Second attempt at creating a ray traced lighting algorithm. Go into the project and press the run block to run. I recommend 25% size for best performance-size ratio. Next step would be to add proper collisions with different objects/medium, such as refraction/reflection over glass. In a different project I attempted to try simulating diffraction gratings - a lot harder than it seems. I'm not sure whether storing interactive object positions in a list would be the best way to go for ray collisions, in terms of calculations.
