This diamond is light by multiple light sources. Each ray of light is absorbed, reflected, and refracted in varying proportions, and anti-aliasing ensures that edges are smooth.

Enhancements#

This iteration of the 3D ray-tracing graphics engine (see previous) adds the following features:

• Multiprocessing
  • Ray-tracing is inherently parallelisable: you have millions of rays that are all independent of one another. We achieve an “easy” 5-10x performance increase by using as many cpu cores as possible.
• Anti-aliasing
  • I experimented with a few different algorithms, and found that multisample anti-aliasing worked very well. This involves firing multiple rays for each pixel and averaging out the result. I clawed back some performance by detecting when anti-aliasing was required (severe edges), and only subsampling for affected pixels.
• Real-time rendering
  • I created a new window-mode so that the user can control the camera in real-time.
• Compound shapes
  • I added some functions for building up complex shapes from primitives. Below you can see how I created a diamond from lots of triangles.
• Split rays
  • Light doesn’t choose between absorption, reflection, and refraction. In reality it will do all three.

This diamond is made from lots of triangles, and has an accurate refractive index. With anti-aliasing turned on, the edges of this diamond become buttery smooth.