Progress with Shaders - Step into Maths
The two pendulum panels on the left are experiments with raycasting. The rightmost sphere panel and the ocean background are raymarching.
Big thanks to iq and frankenburgh at shadertoy.
https://www.shadertoy.com/view/4sXGRM
iq demonstrates how to do this live at:
http://www.iquilezles.org/live/index.htm
I rewrote pretty much the same thing in order to get a handle on fragment shaders, but then tried sending the engine's camera coordinates and world coordinates for the panel through to the shader. Now you can step into math land and take a look around!