Microsoft is moving on to the next generation of its DirectX gaming APIs for Windows and Xbox. DirectX 12 Ultimate enables developers to unlock all of the hardware features on PC and in the Xbox Series X. This includes a number of methods for improving game visuals and performance.
DirectX 12 Ultimate is getting that name for a reason. Microsoft built this API in an attempt to bring together cutting-edge development and multiple generations of hardware. This is possible because DirectX 12 Ultimate maintains compatibility with older GPUs and consoles that won’t support all of its features. So developers can make games optimized for DirectX 12 Ultimate and its features, and those games will still work properly on hardware that wasn’t made for DirectX 12 Ultimate.
Microsoft thinks this will lead to a “virtuous cycle” where developers no longer hold back their support for hardware features. The company wants to break that cycle with this unifying graphics API.
“When Xbox Series X releases, there will already be many millions of DX12 Ultimate PC graphics cards in the world with the same feature set, catalyzing a rapid adoption of new features,” reads a Microsoft blog post. “And when Xbox Series X brings a wave of new console gamers, PC will likewise benefit from this vast surge of new DX12 Ultimate capable hardware.”
And let’s dive into those capabilities.
DirectX 12 Ultimate gets Raytracing 1.1
Microsoft already baked in support for ray tracing into DirectX 12, but now it is improving how that technology works. Ray tracing enables a GPU to simulate the behavior of light in a way that looks more realistic and is also less work for developers. But with Ultimate, Microsoft is giving back some more control to game creators.
With DirectX Raytracing 1.1, games can now call on light rays from the GPU without first pinging the CPU. This makes it more efficient for engines to spool up more ray tracing shaders as players move around an environment.
Developers can also choose to use inline ray tracing, which acts as an alternative to dynamic ray tracing. In the dynamic model, the ray tracing system calculates how the lighting works depending on materials and light sources. With inline ray tracing, artists can pick and choose how the ray tracing behaves. Microsoft notes that inline is useful for confined shadows.
“Scenarios with many complex shaders will run better with dynamic-shader-based ray tracing, as opposed to using massive inline ray tracing uber-shaders,” writes Microsoft. “Meanwhile, scenarios that have a minimal shading complexity and/or very few shaders will run better with inline ray tracing.”
Microsoft has once again worked with Nvidia to ensure that DirectX Raytracing 1.1 takes full advantage of RTX video cards.
Variable rate shading, mesh shaders, and sampler feedback
Microsoft has piled a lot more into DirectX 12 Ultimate than just better ray tracing. It’s also getting better variable rate shading. This is the process that enables a game to dynamically tune down the detail on certain parts of a single frame render. The idea is to spend less of a GPU’s power drawing the shadowy parts of a room when players can’t really see the details in that area anyway. This can significantly improve performance.
Mesh shaders represents a big improvement to the geometry pipeline. It enables the GPU to control how it manages the level-of-detail. Put simply, this enables the GPU to apply the same process across a group of shaders at the same time. According to Microsoft, this method is both more flexible and simpler than previous geometry tools.
Sampler feedback is a tool to reduce load times and stuttering by more efficiently loading in assets. It’s a method of determining which part of a texture a game would need in any given situation without having to actually sample that situation.
“This information can then be fed back into the game’s asset streaming system, allowing it to make more intelligent, precise decisions about what data to stream in next,” reads Microsoft’s blog post. “In conjunction with the D3D12 tiled resources feature, this allows games to render larger, more detailed textures while using less video memory.”
Finally, sampler feedback also enables another feature called texture-space shading. This enables a developer to calculate light for a texture without actually having to render it.
What DirectX 12 Ultimate means for gamers
DirectX 12 Ultimate is a complicated graphics API, but it should lead to games that look better and run quicker over time. We will see if Microsoft is correct about quicker adoption of its features due to its compatibility across console and PC.
Microsoft didn’t say when it’s releasing DirectX 12 Ultimate, but it’s a big part of the Xbox Series X. So expect it to begin rolling out before this holiday. And then expect games to begin supporting it so after.