Microsoft announced the DirectX 12 Ultimate API last year which would enable games to use several modern DirectX 12 graphics features like DirectX Raytracing (DXR), Variable Rate Shading (VRS), Mesh Shaders, and Sampler Feedback. However, DX12 Ultimate has a major limitation. The API is only supported by Windows PCs with the May 2020 update or newer, which was severely hampering the rate of adoption of the modern API as developers didn't want to code games for fewer people.
As a solution to this, Microsoft today has released the new DirectX 12 Agility SDK. This new SDK, unlike DX12 Ultimate, is compatible with PCs still using anything as back as the November 2019 update.Essentially, it will make DirectX 12 Ultimate features backwards compatible with older OS versions. According to Microsoft, developers are pleased with this as it should immensely help with the adoption of the DirectX 12 Ultimate API and its accompanying features as there are naturally a lot more users on older build versions.
Here's what Nick Penwarden, Vice President, Engineering, Epic Games, has said:
Our collaboration with Microsoft on the DirectX 12 Agility SDK enables us to easily implement forward-looking Unreal Engine features, and the new distribution model makes them quickly available to our developer and player communities.
The Agility SDK is fully compatible with DirectX 12 Ultimate and HLSL Shader Model 6.6. The Shader Model 6.6 has been announced today and brings several modern shader compiling features which are listed below:
New Atomic Operations,
Helper Lane Detection,
Quad-based derivative operations,
Pack and Unpack Intrinsics,
Raytracing Payload Access Qualifiers.
For developers and users interested in or looking to try Agility SDK, you can find more details about it in the official blog here.