All the information you need was given to you here
You just need to read, try it, and understand it.
You aren’t “stating facts” when you say stuff like “I totally get that each Function has an IN & OUT pins but the whole point of making a function is so that you dont have to keep remaking the same parameters again and again”
You are assuming the inner workings of a system based on what YOU think it should work like… That’s not really going to help you move forward with your project.
Not to mention what you wrote is completely illogical.
First you state that you understand that a function is used to avoid re-making parameters over and over, but all the while you have been complaining about the fact that the parameters aren’t different when you use the same function…
Anyway, let’s move on from that. Come back with actual questions.
A global material function as described in post 4 will look something like this:
