I’m new to Unreal Engine but I want to learn how to use the Material Editor, I watched some YouTube tutorials but the guys are horribly slow for me, and I decided to watch Unreal Engine reference and I got nothing, so I come here with hope that somebody could tell a place that works as manual for Unreal Engine material editor 
Btw, sorry if I picked the wrong category.
Great place to start with that stuff is the “content examples” project, that you’ll find in the “epic Games” Launcher… Under “learning” ue… Its free and you’ll find Lots of examples in it to start with and get Inspiration and see how the basics work, a lot to learn there and to explore how things “can be done”,… There are "“Showcase Levels” for Materials, advanced materials (and other Things, like blueprints, particle fx and many more) And besides that, yeah… Youtube 🤷:grimacing:
Cheers P.
Just found that Unreal Engine has an documentation about what most expressions do but I couldn’t find it until now Material Expression Reference | Unreal Engine Documentation but the main problem is that there aren’t all the expressions and there is a huge lack of them so I was wondering where I could find explanation for these that aren’t documentated
In CPP inside the engine source.
Or by putting the function in the material editor and double clicking it to open up and see what it does.
For some things this is necessary - the functions will look blue like your own custom material functions.
For other things, the source is somewhat commented within reason.
Best way to learn materials is to literally play with them.
Set some crazy goal, and poke at it until you get it right.
Possibly the best thing you can start with, water and grstner waves.