I built a volumetric cloud system that uses Smoke, Particle Emitters, etc to create really realistic clouds. The clouds are created with a function that allows me to control density, size, position, height, etc and then it places the clouds around and changes the opacity of the Particle Emitters using the density value and trigonometry.
Clouds have different variations each time I know the lag is crazy but most of the lag is actually caused by the screen recorder as you can see. I had to use another screen recorder because my windows one was glitching out. If you have any questions let me know.