definitions/feature_rules/plains_first_double_plant_grass_feature.json

{
  "format_version": "1.13.0",
  "minecraft:feature_rules": {
    "description": {
      "identifier": "minecraft:plains_first_double_plant_grass_feature",
      "places_feature": "minecraft:grass_double_plant_patch_feature"
    },
    "conditions": {
      "placement_pass": "first_pass",
      "minecraft:biome_filter": [
        {
          "test": "has_biome_tag",
          "operator": "==",
          "value": "plains"
        }
      ]
    },
    "distribution": {
      "iterations": 7,
      "scatter_chance": "((query.noise((variable.originx + 8) / 200.0, (variable.originz + 8) / 200.0) >= -.8) && variable.is_legacy == 0.0) ? 100.0 : 0.0",
      "x": {
        "distribution": "uniform",
        "extent": [ 0, 16 ]
      },
      "y": {
        "distribution": "uniform",
        "extent": [ 0, "query.heightmap(variable.worldx, variable.worldz) + 32" ]
      },
      "z": {
        "distribution": "uniform",
        "extent": [ 0, 16 ]
      }
    }
  }
}