This project attempted to create an efficient method of generating rainbows projected through a prism without using photon mapping. Written from scratch in C# with no graphics libraries, I learned a lot about ray tracing processes during development. The basic ray tracer creates multiple rays per pixel that transmit through and reflect off of geometry in the scene. It can load in geometry from files, and uses a simple KD Tree implementation for optimization purposes.The main challenges of this project were representing the full spectrum of light and calculating the diffraction of light through the prism.

Instead of a basic RGB color value, each ray has a component for each wavelength of light. Each wavelength was associated with an RGB value according to the Mihai-Strajescu approximation. When rays encounter a refractive surface each wavelength splits off and is traced separately. This diffraction creates the rainbow effect on the spheres as observed in the image to the right.