A very nice little present for 3d artists, who want to do some character work, or just want to have fun with spheres, was created by Edward Godlach. He has recently published an ‘Iris Generator’, which works inside Substance Painter, Substance Designer (or Photoshop). Here’s how you do it.
A short instruction for SP:
A short instruction for PShop:
This little tool is not free, but you can grab it without paying if you just ask Edward nicely (just don’t spam him).