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
About the Author
About the Reviewers

Implementing volumetric lighting using the half-angle slicing

In this recipe, we will implement volumetric lighting using the half-angle slicing technique. Instead of slicing the volume perpendicular to the viewing direction, the slicing direction is set between the light and the view direction vectors. This enables us to simulate light absorption slice by slice.

Getting ready

The code for this recipe is in the Chapter7/HalfAngleSlicing directory. As the name suggests, this recipe will build up on the 3D texture slicing code.

How to do it…

Let us start this recipe by following these simple steps:

  1. Setup offscreen rendering using one FBO with two attachments: one for offscreen rendering of the light buffer and the other for offscreen rendering of the eye buffer.

    glGenFramebuffers(1, &lightFBOID); 
    glGenTextures (1, &lightBufferID);  
    glGenTextures (1, &eyeBufferID); 
    lightBufferID = CreateTexture(IMAGE_WIDTH, IMAGE_HEIGHT, GL_RGBA16F, GL_RGBA);