CoalMod

A data-driven mod for Hytale that adds coal ore to world generation using only JSON files - no Java code required!

Overview

CoalMod demonstrates the data-driven approach to adding ores using WorldGenOverlayLib. This mod contains:

• Zero Java code - completely JSON-based
• Overlay configuration file
• Ore definition files (Coal.json and CoalPlacement.json for each zone)

How It Works

CoalMod uses WorldGenOverlayLib's auto-discovery feature:

1. The overlay configuration is defined in Server/WorldGenOverlays/overlays.json
2. WorldGenOverlayLib's AutoOverlayPlugin automatically discovers and registers the overlay
3. All coal ore files are placed in the Ores/ZoneX/ structure
4. Placement references are automatically merged into Caves.json files for all relevant zones

File Structure

CoalMod/
└── Server/
    ├── WorldGenOverlays/
    │   └── overlays.json          (overlay configuration)
    └── World/
        └── Default/
            └── Ores/
                ├── Zone0/
                │   ├── Coal.json
                │   └── CoalPlacement.json
                ├── Zone1/
                │   ├── Coal.json
                │   └── CoalPlacement.json
                ├── Zone2/
                │   ├── Coal.json
                │   └── CoalPlacement.json
                ├── Zone3/
                │   ├── Coal.json
                │   └── CoalPlacement.json
                └── Zone4/
                    ├── Coal.json
                    └── CoalPlacement.json

Configuration

The overlay is configured in Server/WorldGenOverlays/overlays.json:

{
  "Overlays": [
    {
      "Name": "Coal Ore Overlay",
      "Generator": "Default",
      "Ores": ["Coal"],
      "Zones": [
        "Zone0",
        "Zone1",
        "Zone2",
        "Zone3",
        "Zone4"
      ]
    }
  ]
}

Configuration Fields:

• Name (optional): Display name for the overlay
• Generator (required): World generator name (usually "Default")
• Ores (required): Array of ore names (e.g., ["Coal"]) - all ores share the same zones
• Zones (required): Array of ore zone numbers ("Zone0" through "Zone4") - applies to all ores

Dependencies

• WorldGenOverlayLib: Required for overlay discovery and merging
• Hytale:WorldGen: Required for world generation

Building

Since this is a data-driven mod with no Java code, building is simple:

./gradlew build

The build will:

• Process resources (including manifest.json)
• Package everything into a JAR
• No Java compilation needed!

Installation

1. Build WorldGenOverlayLib first:

   cd ../WorldGenOverlayLib
   ./gradlew build publishToMavenLocal

2. Build CoalMod:

   cd ../CoalMod
   ./gradlew build

3. Install both mods to your Hytale server:

   • Copy WorldGenOverlayLib/build/libs/WorldGenOverlayLib-1.0.0.jar to your server's mods/ folder
   • Copy CoalMod/build/libs/CoalMod-1.0.0.jar to your server's mods/ folder

Benefits of Data-Driven Approach

• No Java Knowledge Required: Just edit JSON files
• Easy to Modify: Change zones by editing the config
• Easy to Share: Distribute as a resource pack - no compilation needed
• Version Control Friendly: JSON files are easy to diff and merge
• Quick Iteration: Change config and rebuild - no code compilation

Customization

To customize CoalMod:

1. Add/Remove Zones: Edit overlays.json and modify the Zones array
2. Modify Ore Generation: Edit the Coal.json files in each zone folder
3. Adjust Ore Placement: Edit the CoalPlacement.json files to change density, height ranges, block masks, etc.

Example: Adding a New Zone

Simply add the zone number to the Zones array in overlays.json:

"Zones": [
  "Zone0",
  "Zone1",
  "Zone2",
  "Zone3",
  "Zone4",
  "Zone5"  // Add this (if Zone5 exists in Hytale)
]

Make sure you have the corresponding Coal.json and CoalPlacement.json files in:

Server/World/Default/Ores/Zone5/

License

See LICENSE file for details.