Microsoft has released the official version of DirectX 12 Agility SDK 1.619 and the preview version of 1.719, which include the new version of Shader Model 6.9 (SM 6.9) and two important updates of DXR 1.2 light tracing.Agility SDK is a way for Microsoft to push the new version of DX12 functions. There is no need to wait for Windows Update. Games can directly package the new version of the runtime and only require compatible GPU graphics card hardware and driver support.
DX12 Agility SDK 1.619 includes the new version of SM 6.9, which mainly upgrades the shader language and minimum functional requirements.
The common language used by developers to write GPU programs for DX is called HLSL, and SM is the "feature level" of HLSL shaders.
SM 6.9 highlights the new feature "Long Vector". With it, shaders can directly use vectors with more than 4 components and up to 1024 components, without the need for cumbersome packaging processing.
at the same time,Some features that were originally optional become required on hardware that supports SM 6.9,include:
Native 16-bit shader operations, Wave operations (communication within thread groups), and 64-bit integer operations.
The two important upgrades of DXR 1.2 light tracing are:
1. Opacity Micromaps
It has been available for a long time, but this time it is officially released, and the last part of HLSL-related interfaces are no longer marked as preview.
The new version mainly optimizes geometry with Alpha testing, such as fences, vegetation, and hollow textures. Such objects are usually very expensive in light tracing and are prone to expensive shader branches.
2. Shader Execution Reordering (SER)
It also ended the preview stage and became the official version.
SER allows the GPU to regroup similar light tasks so that they can be executed more coherently and improve light tracing efficiency.
In the new version, applications can query whether the GPU actually performs reordering, not just whether it is supported at the API level.
Different GPUs have very different support for DX12 feature levels. Basic SM 6.9 features such as long vectors and 16-bit floating point require: AMD RX 9000 series, NVIDIA RTX series, and Intel Arc B series.
Currently, only the NVIDIA RTX series can provide hardware support for light tracing opacity micromaps. The RTX 50/40 series supports hardware acceleration, and the RTX 30/20 series uses software simulation.
SER is supported by NVIDIA RTX 50/40 series and Intel Arc B series hardware. AMD RX 9000 series only supports API, but there is no actual reordering.
In addition, DX12 Agility SDK 1.719 also contains previews of a number of new features, namely:
1.Fence Barriers
Extended enhanced barriers allow the command buffer to signal and wait for barriers in the instruction stream, enabling more fine-grained synchronization.
2.VPblit 3DLUT
Open video processing hardware pipeline for tone mapping and 3D lookup table operations, offloading this work from the main 3D engine.
3. D3D12 Extensions mechanism
The official plug-in solution allows hardware manufacturers to provide experimental features before the functions enter the D3D12 core.
