JS - How to create minecraft-style clouds?

I'm currently developing a kind of block game (compare Minecraft) for the browser and am teaching three.js.

I want to add some kind of clouds to my world (as you can see on the picture) - but I have some problems generating them dynamically.

In my opinion, everything is best done per noise - but how exactly do I have to use this to add such clouds? - The clouds I generate look really horrible compared to that :D

I am looking forward to any help!

Minecraft clouds


How to use a noise function to generate these clouds?

Note: This is the noise function I use: https://github.com/josephg/noisejs


My three.js code:

noise.seed(Math.random());
let cloudsGeometry = new THREE.Geometry();
let cloudSize = {
  width: 100,
  height: 40,
  depth: 100
}

for (let x = 0; x < 100; x++) {
  for (let z = 0; z < 100; z++) {
    let value = noise.simplex2(x / 100, z / 100);
    if (Math.abs(value) > 0.2) continue;
    let geometry = new THREE.BoxGeometry(cloudSize.width, cloudSize.height, cloudSize.depth);
    let cube = new THREE.Mesh(geometry);
    cube.position.z = z * cloudSize.depth
    cube.position.x = x * cloudSize.width
    cube.updateMatrix()
    cloudsGeometry.merge(cube.geometry, cube.matrix)
  }
}

scene.add(new THREE.Mesh(cloudsGeometry, new THREE.MeshBasicMaterial({
  color: 0xffffff
})));

This is how my clouds looks like with the code above:

enter image description here