Overview
Physically Based Rendering: From Theory to Implementation
Comprehensive reference on physically based rendering techniques
Learn OpenGL: Shadow Mapping
Learn OpenGL's tutorial on physically based rendering
Physically Based Rendering in Filament
Google's documentation on the PBR system on their Filament renderer on Android. Best in class documentation about high performance PBR lighting shaders
Robust Monte Carlo Methods for Light Transport Simulation
the Academy Award-winning Ph.D. thesis by Eric Veach. It starts from bidirectional light transport algorithms and introduces multiple importance sampling and Metropolis light transport
Advanced Global Illumination
An advanced book focused on light transport theory for global illumination.
Basics of physically-based rendering (Siggraph 2012)
This tutorial will cover the basics of physically-based rendering such as reflection models (BRDF), volume scattering (phase functions), optical phenomena (dispersion and polarization)