The kitchen has several objects whose materials are simple to set up and will serve as a good introduction to the basics of PBR. Eevee's real-time rendering is based around controlling a limited set of variables that have the potential to replicate all of the physically possible materials in the entire world. Take any dirt, meteor, banana, or liquid in the universe, and you can map its properties from a value of 0 (0%) to a value of 1 (100%):
- Black to white colors (distributed over Red, Green, and Blue (RGB) pixels)
- Transparent to opaque
- Rough to smooth
- Dielectric to metallic
Nodes are a way to map those values. A value of 0 Roughness means not rough at all. A value of 1 Roughness means very rough. A value of 0 Transparency is completely opaque. A value of 1 Transparency is completely transparent. If you took a photograph, it has...