Raymarching
https://iquilezles.org/www/articles/raymarchingdf/raymarchingdf.htm
https://iquilezles.org/www/articles/distfunctions/distfunctions.htm
At scale
https://youtu.be/jusWW2pPnA0?si=oWu_2peSA0WE7qB7
Physically-based rendering
https://pbr-book.org/4ed/Shapes/Basic_Shape_Interface