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 the compute shader for cloth simulation


The compute shader is well-suited for harnessing the GPU for physical simulation. Cloth simulation is a prime example. In this recipe, we'll implement a simple particle-spring-based cloth simulation using the compute shader. The following is an image of the simulation of a cloth hanging by five pins (you'll have to imagine it animating):

A common way to represent cloth is with a particle-spring lattice. The cloth is composed of a 2D grid of point masses, each connected to its eight neighboring masses with idealized springs. The following diagram represents one of the point masses (center) connected to its neighboring masses. The lines represent the springs. The dark lines are the horizontal/vertical springs and the dashed lines are the diagonal springs:

The total force on a particle is the sum of the forces produced by the eight springs to which it is connected. The force for a single spring is given by the following equation:

K is the stiffness...