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

Simulating fire with particles


To create an effect that roughly simulates fire, we only need to make a few changes to our basic particle system. Since fire is a substance that is only slightly affected by gravity, we don't worry about a downward gravitational acceleration. In fact, we'll actually use a slight upwards acceleration to make the particles spread out near the top of the flame. We'll also spread out the initial positions of the particles so that the base of the flame is not just a single point. Of course, we'll need to use a particle texture that has the red and orange colors associated with flame.

The following image shows an example of the running particle system:

The texture that was used for the particles looks like a light smudge of the flame's colors. It is not shown here because it would not be very visible in print.

Getting ready

Start with the basic particle system presented in the Creating a particle system using transform feedback recipe earlier in this chapter:

  1. Set the...