Have a look at two beautiful experiments with RTX caustics in Unreal.
Young Jo Cho has recently shared a look at his experiments with RTX Caustics in Unreal Engine 4.25. Let's have a look.
Unfortunately, little is known about the artist's rig or the setup here, but you have to admit that the result in incredible. You can find the original post here.
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.