Ray Casting

For each pixel on the image plane, ray casting performs the following steps:

• Determine viewing ray through eye point and pixel on image plane
• Sample the viewing ray
  • from back to front
  • with step length 1 voxel
• Accumulate the optical effects for each step
  • Accumulated light intensity is decreased by absorption (exponentially with the sampled step length)
  • Accumulated light intensity is increased by emission (linearily with the sampled step length)