This is a great resource! For those interested in a very quick and direct intro to writing code for ray tracing, something I think supplements Scratchapixel nicely, you might want to also check out "Ray Tracing in One Weekend". http://in1weekend.blogspot.com/2016/01/ray-tracing-in-one-we.... It's a $3 ebook on Amazon, but the blog post has lots of free resources including the complete code for the small ray tracer developed in the book. Written Peter Shirley, by a graphics prof. friend of mine, well known in graphics / ray tracing / global illumination circles.
