MC-BE-LevelDB-Key-Calculator

Minecraft Bedrock Edition LevelDB Key Calculator

A calculator to generate the hex keys for retrieving data from a Minecraft: Bedrock Edition LDB (chunk data) database

Overview

This is a very simple tool used to convert world coordinates into chunk hex keys. Chunk hex keys are used to access sections of the LDB containing chunk data.

Using the Tool

First step is to clone the repo and cd into it, go ahead and do that and come back here after.

Command Options

Command Syntax

go run main.go hexkey [OPTIONS]

For example, running the following:

go run main.go hexkey -x 413 -z 54 -y 105 -type nether -tag PendingTicks

produces:

190000003000000ffffffff3306

Hex Key Format

Minecraft Gamepedia Link: https://minecraft.gamepedia.com/Bedrock_Edition_level_format

<LE Chunk X Coord><LE Chunk Z Coord>[<Nether Key | End Key>]<Tag Byte><BE SubChunk Y Coord>

For example, using the coordinates X: 413, Y: 105, Z: 54, the coresponding chunk key is (split by section):

19000000 03000000 2f 06

Another example, using the coordinates X: 110, Y: 2, Z: -22 with chunk coord format, the coresponding chunk key is (split by section):

6e000000 eaffffff 2f 02

Legend:

Manually Calculating a Hex Key

X, Y, Z is the typical coordinate order, but when dealing with the data we find X, Z, Y is the order of greatest-to-least significance, which is why this explanation tends to express X, Z, Y ordering.

All division below is of course integer division. The remainder/modulus will be used to find the byte offset within the subchunk data. X, Z, and dimension are 32-bit signed integers in little endian byte order. In the examples below, I've bolded the chunk Z coordinate for clarity.

Each chunk is 16x16x256 (X, Z, Y), and the subchunk block data keys are 16 high. So for x, z, y coordinates of 413, 54, 105:

• chunk X = 413 / 16 = 25 or 0x19 signed 32-bit integer in little endian byte order ([0x19,0, 0, 0] == 19000000)
• chunk Z = 54 / 16 = 3 ([0x3, 0, 0, 0] == 03000000)

So all keys beginning with 1900000003000000 are about this coordinate's chunk. (In the overworld; other dimensions add a 32-bit dimension ID, so the same coordinates in the Nether I think have keys that start with 1900000003000000ffffffff and 190000000300000001000000 for the End.)

The tags and subchunk indexes are 8-bit values. (Unsigned? Not sure it matters as there are no negative Y chunk coordinates and no tags < 0 or > 127.)

47 ([0x2F]) is the subchunk prefix tag, so all keys beginning with 19000000030000002f are the Y subchunks for this coordinate.

• subchunk Y = 105 / 16 = 6 ([0x06])

So, the subchunk key for X=413, Z=54, Y=105 is 19000000030000002f06

Attribution: This section was taken from the README.md on the McpeTool repo, see here for the full document: https://github.com/midnightfreddie/McpeTool/tree/master/docs#how-to-convert-world-coordinates-to-leveldb-keys