Signed distance functions in 46 lines of Python

Signed distance functions are a really cool method of 3D rendering! But they unfortunately have a reputation for being difficult to understand. It makes sense why—they usually get shown off in beautiful, but complicated ShaderToy examples written in GLSL, an unfamiliar language for most programmers1. But at their core, SDFs are a really simple idea. I'm going to prove that by walking you through a