At GDC, Microsoft announced a new feature for DirectX 12: DirectX Raytracing (DXR). The new API offers hardware-accelerated raytracing to DirectX applications, ushering in a new era of games with more realistic lighting, shadows, and materials. One day, this technology could enable the kinds of photorealistic imagery that we've become accustomed to in Hollywood blockbusters.
[...] Because of the performance demands, Microsoft expects that DXR will be used, at least for the time being, to fill in some of the things that raytracing does very well and that rasterization doesn't: things like reflections and shadows. DXR should make these things look more realistic. We might also see simple, stylized games using raytracing exclusively.
The company says that it has been working on DXR for close to a year, and Nvidia in particular has plenty to say about the matter. Nvidia has its own raytracing engine designed for its Volta architecture (though currently, the only video card shipping with Volta is the Titan V, so the application of this is likely limited). When run on a Volta system, DXR applications will automatically use that engine.
In conjunction with Microsoft’s new DirectX Raytracing (DXR) API announcement, today NVIDIA is unveiling their RTX technology, providing ray tracing acceleration for Volta and later GPUs. Intended to enable real-time ray tracing for games and other applications, RTX is essentially NVIDIA's DXR backend implementation. For this NVIDIA is utilizing a mix of software and hardware – including new microarchitectural features – though the company is not disclosing further details.
(Score: 3, Informative) by mth on Tuesday March 20 2018, @03:45PM
Both DX12 and Vulkan were inspired by AMD's Mantle API. I much prefer Vulkan because it is cross-platform, but I don't think it's fair to say that DirectX is behind the times.
As far as I know, there is no specific support for ray tracing in any of those APIs. People have done ray tracing with existing graphics APIs, so I don't know how much of a difference a dedicated API makes: does it actually make things easier or faster, or is it just marketing?