WorldGen Editor

WorldGen Editor is a JSON-driven Minecraft world generation mod for Minecraft 1.21.1.

It adds a datapack-style world preset named WorldGen Editor: Islands. The preset keeps vanilla noise generation as the base, then uses a custom island biome source and density function to turn the Overworld into a configurable archipelago.

The project is built with Architectury Loom and targets:

• Fabric
• Forge
• NeoForge

Features

• Configurable islands from config/worldgen_editor/continents.json.
• Simple island fields such as x, z, radius, rotation, shape_power, roughness, and shore_width.
• JSON entry types for normal islands, ocean-carved cuts, and generated archipelagos.
• Per-entry biome exclusions with exclude_biomes, including biome ids and tags.
• Climate-aware ocean and land fallback biome selection.
• Backward-compatible support for older field names such as center_x, center_z, x_divisor, and z_divisor.
• Built-in world preset: WorldGen Editor: Islands.
• Runtime commands for reload and per-world enable state.
• Separate preview tool for developers: WorldGen Editor Preview.

Requirements

• Java 21
• Minecraft 1.21.1
• Gradle wrapper included in this repository

Loader dependency notes:

• Fabric requires Fabric Loader, Fabric API, and Architectury API.
• NeoForge requires NeoForge and Architectury API.
• Forge uses the native Forge API path for 1.21.1.

Building

From the project root:

.\gradlew.bat build --no-daemon

On Linux or macOS:

./gradlew build --no-daemon

The production jars are created here:

fabric/build/libs/worldgen-editor-fabric-0.2 beta.jar
forge/build/libs/worldgen-editor-forge-0.2 beta.jar
neoforge/build/libs/worldgen-editor-neoforge-0.2 beta.jar

For convenience, the root build task also copies the three loader-ready jars into:

release/

You can run the copy task directly:

.\gradlew.bat releaseJars --no-daemon

The version is controlled by mod_version in gradle.properties.

Project Layout

common/    Shared config, island mask, commands, codecs, and datapack-style worldgen resources
fabric/    Fabric entrypoint and metadata
forge/     Forge entrypoint and metadata
neoforge/  NeoForge entrypoint and metadata

Important shared resources:

common/src/main/resources/data/worldgen_editor/worldgen/world_preset/islands.json
common/src/main/resources/data/worldgen_editor/worldgen/noise_settings/island_overworld.json
common/src/main/resources/assets/worldgen_editor/default_continents.json

Using The Mod

Install the jar for your loader, then create a new world and select:

WorldGen Editor: Islands

The mod reads:

config/worldgen_editor/continents.json

If the file does not exist, the mod creates a default config.

Changing the config does not rebuild old chunks. Use this command after editing the file:

/worldgen_editor reload

Reload affects newly generated chunks only.

Commands

/worldgen_editor enable
/worldgen_editor disable
/worldgen_editor status
/worldgen_editor reload

Generation is enabled only when both the global config and the per-world state are enabled:

continents.json enabled && <world>/worldgen_editor/worldgen_editor.json enabled

Config Guide

See JSON_GUIDE.md for the full continents.json format, examples, compatibility fields, and troubleshooting notes.

Minimal example:

{
  "enabled": true,
  "entries": [
    {
      "x": 0,
      "z": 0,
      "radius": 850
    }
  ]
}

Preview Tool

The companion preview tool is located outside this repository folder: WorldGen Editor Preview

Open index.html in a browser to preview island masks without generating Minecraft worlds.

License

WorldGen Editor is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

See LICENSE.txt.