Volumetric Materials and Voxel Sculpting
Combination of 3D Coat and Keyshot. Check out the short making-of video for the details of the image.
The photo pack used - https://www.fotoref.com/collections/urban/products/misty-coast
Thumbnail image was obviously the hardest thing to do.
A test render out of Keyshot. Check the video for the process!
3D Coat is instrumental for achieving shapes needed for the render at maximum speed.