AMD, following the relaunch of its GPUOpen program with new tools and an expanded FidelityFX package, also released a new version of the AMD ProRender renderer, including an updated Radeon Rays 4.0 (formerly known as FireRays) ray tracing acceleration library.
Previously, Radeon Rays could only run through OpenCL on the CPU or GPU, which was a pretty severe limitation. Now that upcoming AMD RDNA2 accelerators have been confirmed to feature hardware ray tracing units, Radeon Rays 4.0 finally gets GPU-specific BVH optimizations along with support for low-level APIs: Microsoft DirectX 12, Khronos Vulkan, and Apple Metal. Now the technology is based on HIP (Heterogeneous-Compute Interface for Portability) - the AMD C++ parallel computing platform (equivalent to NVIDIA CUDA) - and does not support OpenCL.
The most annoying thing is that Radeon Rays 4.0 was released without open source, unlike previous versions of the technology. Following complaints from some users, AMD has decided to partially reverse its decision. ProRender Product Manager Brian Savery:
“We have reviewed this issue internally and will make the following changes: AMD will publish Radeon Rays 4.0 open source, however, some AMD technologies will be placed in external libraries distributed under the SLA. As noted In the awesome looking Unreal Engine 5 demo thread, we're committed to providing generic ray tracing libraries that aren't tied to one vendor. That's the whole point of Radeon Rays, and while it's a good idea to distribute libraries with a permissive license based on your feedback, we've decided to go ahead and open source. So please keep building cool stuff with Radeon Rays, and if you're the type of developer who needs access to the source right now, get in touch via the github page or GPUOpen. Sources for Radeon Rays 2.0 ».
This is definitely good news for those who want to use Radeon Rays, especially since AMD ProRender is now available with official and .
Source: 3dnews.ru