Realtime Caustics in TouchDesigner with Easy GLSL

Caustics form from light refracted through a transparent medium (like the pretty patterns that form on the bottom of a swimming pool). This tutorial will outline the physics involved and show you how to create this effect in TouchDesigner using only a handful of lines of GLSL code.

Resources:
Ray / Plane intersection: https://www.scratchapixel.com/lessons/3d-basic-rendering/minimal-ray-tracer-rendering-simple-shapes/ray-plane-and-ray-disk-intersection.html

Caustics in Houdini: https://www.youtube.com/watch?v=GPYlgxMaMQs