I understand this effect can be achieved in 3D rendering programs, but I also believe that it can be achieved through a raster editor like Photoshop. I work in Affinity Photo on iPad, so I’ll need to be able to translate any workflow into there. I’ve tried liquifying brush strokes, and it gets close, but doesn’t quite accomplish what I’m going for. Other threads I’ve researched recommend normal/gradient maps, but that seems like a lot of work for still not quite what I’m trying to do. Whatever it is I need to do seems to be reliant upon color palette and texture. Have been searching forever for an answer!
Two more instances of this effect:
I was able to come pretty close pretty quickly in Affinity Photo – I could only take a couple minutes for this as I’m on a production rush right now I’m afraid.
I made a simple gradient fill, took that into the liquify persona and did some serious liquifying…
Again, I’ve just not the time right now to put into trying to exactly match your reference image, but I think this should demonstrate a workflow in Affinity Photo, both on desktop and Affinity Photo for iPad which will work for your use case.
Hope this helps!