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 volume rendering using splatting


In this recipe, we will implement splatting on the GPU. The splatting algorithm converts the voxel representation into splats by convolving them with a Gaussian kernel. The Gaussian smoothing kernel reduces high frequencies and smoothes out edges giving a smoothed rendered output.

Getting ready

The code for this recipe is in the Chapter7/Splatting directory.

How to do it…

Let us start this recipe by following these simple steps:

  1. Load the 3D volume data and store it into an array.

    std::ifstream infile(filename.c_str(), std::ios_base::binary); 
    if(infile.good()) {
    pVolume = new GLubyte[XDIM*YDIM*ZDIM];
    infile.read(reinterpret_cast<char*>(pVolume), XDIM*YDIM*ZDIM*sizeof(GLubyte));
    infile.close();
    return true;
    } else {
    return false;
    }
  2. Depending on the sampling box size, run three loops to iterate through the entire volume voxel by voxel.

    vertices.clear(); 
    int dx = XDIM/X_SAMPLING_DIST;
    int dy = YDIM/Y_SAMPLING_DIST;
    int dz = ZDIM/Z_SAMPLING_DIST;...