Water Caustic Raymarching - UE4 - WIP

Testing a Caustic Shader Using Raymarching System.
Adding a postprocess effect using Raymarching too for volumetric Effect.

Thank to a basic calcul to get the worldposition under the waterplane, I just need to check if the position of the next step will be under the ground. Thanks to this technique, I can create GodRay under the water wich stop before the Ground