Working With Ray Traced Water Caustics in DXR

NVIDIA’s Holger Gruen enjoys snorkeling, a useful past-time when your day job includes figuring out how to help game developers get the most out of ray-traced water caustics in DXR. His observation of how light actually behaves underwater informed his approach to creating convincing simulations of aquatic environments.

Ray Traced Water Caustics with DXR, Holger’s full GDC19 presentation on the topic, can be found here. The talk explains how DXR Raytracing can help to overcome the quality and performance constraints that are inherent to caustics rendering methods used by most game engines. Viewers will learn how to create volumetric caustics, including volumetric shadows.

Below is a 5-minute excerpt from the talk. Holger explains how water caustics are created, and how ray tracing allows developers to interact with water caustics in unique ways. Why focus on ray tracing solutions instead of using traditional rasterization techniques? “Rasterization is only great at doing visibility from one point of view,” explains Holger. “That’s not what you need to simulate real-world water caustics, because you have to find out what you can see from an arbitrary point of view on the water surface, along any set of directions.”

hThe full talk is available here. An NVIDIA Developer Zone membership is required to access this content; registration is free, and it takes less than one minute to complete.