Book Image

OpenGL Development Cookbook

By : Muhammad Mobeen Movania
Book Image

OpenGL Development Cookbook

By: Muhammad Mobeen Movania

Overview of this book

OpenGL is the leading cross-language, multi-platform API used by masses of modern games and applications in a vast array of different sectors. Developing graphics with OpenGL lets you harness the increasing power of GPUs and really take your visuals to the next level. OpenGL Development Cookbook is your guide to graphical programming techniques to implement 3D mesh formats and skeletal animation to learn and understand OpenGL. OpenGL Development Cookbook introduces you to the modern OpenGL. Beginning with vertex-based deformations, common mesh formats, and skeletal animation with GPU skinning, and going on to demonstrate different shader stages in the graphics pipeline. OpenGL Development Cookbook focuses on providing you with practical examples on complex topics, such as variance shadow mapping, GPU-based paths, and ray tracing. By the end you will be familiar with the latest advanced GPU-based volume rendering techniques.
Table of Contents (15 chapters)
OpenGL Development Cookbook
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Implementing global illumination using spherical harmonics lighting


In this recipe, we will learn about implementing simple global illumination using spherical harmonics. Spherical harmonics is a class of methods that enable approximation of functions as a product of a set of coefficients with a set of basis functions. Rather than calculating the lighting contribution by evaluating the bi-directional reflectance distribution function (BRDF), this method uses special HDR/RGBE images that store the lighting information. The only attribute required for this method is the per-vertex normal. These are multiplied with the spherical harmonics coefficients that are extracted from the HDR/RGBE images.

The RGBE image format was invented by Greg Ward. These images store three bytes for the RGB value (that is, the red, green, and blue channel) and an additional byte which stores a shared exponent. This enables these files to have an extended range and precision of floating point values. For details...