At the time, Kostas Anagnostou @KostasAAA had experimented with getting hybrid Ray Tracing running on lower-end GPUs. I was talking to him because he was supposed to write an article for GPU Zen 2 about a culling system. I asked him if he would be interested in integrating his experiments in the Confetti rendering framework The Forge, so that we can run them on more platforms like Linux (VLKN), macOS / iOS (Metal 2) and then the XBOX One. When he started working on this, he re-visited some of his former ideas and improved the performance substantially. He wrote a blog post here: Interplay of Light
Today a new release of The Forge came out that supported his approach to Hybrid Ray Traced Shadows. It is running on all platforms that The Forge supports and the iOS version is running astonishingly well.
We have reason to believe that when it comes to hybrid Ray Traced Shadows, at the moment it is better to not use a Ray Tracing API. When using DXR, we expect Hybrid Ray Traced Shadows to run on all hardware apart from the GeForce RTX with subpar performance. We expect our implementation when compared to a DXR version both running on a GeForce RTX, to perform admirably and most important practically useful in games.Here is a screenshot running on an iPhone 7 with the Sponza scene and iOS 11.4.1 (15G77). Resolution is 1334 x 750.
The next step is to develop a Hybrid Ray Traced Reflection approach.
The general hope is to make it possible to have Hybrid Ray Traced Shadows, Reflections, and Ambient Occlusion on all GPUs and on all platforms available.