https://wccftech.com/nvidia-reveals-dxr-indie-spotlight-winners-tech-demos-available-for-download/

DXR, or DirectX Ray Tracing, is the API Microsoft announced at the Game Developers Conference 2018. A compatible extension to the existing DirectX 12 API, DXR was publicly released with the October 2018 Windows 10 update.

A few months ago, on the first anniversary of the DXR announcement, NVIDIA partnered with Epic and Microsoft for an Indie Spotlight contest. Participants were asked to create tech demos using Microsoft’s DXR and Epic’s Unreal Engine 4.22 which featured ray traced effects like reflections, shadows and ambient occlusion.