I'm brand new to blender and am still working my way through beginner tutorials. I am now on one where I make a beer in a glass. I'm having so much trouble getting my glass to look like glass. I'm working in Blender 2.8 and this example is from 2.7x. https://youtu.be/Xbc3KMIOuKM?t=734 When I do what Andrew does (see link) my glass just looks like weirdly irredescent clay. If I wanted to do the equivalent in 2.8 - what exactly is that?