How to make realistic sky and cloud in 2.8?

sky texture not work on eevee.
I am thinking something like the default cloud of the unreal engine.
Is there a function that can be easily created with 2.8?

Even if texture is put on sphere, it will not become real.

For Clouds

thanks.but too heavy for realtime.

Render it out and use the images realtime? I’m not sure if Eevee supports movie and animated textures yet though.

thanks
i will try by world texture like unreal