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

Rendering to a texture


Sometimes, it makes sense to generate textures on the fly during the execution of the program. The texture could be a pattern that is generated from some internal algorithm (a so-called procedural texture), or it could be that the texture is meant to represent another portion of the scene.

An example of the latter case might be a video screen where one can see another part of the world, perhaps via a security camera in another room. The video screen could be constantly updated as objects move around in the other room, by re-rendering the view from the security camera to the texture that is applied to the video screen!

In the following image, the texture appearing on the cube was generated by rendering the cow to an internal texture and then applying that texture to the faces of the cube:

In OpenGL, rendering directly to textures has been greatly simplified by the introduction of framebuffer objects (FBOs). We can create a separate rendering target buffer (the FBO), attach...