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;...