Default Generators format

{
   "id":"mod_id:block_id",
   "weight":95.5,
   "dimensions":[
      "mod_id:dimension_id",
      "mod_id:dimension_id"
   ],
   "excludedDimensions":[
      "mod_id:dimension_id",
      "mod_id:dimension_id"
   ],
   "minY":0,
   "maxY":69
}

Custom Generators format

{
   "generatorType (cobbleGen/stoneGen/basaltGen)":{
      "mod_id:modifier_block_id":[
         {
            "id":"mod_id:block_id",
            "weight":95.5,
            "dimensions":[
               "mod_id:dimension_id",
               "mod_id:dimension_id"
            ],
            "excludedDimensions":[
               "mod_id:dimension_id",
               "mod_id:dimension_id"
            ],
            "minY":0,
            "maxY":69
         }
      ]
   }
}

Explanation

• All but id and weight are optional, you can remove them if you don't need it, for example:

  {
    "id": "minecraft:bedrock",
    "weight": 1.0,  // as you can see, there's only id and weight here
  }
  

• Custom gen only:
  • generatorType: Need to be replaced by either cobbleGen, stoneGen, or basaltGen
  • mod_id:modifier_block_id: Need to be replaced by modifier block id of your choice (e.g. minecraft:bedrock)
  • id: Block id of the generated block (e.g. minecraft:iron_ore)
  • weight: Weight of the generated block (bigger number = more common)
  • dimensions: Collection of dimension ids where the block can be generated (It's an array!, e.g. ["minecraft:the_end", "minecraft:nether"])
  • excludedDimensions: Collection of dimension ids where the block can NOT generate (It's an array!, e.g. ["minecraft:the_end", "minecraft:nether"])
  • minY: How deep can this block be generated (e.g. 0 means can only be generated from height limit to Y=0 (inclusive))
  • maxY: How high can this block be generated (e.g. 0 means can only be generated from bedrock level to Y=0 (inclusive))

{
  // Cobblestone Generator
  // { "id": "mod_id:block_id", "weight": 95.5 }
  "cobbleGen": [
    {
      "id": "minecraft:cobbled_deepslate",
      "weight": 100.0,
      "maxY": 0
    }
  ],
  // Stone Generator
  // { "id": "mod_id:block_id", "weight": 95.5 }
  "stoneGen": [
    {
      "id": "minecraft:stone",
      "weight": 100.0
    }
  ],
  // Basalt Generator
  // { "id": "mod_id:block_id", "weight": 95.5 }
  "basaltGen": [
    {
      "id": "minecraft:basalt",
      "weight": 100.0
    }
  ]
}

{
  // Custom Generator
  // <stoneGen|cobbleGen>: { <modifier block id>: [ { "id": <block id>, "weight": <randomness weight> }, ... ] }
  "customGen": {
    // Cobblestone Generator
    // { "id": "mod_id:block_id", "weight": 95.5 }
    "cobbleGen": {
      "minecraft:bedrock": [
        {
          "id": "minecraft:emerald_ore",
          "weight": 2.0
        },
        {
          "id": "minecraft:diamond_ore",
          "weight": 5.0
        },
        {
          "id": "minecraft:lapis_ore",
          "weight": 8.0
        },
        {
          "id": "minecraft:gold_ore",
          "weight": 10.0
        },
        {
          "id": "minecraft:iron_ore",
          "weight": 15.0
        },
        {
          "id": "minecraft:coal_ore",
          "weight": 20.0
        },
        {
          "id": "minecraft:cobblestone",
          "weight": 40.0
        }
      ]
    },
    // Stone Generator
    // { "id": "mod_id:block_id", "weight": 95.5 }
    "stoneGen": {
      "minecraft:bedrock": [
        {
          "id": "minecraft:stone",
          "weight": 40.0
        },
        {
          "id": "minecraft:diorite",
          "weight": 20.0
        },
        {
          "id": "minecraft:andesite",
          "weight": 20.0
        },
        {
          "id": "minecraft:granite",
          "weight": 20.0
        }
      ]
    },
    // Basalt Generator
    // { "id": "mod_id:block_id", "weight": 95.5 }
    "basaltGen": {
      "minecraft:bedrock": [
        {
          "id": "minecraft:end_stone",
          "weight": 100.0,
          "dimensions": [
            "minecraft:the_end"
          ]
        },
        {
          "id": "minecraft:blackstone",
          "weight": 100.0,
          "excludedDimensions": [
            "minecraft:the_end"
          ]
        }
      ]
    }
  }
}

{
  // Advanced Custom Generator (Custom Fluid Interaction)
  // Basic format:
  // "advanced": { <source fluid id>: { <neighbour fluid/block id>: { results: {<modifier block id>: [ { "id": <block id>, "weight": <randomness weight> }, ... ] } } } }
  "advanced": {
    // Make sure to use still version of the fluid for this one,
    // - "minecraft:lava" not "minecraft:flowing_lava"
    // - "milk:still_milk" not "milk:flowing_milk"
    // How the fluid's ID is constructed depends on how the corresponding mod creator does things.
    "minecraft:lava": {
      // replicates minecraft cobblestone and stone generator
      // This one can be flowing or still version of the fluid, if still doesn't work try flowing.
      "minecraft:water": {
        // stone generator
        "resultsFromTop": {
          "*": [  // wildcard, accept any block as modifier
            {
              "id": "minecraft:stone",
              "weight": 100.0,
            }
          ]
        },
        // cobblestone generator
        "results": {
          "*": [  // wildcard, accept any block as modifier
            {
              "id": "minecraft:cobblestone",
              "weight": 100.0,
            }
          ]
        }
      },
      // replicates minecraft basalt generator
      "b:minecraft:blue_ice": {
        "results": {
          "minecraft:soul_soil": [
            {
              "id": "minecraft:basalt",
              "weight": 100.0,
            }
          ]
        }
      },
      // custom andesite generator with basalt generator method
      "b:minecraft:water_cauldron": {
        "silent": true,  // prevent extinguish sound from playing
        "results": {
          "*": [
            {
              "id": "minecraft:andesite",
              "weight": 100.0,
            }
          ]
        }
      }
    },
    "milk:still_milk": {
      "b:minecraft:cobblestone": {
        "results": {
          "*": [
            {
              "id": "minecraft:diorite",
              "weight": 100.0,
            }
          ]
        }
      }
    }
  }
}