Always use the latest (stable) version!

SeedMapper

In-game Minecraft Fabric mod that allows you to do various things with the world seed. For reference, have a look at the features this mod has. Keep in mind though, this mod requires you to have access to the seed. If the seed is not known, you could crack it using SeedCrackerX by 19MisterX98. For questions and support please head to my Discord.

Installation

1. Install the Fabric Loader.
2. Download the Fabric API and move it to your mods folder:
   • Linux/Windows: .minecraft/mods.
   • Mac: minecraft/mods.
3. Download SeedMapper from the releases page and move it to your mods folder.

IMPORTANT

You need to have Java 23 installed to use this mod. I recommend to get Java 23 from adoptium.net. Next, configure your Minecraft launcher to use this release of Java.

• Vanilla launcher: Go to Installations -> Edit -> More options -> Java executable.
• MultiMC: Go to Edit Instance -> Settings -> Java -> Java Installation.
• PrismLauncher: Go to Settings -> Java -> Java Runtime -> Auto-Detect....
  • Do not forget to enable "Skip Java compatibility checks".

If you run into issues, contact your launcher's support.

Features

Before using any of these commands, make sure the seed has been configured using /cconfig seedmapper Seed set <seed>.

Biome locating

Usage: /sm:locate biome <biome>

Locates a given biome closest to the player. All biomes in all dimensions are supported.

Structure locating

Usage: /sm:locate feature structure <structure>[<pieces>]{<variants>}

Locates a given structure closest to the player. All structures in all dimensions are supported. However, due to limitations in the underlying library, some structures (in particular desert pyramids, jungle temples and woodland mansions) may result in occasional false positives. For more advanced querying you can also use piece and variant data to further restrict the search. For example, the following command will search for end cities with ships: /sm:locate feature structure end_city[end_ship].

Slime chunk locating

Usage: /sm:locate feature slimechunk

Locates a slime chunk closest to the player. This will always be accurate.

Source mutation

Usage: /sm:source (run)|(as <entity>)|(positioned <position>)|(rotated <rotation>)|(in <dimension>)|(versioned <version>)|(seeded <seed>)

Executes a given command from a modified source. For example, modifying the source's position will execute the command as if you were in that position. This command is really powerful, use it!

Building from source

This mod internally uses (a fork of) the C library cubiomes by Cubitect. Java bindings for this library were created with (also a fork of) jextract. The bindings use the Foreign Function & Memory API from Project Panama. See CreateJavaBindingsTask.java for the Gradle task that automates this.

To build the mod locally, follow these steps:

1. Compile cubiomes to a shared library. The following is for Windows:

   gcc -shared -o src/main/resources/cubiomes.dll src/main/c/noise.c src/main/c/biomes.c src/main/c/layers.c src/main/c/biomenoise.c src/main/c/generator.c src/main/c/finders.c src/main/c/util.c src/main/c/quadbase.c -O3

2. Install LLVM (version 13.0.0 is recommended) and set the environment variable LLVM_HOME to the directory where LLVM was installed.
3. Compile jextract:

   cd jextract
   ./gradlew --stacktrace -Pjdk_home=$JAVA_HOME -Pllvm_home=$LLVM_HOME clean verify

4. Build the mod:

   ./gradlew build

   You should find the Java bindings in src/main/java/com/github/cubiomes.