NVIDIA RENDER INTERFACE (NRI)

NRI is a low-level abstract render interface which currently supports three backends: D3D11, D3D12 and Vulkan (VK). NRI has been designed to support all (at least major) low level features of D3D12 and VK APIs, but at the same time to simplify usage and reduce the amount of code needed (especially compared with VK). NRI is written in C++, but supports both C++ and C interfaces.

Goals:

• generalization of D3D12 (spec) and VK (spec) GAPIs
• providing access to low-level features of modern GAPIs
• low overhead
• explicitness
• D3D11 (spec) support (as much as possible)

Non-goals:

• high level RHI
• exposing entities not existing in GAPIs
• D3D11-like abstraction level
• hidden management of any kind

Key features:

• C++ and C compatible interfaces
• generalized common denominator for D3D12, VK and D3D11 GAPIs
• low overhead
• ray tracing support
• mesh shaders support
• D3D12 Ultimate features support, including enhanced barriers
• VK printf support
• validation layers (GAPI- and NRI- provided)
• default D3D11 behavior is changed to match D3D12/VK using NVAPI or AMD AGS libraries, where applicable
• supporting as much as possible VK-enabled platforms: Windows, Linux, MacOS, Android

NRI is used in:

• NRI samples
• NRD Sample

BUILD INSTRUCTIONS

• Install Cmake 3.15+
• Install on
  • Windows: latest WindowsSDK and VulkanSDK
  • Linux (x86-64): latest VulkanSDK and optional libx11-dev and libwayland-dev
  • Linux (aarch64): optional libx11-dev and libwayland-dev
• Build (variant 1) - using Git and CMake explicitly
  • Clone project and init submodules
  • Generate and build the project using CMake
• Build (variant 2) - by running scripts:
  • Run 1-Deploy
  • Run 2-Build

Notes:

• Xlib and Wayland can be both enabled
• Minimal supported client is Windows 8.1+. Windows 7 support requires minimal effort and can be added by request

CMAKE OPTIONS

• NRI_STATIC_LIBRARY - build NRI as a static library (off by default)
• NRI_ENABLE_VK_SUPPORT - enable VULKAN backend (on by default)
• NRI_ENABLE_D3D11_SUPPORT - enable D3D11 backend (on by default on Windows)
• NRI_ENABLE_D3D12_SUPPORT - enable D3D12 backend (on by default on Windows)

VK only:

• NRI_ENABLE_XLIB_SUPPORT - enable Xlib support (on by default)
• NRI_ENABLE_WAYLAND_SUPPORT - enable Wayland support (on by default)

D3D12 only:

• NRI_ENABLE_AGILITY_SDK_SUPPORT - enable Agility SDK (off by default)
• NRI_AGILITY_SDK_PATH - path to a directory containing Agility SDK: contents of .nupkg/build/native/ (C:/AgilitySDK by default)
• NRI_AGILITY_SDK_VERSION - Agility SDK version (711 or newer)
• NRI_AGILITY_SDK_DIR - directory where Agility SDK binaries will be copied to relative to CMAKE_RUNTIME_OUTPUT_DIRECTORY (AgilitySDK by default)

AGILITY SDK

IMPORTANT: NRI features requiring Agility SDK are marked as // TODO: D3D12 requires Agility SDK with version specification.

Overview and Download sections can be found here.

D3D12 backend uses Agility SDK to get access to most recent D3D12 features. As soon as these features become available in the OS, installation of Agility SDK will be deprecated.

Installation steps:

• download Agility SDK package
  • preview versions require enabling Developer Mode in Windows
• rename .nupkg into .zip
• extract contents of .nupkg/build/native into NRI_AGILITY_SDK_PATH folder
  • can be located anywhere
• set NRI_AGILITY_SDK_DIR to a path, where bin folder needs to be copied
  • most likely closer to the executable
• set NRI_AGILITY_SDK_VERSION to the version of the package
• enable NRI_ENABLE_AGILITY_SDK_SUPPORT
• re-deploy project
• include auto-generated NRIAgilitySDK.h header in the code of your executable, using NRI

SAMPLES OVERVIEW

NRI samples can be found here.

Samples:

• DeviceInfo - queries and prints out information about device groups in the system
• Clear - minimal example of rendering using framebuffer clears only
• CTest - very simple example of C interface usage
• Triangle - simple textured triangle rendering
• SceneViewer - loading & rendering of meshes with materials
• Readback - getting data from the GPU back to the CPU
• AsyncCompute - demonstrates parallel execution of graphic and compute workloads
• MultiThreading - shows advantages of multi-threaded command buffer recording
• MultiGPU - multi GPU example
• RayTracingTriangle - simple triangle rendeing through ray tracing
• RayTracingBoxes - a more advanced ray tracing example with many BLASes in TLAS
• Wrapper - shows how to wrap native D3D11/D3D12/VK objects into NRI entities
• Resize - demonstrates window resize

LICENSE

NRI is licensed under the MIT License. This project includes NVAPI software. All uses of NVAPI software are governed by the license terms specified here.