If you want the other extreme, these days you can do real-time raytracing entirely in an OpenGL shader: https://www.shadertoy.com/view/XdfXDB https://www.shade

If you want the other extreme, these days you can do real-time raytracing entirely in an OpenGL shader: https://www.shadertoy.com/view/XdfXDB https://www.shadertoy.com/view/XdfXDB (There's no geometry in that scene --- the shader is run for each pixel independently!)