code: function randomInBox(box, v) {
      v = v || new three.Vector3();
  
      v.x = three.Math.randFloat(box.min.x, box.max.x);
      v.y = three.Math.randFloat(box.min.y, box.max.y);
      v.z = three.Math.randFloat(box.min.z, box.max.z);
  
      return v;
    }
docs: Get a random vector between box.min and box.max.
  
  @param {THREE.Box3} box THREE.Box3 instance.
  @param {THREE.Vector3=} v Optional vector to store result in.
  @returns {THREE.Vector3}