I found this book on the subject: http://www.amazon.com/Physically-Based-Rendering-Second-Edition/dp/0123750792
It was published in 2010, and I was wondering if this would be a good read to learn real-time implementations for use in games. To be honest, I'd like to learn more about it, and if this book provides a good introduction to the concepts of physically-based rendering algorithms, then I'm onboard! It doesn't have to reference any APIs, but I'd prioritize OpenGL if they go into specific implementations as I'm most familiar with that API.
EDIT: After more research, it looks like a 3rd edition of the book will be arriving next year (2015).
Edited by Vincent_M, Yesterday, 02:14 PM.