Here's another cool lighting experiment with Unreal lighting and water caustics by Patrick Dyer. The artist used RTX Reflections, Shadows, GI, and Sky-lighting. The scene is powered by a lot of ray-traced rays and it's running at about 24 fps on an RTX 2070. "There are two forms of simple caustics being generated in the scene, one from a light function projected by a set of spotlights, and the other an emissive function on the inline pool material," wrote the artist. You can learn more here.