minecraft-assets/data/minecraft/worldgen/density_function/overworld/caves/spaghetti_2d_thickness_modulator.json

{
  "type": "minecraft:cache_once",
  "argument": {
    "type": "minecraft:add",
    "argument1": -0.95,
    "argument2": {
      "type": "minecraft:mul",
      "argument1": -0.35000000000000003,
      "argument2": {
        "type": "minecraft:noise",
        "noise": "minecraft:spaghetti_2d_thickness",
        "xz_scale": 2.0,
        "y_scale": 1.0
      }
    }
  }
}