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

Steep parallax mapping with self shadowing


This recipe builds on the previous one, parallax mapping, so if you haven't already done so, you may want to review that recipe prior to reading this one.  

Steep parallax mapping is a technique, first published by Morgan McGuire and Max McGuire in 2005. It improves upon parallax mapping, producing much better results at the cost of more fragment shader work. Despite the additional cost, the algorithm is still well suited to real-time rendering on modern GPUs.  

The technique involves tracing the eye ray through the height map in discrete steps until a collision is found in order to more precisely determine the appropriate offset for the texture coordinate. Let's revisit the diagram from the previous recipe, but this time, we'll break up the height map into n discrete levels (indicated by the dashed lines):

As before, our goal is to offset the texture coordinates so that the surface is shaded based on the bump surface, not the true surface. The point...