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

Creating a particle system using instanced meshes


To give more geometric detail to each particle in a particle system, we can draw entire meshes instead of single quads. Instanced rendering is a convenient and efficient way to draw several copies of a particular object. OpenGL provides support for instanced rendering through the functions glDrawArraysInstanced and glDrawElementsInstanced.

In this example, we'll modify the particle system introduced in the previous recipes. Rather than drawing single quads, we'll render a more complex object in the place of each particle. The following image shows an example where each particle is rendered as a shaded torus:

We covered the basics of instanced rendering in the previous recipes, so you may want to review those before reading this one. To draw full meshes, we'll use the same basic technique, with some minor changes.  

We'll also add another attribute to control the rotation of each particle so that each can independently spin at a random rotational...