This is a neat little shader effect.
One interesting thing it made me think about, though: Even though I know exactly how it's made and could, in theory, replicate it... in practice, I never could, because I would become obsessed with making it work for all shapes, not just spheres, and the over-scoping would prevent me from ever finishing it!
Recreated this waterfall shader I made back in 2019, and wrote a breakdown post~ 💧 https://www.cyanilux.com/tutorials/waterfall-shader-breakdown/
