I understand that I can make something similar by layering photos of real clouds in photoshop. But I suppose that there is a way to generate procedurally in some software. Could you please point me in the direction of what to google?
To generate realistic looking clouds procedurally will be really difficult. I’d suggest starting from photos. If you have access to substance designer, you could try something like this:
If you just need a cloud-like noise, then you can take the already existing noises as a starting point and layer up different frequencies of detail. But it’ll tend to look very procedurally generated.
Alternatively you could try generating individual clouds on EmberGen and scattering them, or maybe a carpet of clouds and then try to make that tile. Truly depends on what you’re trying to do with this texture!