# NVRHI

**Repository Path**: thecasttim/NVRHI

## Basic Information

- **Project Name**: NVRHI
- **Description**: No description available
- **Primary Language**: Unknown
- **License**: MIT
- **Default Branch**: main
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2025-04-15
- **Last Updated**: 2025-04-15

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# NVRHI

[![Build Status](https://github.com/NVIDIA-RTX/NVRHI/actions/workflows/build.yml/badge.svg)](https://github.com/NVIDIA-RTX/NVRHI/actions/workflows/build.yml)

## Introduction

NVRHI (**NV**IDIA **R**endering **H**ardware **I**nterface) is a library that implements a common abstraction layer over multiple graphics APIs (GAPIs): Direct3D 11, Direct3D 12, and Vulkan 1.2. It works on Windows (x64 only) and Linux (x64 and ARM64).

Key features:

- Automatic tracking of resource states and barrier placement (optional).
- Automatic tracking of resource usage and lifetime, deferred and safe resource destruction.
- Convenient and efficient resource binding model with little runtime overhead.
- Easy direct interaction with the underlying GAPI when necessary.
- Easy portability of the rendering code between the supported GAPIs.
- Hidden sub-allocation of upload buffers and versioning of constant buffers.
- Parallel command list recording and multi-queue rendering.
- Supports all types of pipelines: Graphics, Compute, Ray Tracing, and Meshlet.
- Validation layer and resource reflection for easy debugging.

NVRHI is used in several NVIDIA SDKs:

- [Adaptive and Variable-Rate Shading SDK](https://github.com/NVIDIAGameWorks/nas-sample)
- [Donut Framework](https://github.com/NVIDIA-RTX/Donut) and its [Samples](https://github.com/NVIDIA-RTX/Donut-Samples)
- [Opacity Micro-Map SDK](https://github.com/NVIDIAGameWorks/Opacity-MicroMap-SDK)
- [Path Tracing SDK](https://github.com/NVIDIAGameWorks/Path-Tracing-SDK)
- [RTXDI SDK](https://github.com/NVIDIAGameWorks/RTXDI)

Notable third-party projects using NVRHI:

- [RBDoom3-BFG](https://github.com/RobertBeckebans/RBDOOM-3-BFG)

Various early versions of NVRHI have been used in various projects created at NVIDIA, including:

- [Asteroids demo](https://developer.nvidia.com/blog/using-turing-mesh-shaders-nvidia-asteroids-demo)
- [DLSS SDK](https://developer.nvidia.com/dlss)
- [VRWorks](https://developer.nvidia.com/vrworks)
- [VXGI](https://developer.nvidia.com/vxgi)
- [WaveWorks](https://developer.nvidia.com/waveworks)

## Requirements

* Windows or Linux (x64 or ARM64)
* CMake 3.10
* A C++ 17 compiler (Visual Studio 2019, GCC 8 or Clang 6)
* Windows SDK version 10.0.22621.0 or later for DX12 support

## Building NVRHI

NVRHI can be configured to be used a set of static libraries in CMake-based projects, or as a single dynamic library.

To include NVRHI into a CMake project as static libraries:

1. Add this repository as a submodule.
2. Add a `add_subdirectory(nvrhi)` directive to the parent CMakeLists.txt.
3. Add dependencies to the necessary targets: 
	* `nvrhi` for the interface headers, common utilities, and validation;
	* `nvrhi_d3d11` for DX11 (enabled when `NVRHI_WITH_DX11` is `ON`);
	* `nvrhi_d3d12` for DX12 (enabled when `NVRHI_WITH_DX12` is `ON`); and
	* `nvrhi_vk` for Vulkan (enabled when `NVRHI_WITH_VULKAN` is `ON`).

To build NVRHI as a shared library (DLL or .so):

1. Clone this repository recursively (including submodules).
2. Generate the project with CMake:
	* Set the `NVRHI_BUILD_SHARED` variable to `ON`.
	* Make sure to set the target platform to a 64-bit one. 32-bit builds are not supported.
3. Build and install as normal.

## Using NVRHI in Applications

See the [programming guide](doc/ProgrammingGuide.md) and the [tutorial](doc/Tutorial.md).

## NVAPI Support

NVRHI includes optional support for certain DX11 and DX12 extensions available through the NVAPI library. The library is not distributed with NVRHI but is available separately [here](https://developer.nvidia.com/nvapi).

To enable NVAPI support, extract the NVAPI SDK into the `nvapi` subfolder of your main project and set the `NVRHI_WITH_NVAPI` CMake variable to `ON`.

The following extensions are supported:

- Opacity Micro-Maps (DX12, Ada+)
- Shader Execution Reordering on DX12 (DX12, Ada+)
- Single Pass Stereo (Pascal+)
- Fast Geometry Shader with optional coordinate swizzling (Maxwell+)
- Conservative Raster and other rasterizer features (Maxwell+)
- HLSL Extensions through a fake UAV slot (see [this blog post](https://developer.nvidia.com/unlocking-gpu-intrinsics-hlsl))

## RTXMU Integration

NVRHI includes an optional integration of the [RTXMU](https://github.com/NVIDIA-RTX/RTXMU) library. The library is included as a git submodule, and can be enabled with the `NVRHI_WITH_RTXMU` CMake variable.

When RTXMU integration is enabled, all bottom-level ray tracing acceleration structures (BLAS'es) are managed by that library. All built BLAS'es that have the `AllowCompaction` flag set are automatically compacted when `ICommandList::compactBottomLevelAccelStructs` method is called. No other configuration is necessary.

## License

NVRHI is licensed under the [MIT License](LICENSE.txt).