You have now hit on my #1 missing gap in UE4 and I know it seems minor, but for some reason translucency and glass-like means a lot to me so HERE WE GO.
UE4’s deferred rendering system rendering the depth buffer (Z buffer) first means that all processing and calculations stop when it hits the glass and not the objects behind the glass or the objects reflecting against the glass. THEN it renders out colour, texture, metallic, etc etc etc. (that’s the G buffer and it doesn’t matter for my rant here).
So what then? To a computer glass is an object, which it is, and it is treated like anything else, but it’s not like anything else. But Unreal doesn’t know how to tell the difference between something that is there and semi-transparent and something that is (for all intents and purposes) opaque because it is rendering /depth first/. All you can tell it is there is something there, but glass is something that, to a computer, is kind of there.
The solution then, I guess, is to just look at all the garbage behind the glass because when you look through a window you look at all the garbage behind it and only slightly see that there is glass there and that. That’s probably what that tutorial did. I didn’t look at it, but 90% of glass tutorials make strange looking there/not there materials that look super duper transparent and add some dynamic spotlighting or something, but that’s unnatural because even when you don’t see the glass you see the glass. The issue here is that if the computer doesn’t see the glass, it is seeing nothing so it is displaying nothing and there is nothing which feels bizarre then the audience is put off.
So, I wish I had your answer and that I could give you glass because even understanding why it is such a difficult feat to accomplish for Epic, I am profoundly demanding and this is my biggest want for Unreal. Pretty glass.
/sigh Sorry, this is a hot button topic for me apparently. If you post some screenshots of your material and your BP, you may be able to get closer to what you want with the caveat that I don’t know if it’ll ever be perfect until Unreal updates their rendering possibilities.