I think raymarching is an extremely elegant way to make complex scenes fit into a tiny amount of space. These are my favourite articles on raymarching because it shows just how compact they can be - a single mathematical equation:
Edit: The description for the "bridge" scene is interesting: "This is a sketch really, but it never got completed, due to the lack of artistic appealing of the image." I don't know if it's his extreme humility, but I think it wouldn't be overexaggerating if I said it's one of the best scenes on that page.
One more crazy thing you can do with raymarching - smoothly twine any shape into any other shape. Take any two signed distance fields, say they're defined by the functions dist0(p) and dist1(p). Then you can do
dist(p, t) = (1-t)*dist0(p) + t*dist1(p)
T doesn't have to be time-based, it can be space-based, so you have a shape that's a cylinder on the bottom and a large sphere on top and here's a mushroom https://www.shadertoy.com/view/lsSXWc
Edit: I have a very strong feeling that in most cases the resulting function isn't a "proper" distance field, but you can still raymarch through it normally.
http://iquilezles.org/www/articles/distfunctions/distfunctio...
http://iquilezles.org/www/articles/raymarchingdf/raymarching...
Edit: The description for the "bridge" scene is interesting: "This is a sketch really, but it never got completed, due to the lack of artistic appealing of the image." I don't know if it's his extreme humility, but I think it wouldn't be overexaggerating if I said it's one of the best scenes on that page.