Someone suggested I look up dithering for shading and boy does this one have potential. I've read that normally this is done using a texture pattern but one place showed off a Matrix that replicates the same results, which makes this process lightweight.
Code wise, this is surprisingly very simple. The whole matrix technique if you really break it down and play with it can give you ideas of how to create pixel patterns that you can repeat in screen space or maybe even uv.
Code is free. Have at it, its a nice sample and def worth learning just on the ideas of pixel patterns only.
[ SHAMELESS PLUG ]
I have a patreon for anyone who would like to support my work. Everything I do I release as open source. With a enough support I can do this full time and make more stuff for people to use and learn from. https://www.patreon.com/sketchpunk