Book Image

OpenGL 4 Shading Language Cookbook - Third Edition

By : David Wolff
Book Image

OpenGL 4 Shading Language Cookbook - Third Edition

By: David Wolff

Overview of this book

OpenGL 4 Shading Language Cookbook, Third Edition provides easy-to-follow recipes that first walk you through the theory and background behind each technique, and then proceed to showcase and explain the GLSL and OpenGL code needed to implement them. The book begins by familiarizing you with beginner-level topics such as compiling and linking shader programs, saving and loading shader binaries (including SPIR-V), and using an OpenGL function loader library. We then proceed to cover basic lighting and shading effects. After that, you'll learn to use textures, produce shadows, and use geometry and tessellation shaders. Topics such as particle systems, screen-space ambient occlusion, deferred rendering, depth-based tessellation, and physically based rendering will help you tackle advanced topics. OpenGL 4 Shading Language Cookbook, Third Edition also covers advanced topics such as shadow techniques (including the two of the most common techniques: shadow maps and shadow volumes). You will learn how to use noise in shaders and how to use compute shaders. The book provides examples of modern shading techniques that can be used as a starting point for programmers to expand upon to produce modern, interactive, 3D computer-graphics applications.
Table of Contents (17 chapters)
Title Page
Packt Upsell
Contributors
Preface
Index

A physically-based reflection model


Physically-based rendering or PBR is an umbrella term that encompasses tools and techniques that make use of physically-based models of light and reflection. The term itself is somewhat loosely defined, but can generally be described as a shading/reflection model that tries to model the physics of light interacting with matter as accurately as possible. The term may mean slightly different things to different people, but for our purposes, we are interested primarily in how it differs from the Phong and the Blinn-Phong reflection models.

The Blinn-Phong model is an empirical model of reflection based on observation. A PBR model could also be considered an empirical model, but in general, it is more detailed and accurate with regards to the physics of the interaction being represented. The Blinn-Phong model uses a few parameters which are not physically based but produce effective results. For example, separating the light intensity into three (or two) separate...