I remember this super helpful tutorial on PShader and shader 101, which I believe was either done by Andres Colubri, or by one of the newer kids on the block, going over how to set up your vertex an pixel shaders, and what to do with them. I’m now finding some 404s… is this going back up or any leads?
BTW. The first link is from GitHub, which should be safe to open, but I don’t know anything about who wrote the online tools in the second and third links (just found them online). So if they ask you for your credit card number, think about it twice