If you’re interested in seeing how 3D math(s) are done, this article by ex Googler Andy Sloane is about a program he wrote called donut.c. The name is doubly appropriate as not only is the source code shaped like a Donut (doughnut for us Brits), when run on Linux, it outputs an animated 3D donut. This was an attempt at obfuscated C back in 2006.
Now 15 years later he’s updated it to work without using the math library. Interesting is the explanation of how he did all the mathematics without using sin and cos directly. Also it includes a version that uses 10 bit integer arithmetic; no floats at all. If you’re interested in understanding how Donuts.c works, read this post from 2011.
I like articles like this- they’re a bit different and add to programming knowledge. and you can never get enough of that