All done in Excel, using only formulae with the only use of macros made for the inputting of key commands (e.g. wasd etc) and to run the animated camera. The video is sped up somewhat over what is achievable in the model (in particular, the final segment is obviously sped up by a lot). Don't forget, this is Excel! However, on my fairly old PC it updates once every 2 seconds, so isn't too bad considering! The model can be found here: https://github.com/s0lly/Raytracer-In-Excel Hope you enjoy! Acknowledgements: This model was inspired by "The Ray Tracer Challenge" book by Jamis Buck - a brilliant read! Not all the features of that book are included, of course - Excel can only handle so much!! Music by Eric Skiff, song "All of Us" for the intro and "09 Come and Find Me - B mix" for the main sequence. (Available at http://EricSkiff.com/music)