Book Image

OpenGL 4 Shading Language Cookbook, Second Edition - Second Edition

By : Wolff, David A Wolff
Book Image

OpenGL 4 Shading Language Cookbook, Second Edition - Second Edition

By: Wolff, David A Wolff

Overview of this book

OpenGL Shading Language (GLSL) is a programming language used for customizing parts of the OpenGL graphics pipeline that were formerly fixed-function, and are executed directly on the GPU. It provides programmers with unprecedented flexibility for implementing effects and optimizations utilizing the power of modern GPUs. With Version 4, the language has been further refined to provide programmers with greater power and flexibility, with new stages such as tessellation and compute. OpenGL 4 Shading Language Cookbook provides easy-to-follow examples that first walk you through the theory and background behind each technique, and then go on to provide and explain the GLSL and OpenGL code needed to implement it. Beginner level through to advanced techniques are presented including topics such as texturing, screen-space techniques, lighting, shading, tessellation shaders, geometry shaders, compute shaders, and shadows. OpenGL Shading Language 4 Cookbook is a practical guide that takes you from the fundamentals of programming with modern GLSL and OpenGL, through to advanced techniques. The recipes build upon each other and take you quickly from novice to advanced level code. You'll see essential lighting and shading techniques; examples that demonstrate how to make use of textures for a wide variety of effects and as part of other techniques; examples of screen-space techniques including HDR rendering, bloom, and blur; shadowing techniques; tessellation, geometry, and compute shaders; how to use noise effectively; and animation with particle systems. OpenGL Shading Language 4 Cookbook 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 (12 chapters)
11
Index

Introduction


It's easy to use shaders to create a smooth-looking surface, but that is not always the desired goal. If we want to create realistic-looking objects, we need to simulate the imperfections of real surfaces. That includes things such as scratches, rust, dents, and erosion. It is somewhat surprising how challenging it can be to make surfaces look like they have really been subjected to these natural processes. Similarly, we sometimes want to represent natural surfaces such as wood grain or natural phenomena such as clouds to be as realistic as possible without giving the impression of being synthetic or exhibiting a repetitive pattern or structure.

Most effects or patterns in nature exhibit a certain degree of randomness and non-linearity. Therefore, you might imagine that we could generate them by simply using random data. However, random data such as the kind that is generated from a pseudorandom-number generator is not very useful in computer graphics. There are two main reasons...