Need advices on painted clouds generation

Hello everyone !

I stumbled upon this Sketchfab scene : Ship in Clouds - Download Free 3D model by Bastien Genbrugge (@bastienBGR) [c475323] - Sketchfab

I would love to recreate something like this in UE4.
What do you think would be the best way to procede to make the clouds ?

I want them to be easy to generate and they will probably shown in high numbers.
But I don’t really know where to begin with.

Should I do some kind of mesh generation ? A shader ?

Thank you