Building a Ray-Tracing 3D Renderer from Scratch

Ray tracing was my introduction to CS-like "real" programming, i.e. not just typing stuff in[1], but actually sitting down and thinking about the math of the problem[2]. I remember being super-excited (at 14-or-so yrs old) at being able to have my Turbo Pascal program draw a 640x480 grayscale(!) plane+sphere image on my monochrome VGA screen... which was the style at the time; the VGA card having been bought by me via pocket money and the screen having been bought by my parents. (Which is just another way of saying they bought both.)

Ray Tracing offers a remarkably big payoff for very little code. It does require a little algebra for line+(plane/sphere) intersections and such, but that's stuff you can easily look up these days.

[1] Yeah, I'm old. We had "codes" (typically heavily compressed/obfuscated) in these things called computer "magazines" that you would type in and see what happened.

[2] There's always math. Even if you're doing CRUD, there's probably math behind it: Form validation is a certain type of math, etc.

Writing a toy ray tracer is something that I'd recommend to everyone who's interesting in becoming a better programmer. Once you get deep enough into it you'll encounter so many interesting problems (e.g. data structures, software architecture, some linear algebra, etc.) to hone your skills on. It's almost up there with "write your own compiler" as a learning experience in my opinion and you get the added benefit of creating some pretty pictures in the process.

Ray tracing is great, metropolis flavour particularly. But you need an artistic sense to create complex and rewarding scene geometry, whether it's static or animated. I spent years obsessing over CS when the experience that actually drew me into the graphics field in the first place must have been the result of someone's artistic judgement, passed through a conceptually very simple bit of software (this is the 90s I'm talking about) which really just projected geometry into the screen.

(Oliver Deussen's work on rendering plants and other natural phenomena is an example of the kind of CS technique necessary to create geometry for any rendering process.)

I wrote a similar program in plain Java + Swing (and no other libraries) years ago, which I dumped on GitHub here (there are a few screenshots): https://github.com/idolize/ray-tracer

I love ray tracing. A small amount of code generates magical looking images. More advanced methods have a really pleasing mix of geometry, probability, data structures/algorithms, and low-level optimization.