@RedDiamond 
Yep I use the fabulous free Online & very easy Gaugan 2 (from NVidia Lab)! :)  http://gaugan.org/gaugan2/
Any headaches! :) 
A very detailed process is here (sorry in French) ;)  (you can use any translaters)
 https://moiscript.weebly.com/gaugan.html
In resume you can use any image PNG or JPG but prefer PNG because you have "solid" colors 
and especially the 32 colors of Gaugan for a more precise control of materials!
 
You can draw directly with some primitive tools or even your own fingers!!! 
Or more easily and speedy with some images yet created!
 
I use the very funny free MagicaVoxel  http://ephtracy.github.io/index.html?page=mv_main
or the free Online Vervette  https://moiscript.weebly.com/vervette.html
for create any start PNG image! 
But you can use your favorite prog for create a 2D start image!
 
Have fun! 
here 2 seconds fingers! :)
  
Here a pure Moi Objects jpg image (on the left) can give you terrific variations (on the right) ! :) 
So of course an infinite worlds to explore!
  
And if you take the 2 images above (Moi + result)  + any text you will obtain an infinite fractal result!  
here with "Tropical beach" as text :)
  
or "green vegetation" as text...etc...
  
and all that in less of 3 Seconds!  
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