notch decided to split the terrain into 16⃗128⃗16 chunks and store them on disk when not visible. In addition, terrain is only generated when it is within the drawing distance of the player`s camera, significantly reducing save size, since most players will only be able to search a tiny fraction of the map in a reasonable time frame. Minecraft Alpha Alpha Starting version Alpha 1.0.0 (Jun. 28, 2010) Latest version Alpha 1.2.6 (Dec. 3, 2010) Paid Yes Alpha versions 1.0.0 to 1.2.6 are available to play in the launcher. Be that as it may, please note that these versions minecraft uses this technique, and both Minecraft Beta Beta Starting version Beta 1.0 (Dec. 20, 2010) Latest version Beta 1.9-pre6 (Nov. 13, 2011) Paid Yes These versions are available to play in the launcher. Be that as it may, please note that these versions contain bugs. You ll minecraft and Minecraft 1.0 Minecraft 1.0 Starting version 1.0.0 (Nov. 18th, 2011) Latest version 1.12 Paid Yes Website http://www.minecraft.net/ See the official releaseAnnounce of Minecraft for the PC. For the version, see 1.0.0. For the first minecraft still use the general concept because of its success.

In Minecraft Beta 1.3 Beta 1.3 Release date Feb. 22, 2011 Download Client Server Other editions of 1.3 Java Edition ◄◄ Beta 1.2 ◄ Beta 1.2_02 Beta 1.3_01 ► Beta 1.4 ►► See the computer edition. minecraft , this format was superseded by the Region file format The Region file format is a storage format for Minecraft chunks introduced in Minecraft Beta 1.3, in which groups of 32×32 chunks are stored in a region file. This file format took the place of minecraft , where chunks are stored in groups of 32⃗32 in region files.

World folder structure

An Alpha level is actually a single folder containing at least one file named level.dat. There is also a session.lock file to make sure only one Minecraft opens the level at once.

The level folder may have up to 64 subfolders, each with up to 64 additional subfolders each. These folders contain the chunk files that hold the level`s terrain and entities. Each chunk file is identified by its chunk position xPos and zPos. The varying parts of the chunk file`s name are obtained by taking the base36 representation of the xPos and zPos. The names of the folders that the chunk file is placed in are found by taking xPos and zPos, modulo 64 (or bitwise ANDing with 63), and converting to base36. Negative coordinates must be interpreted as positive numbers, bitwise, via two`s complement. So, -13 is treated as 243 (if its size is a byte).

As an example, to find the chunk at position (-13, 44):

  • The first folder name is base36(-13⃂% 64). This is base36(243⃂% 64 = 51) which is "1f".
  • The second folder name is base36(44⃂% 64). This is base36(44) which is "18".
  • The chunk file`s name is "c." + base36(-13) + "." + base36(44) + ".dat". This evaluates to "c.-d.18.dat"
  • Thus, the chunk at (-13, 44) is stored in "1f/18/c.-d.18.dat"

Each chunk remembers its position independently of the file and folder names. See below to find out how to read a chunk`s position from the file data.

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Dimensions

Dimensions are saved in the same way normal worlds are, but instead of mixing the world files inside the save folder, the files are stored in an additional sub-folders with their own region and chunk data. Their names start with DIM, followed by the dimension ID.

These dimension IDs were used in Alpha:

ID Folder Dimension
0 saves/World/ Normal world (Overworld), always stored in the world folder without DIM
-1 saves/World/DIM-1/ The Nether A view of the Nether. The Nether is a hell-like dimension, filled with fire, lava, and dangerous mobs. Contents 1 Accessing 2 Environment 2.1 Mobs 3 Generation 3.1 Naturally generated 3.2 Naturally created 3.3 Structures minecraft , added with the Halloween Update See the 2010 Halloween Update. For the 2012 Halloween update, see Pretty Scary Update. A complete list of what Notch hoped to finish for the update. A complete list of what Notch minecraft

session.lock Format

session.lock contains the timestamp of when the world was last touched. The file is eight bytes long, and contains a single 64-bit signed integer in big endian format. The value of this integer is the timestamp, stored as the number of milliseconds elapsed since 1970, in UTC.

Unlike typical lock files, session.lock ensures that the LAST program to open a world is that one that owns it. The process goes something like this:

  1. program opens session.lock
  2. program writes timestamp to session.lock
  3. program monitors session.lock for changes
  4. if the contents of session.lock change, program aborts and gives up its lock on the world.

level.dat Format

The level.dat file is a GZip`d NBT See the NBT file format. For using NBT in commands, see Tutorials/Command NBT Tags. The Named Binary Tag format is used by Minecraft for the various files in which it saves data. minecraft file that stores global level data (time of day, player health, inventory, velocity, and position within the map, etc.). Most importantly, it stores the Random Seed that the terrain generator uses to seamlessly generate more terrain on the fly.

This file has this structure:

Chunk Format

Chunk files, as described above, are GZip`d NBT See the NBT file format. For using NBT in commands, see Tutorials/Command NBT Tags. The Named Binary Tag format is used by Minecraft for the various files in which it saves data. minecraft files. They have this structure:


  • The root tag.

    • Level: The level data in this chunk.

      • xPos: The X chunk coordinate.

      • zPos: The Z chunk coordinate.

      • TerrainPopulated: 1 or 0 (true/false) - true if Minecraft has generated special featuresSpecial attraction in this chunk such as trees, flowers, ores, dungeons.

      • LastUpdate: The tick when the chunk as last updated.

      • Blocks: 32768 bytes of Block IDs, 8 bits per block.

      • Data: 16384 bytes of Block Data, 4 bits per block.

      • BlockLight: 16384 bytes of Block Light, 4 bits per block.

      • SkyLight: 16384 bytes of Sky Light, 4 bits per block.

      • HeightMap: 256 bytes of Height Map information, 8 bits per XZ column. Used for speeding up sky light calculations.

      • Entities: List of TAG_Compounds, one for each entity in the chunk.

        • An entity.
          • See Chunk format → Entity Format - not all information is applicable to Minecraft Alpha.

      • TileEntities: List of TAG_Compounds, one for each tile entity in the chunk.

        • A tile entity.
          • See Chunk format → Tile Entity Format - not all information is applicable to Minecraft Alpha.