In this demonstration, Richard Piper gives a quick overview of physically based rendering using Marmoset's Basic Theory of Physically-Based Rendering as a reference and in doing so explains some of the most important concepts that you need to understand in order to get started in PBR. He then shows how to practically apply these concepts within Substance Painter to get the results you need on your assets.
from: Eat 3D:
PBR Practical Workflow from Eat 3D on Vimeo.