Your sample is not a sculpture. It's actors, in make up, in front of a camera. There may have been some post processing. However I'd wager that 80-90% of the work is actually in the photography and not in software. People do still take photographs. Not everything is created in software.
If you want something even close to similar you'll need ninja-style 3D modeling skills and then great texture creations for surfaces.
You could spend a huge amount of time on something like this with just a raster image editor and never match what the camera does with real life and makeup. However, if you've got great photo-realism painting skills you may be able to pull it off. As for "how to paint photo-realism" I wouldn't know where to begin explaining.