The PBR tutorial series on LearnOpenGL.com covers a lot of the concepts implemented here like physically based BRDFs and HDR lighting, if anyone is looking for more resources like this.
If like me you actually enjoy tech talk videos, "SIGGRAPH University - Introduction to Physically Based Shading in Theory and Practice" is great. PDF version is linked at the bottom of your learnopengl page. https://www.youtube.com/watch?v=j-A0mwsJRmk
https://learnopengl.com/PBR/Theory