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

Using gamma correction to improve image quality


It is common for many books about OpenGL and 3D graphics to somewhat neglect the subject of gamma correction. Lighting and shading calculations are performed, and the results are sent directly to the output buffer without modification. However, when we do this, we may produce results that don't quite end up looking the way we might expect. This may be due to the fact that computer monitors (both the old CRT and the newer LCD) have a non-linear response to pixel intensity. For example, without gamma correction, a grayscale value of 0.5 will not appear half as bright as a value of 1.0. Instead, it will appear to be darker than it should.

The lower curve in the following graph shows the response curves of a typical monitor (gamma of 2.2). The x axis is the intensity and the y axis is the perceived intensity. The dashed line represents a linear set of intensities. The upper curve represents gamma correction applied to linear values. The lower curve...