Thanks, I'll have to look even more into OSL (vs. GSL or RSL). I would hardly use the word 'worthless' just because RIS mode was introduced last year. The basics of what the prodecurally generated textures book taught me back then, still apply. Geometry, math, building up patterns in software, etc... Not to mention, the basis of such shaders just need to be translated just as GSL can be relatively simple to translate into OSL as the videos by Thomas Dinges show: https://www.youtube.com/watch?v=4LQXjIDWtz0