There is a rumor that AMD has been working on its own version of ray-tracing technology that could be incorporated into the red team's expected Navi 20 series. The same source speculates that this high-end lineup could challenge or even surpass the ray-tracing capabilities of Nvidia's GeForce RTX 2080 and RTX 2080 Ti graphics cards.
https://www.notebookcheck.net/Rumor-AMD-s-Navi-20-series-could-feature-ray-tracing-technology-that-would-challenge-Nvidia-s-RTX-lineup.415149.0.html
I sincerely hope they will not create fixed function HW for RT. It is wasted die space in too many places. GCN already is very good for RT workloads. They should write specialized compute shaders, but not go down the road Nvidia is going. RT is going to become the next Tessellation in graphics. The actual API will come and go, because better methods will come. You don't hear much of tessellation lately, and not because it has become a commonplace. It was superceded by more efficient compute shader implementations.
Pay attentions to this new updated that came out few days ago:
Looks like they will use FP16 for BVH, since Vega GPU's support 2:1 FP16 ~26TFLOPS.
Also BVH benefits from Fast HBM2 memory.
Quote*NEW* Vulkan®-based Radeon Rays 3.0 available now
Radeon™ Rays 3.0 Supports both AMD GPUs and CPUs as well as those of other vendors using Vulkan®
Features include GPU-accelerated Bounding Volume Hierarchy (BVH) and half-precision (FP16) computation support
Works across Windows® and Linux®