Now that Microsoft and Sony have talked about their upcoming consoles in the light of day, the cat is out of the bag: AMD has its own raytracing solution. That’s hardly a surprise, but it’s official now. This week, Microsoft officially unveiled its ray tracing-focused update to the DirectX framework, DirectX 12 Ultimate, with some help from both AMD and Nvidia.
DirectX 12 Ultimate makes a whole host of new options available to developers. Streaming engines can more efficiently load new raytracing shaders as a player moves around the world, for example. Inline raytracing gives developers control over how their game handles raytracing. The overall raytracing scheduler can handle the work in big, detailed scenes, while the developer can take control of it in smaller scenes for more efficient application of the tech.
Variable Rate Shading allows developers to decide where to focus rendering detail. For example, in a racing game, you’ll want to focus full rendering power on the vehicle, while blurry scenery can render at decreased, but generally imperceptible detail.
Mesh Shaders sound really interesting. The developer can dynamically adjust the detail of the mesh behind the texture to better fit the needs of the scene the player is in. Nvidia has an asteroids demo that shows off how the system dynamically adjusts the meshes to keep the game looking good without crushing the CPU.
Finally, Sampler Feedback reminds me a lot of video rendering and compression. For example, if an item in the scene isn’t moving, that object’s lighting and other properties don’t need to be updated as often–but we won’t see the difference. In short, it uses visible visual data to predict things like shading instead of having to recompute them each time.
Nvidia and AMD on DirectX 12 Ultimate
Nvidia has a great video that goes over each of these concepts in some detail and is worth watching on its own:
Games written on DX12U will still run on hardware that doesn’t (or doesn’t yet) support DX12U; the hardware just won’t take advantage of these features. In other words, compatibility is not a concern according to Microsoft. Nvidia says that all RTX cards will support DX12U. Similarly, it stands to reason that AMD’s upcoming cards will do the same.
Speaking of AMD, AMD showed off its first big raytracing demo. It’s another robot walking around reflecting stuff, but it gets the job done. It proves that RDNA2 is capable of ray tracing.
The tech is only available on Xbox Series X and Windows. With the PlayStation 5 also using AMD RDNA2 hardware, it seems like porting should be fairly straightforward all the same.