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 GPU-based ray tracing

To this point, all of the recipes rendered 3D geometry using rasterization. In this recipe, we will implement another method for rendering geometry, which is called ray tracing. Simply put, ray tracing uses a probing ray from the camera position into the graphical scene. The intersections of this ray are obtained for each geometry. The good thing with this method is that only the visible objects are rendered.

The ray tracing algorithm can be given in pseudocode as follows:

For each pixel on screen
  Get the eye ray origin and direction using camera position
  For the amount of traces required
    Cast the ray into scene
    For each object in the scene
      Check eye ray for intersection 
      If intersection found
        Determine the hit point and surface normal 
        For each light source 
          Calculate diffuse and specular comp. at hit point
          Cast shadow ray from hit point to light 
        End For
        Darken diffuse component...