Falcor is a real-time rendering framework supporting DirectX 12. It aims to improve productivity of research and prototype projects.

Features include:

• Abstracting many common graphics operations, such as shader compilation, model loading, and scene rendering
• DirectX Raytracing abstraction
• Render Graph system
• Python scripting
• Common rendering effects such as shadows and post-processing effects
• Unbiased path tracer
• Integration of various RTX SDKs: DLSS, RTXGI, RTXDI, NRD

• Windows 10 version 20H2 (October 2020 Update) or newer, OS build revision .789 or newer
• Visual Studio 2019
• Windows 10 SDK (10.0.19041.0) for Windows 10, version 2004
• A GPU which supports DirectX Raytracing, such as the NVIDIA Titan V or GeForce RTX
• NVIDIA driver 466.11 or newer

Optional:

• Windows 10 Graphics Tools. To run DirectX 12 applications with the debug layer enabled, you must install this. There are two ways to install it:
  • Click the Windows button and type Optional Features, in the window that opens click Add a feature and select Graphics Tools.
  • Download an offline package from here. Choose a ZIP file that matches the OS version you are using (not the SDK version used for building Falcor). The ZIP includes a document which explains how to install the graphics tools.
• NVAPI, CUDA, OptiX (see below)

Falcor comes with 2 rendering backends: Native D3D12 and Slang GFX (supporting D3D12 and Vulkan). The Slang GFX backend is fully functional but considered experimental. To select the backend, the following build configurations are available:

• ReleaseD3D12 / DebugD3D12: Native D3D12 backend (recommended)
• ReleaseGFX-D3D12 / DebugGFX-D3D12: Slang GFX backend using D3D12 (experimental)
• ReleaseGFX-VK / DebugGFX-VK: Slang GFX backend using Vulkan (experimental)

Note: Some render passes (RTXGI, RTXDI, DLSS in particular) are not fully working with the new Slang GFX backend.

Falcor uses the Microsoft DirectX 12 Agility SDK to get access to the latest DirectX 12 features. Applications can enable the Agility SDK by putting FALCOR_EXPORT_D3D12_AGILITY_SDK in the main .cpp file. Mogwai, FalcorTest and RenderGraphEditor have the Agility SDK enabled by default.

To enable NVAPI support, head over to https://developer.nvidia.com/nvapi and download the latest version of NVAPI (this build is tested against version R470). Extract the content of the zip file into Source/Externals/.packman/ and rename R470-developer to nvapi.

Finally, set FALCOR_ENABLE_NVAPI to 1 in Source/Falcor/Core/FalcorConfig.h

To enable CUDA support, download CUDA 11.3.1. After running the installer, navigate to the CUDA installation (C:\Program Files\NVIDIA GPU Computing Tools\CUDA by default). Link or copy the v.11.3 folder into Source/Externals/.packman/cuda.

Finally, set FALCOR_ENABLE_CUDA to 1 in Source/Falcor/Core/FalcorConfig.h

To run the CudaInterop sample application located in Source/Samples/CudaInterop, you first have to add it to the solution (it's not added by default to avoid errors when opening the solution without CUDA installed).

To create a new CUDA enabled Falcor application, follow these steps:

1. Create a new CUDA Runtime project and add it to the Falcor solution.
2. In the Solution Explorer, right-click on References under the project and select Add Reference, then add Falcor.
3. Open the Property Manager and add the Falcor and FalcorCUDA property sheets to both Debug and Release. These are located in Source/Falcor.
4. Open the project's properties and go to CUDA/C++ and set CUDA Toolkit Custom Dir to $(SolutionDir)Source\Externals\.packman\cuda, then go to Linker -> System and change the SubSystem to Windows.

If you want to use Falcor's OptiX functionality (specifically the OptixDenoiser render pass) download the OptiX SDK (Falcor is currently tested against OptiX version 7.3) After running the installer, link or copy the OptiX SDK folder into Source\Externals\.packman\optix (i.e., file Source\Externals\.packman\optix\include\optix.h should exist).

Finally, set FALCOR_ENABLE_OPTIX to 1 in Source/Falcor/Core/FalcorConfig.h

Note: You also need CUDA installed to compile the OptixDenoiser render pass, see above for details.

Falcor ships with the following NVIDIA RTX SDKs:

• DLSS (https://github.com/NVIDIA/DLSS)
• RTXGI (https://github.com/NVIDIAGameWorks/RTXGI)
• RTXDI (https://github.com/NVIDIAGameWorks/RTXDI)
• NRD (https://github.com/NVIDIAGameWorks/RayTracingDenoiser)

Note that these SDKs are not under the same license as Falcor, see LICENSE.md for details.

FalcorConfig.h contains some flags which control Falcor's behavior.

• FALCOR_ENABLE_LOGGER - Enable/disable the logger. By default, it is set to 1.
• FALCOR_ENABLE_PROFILER - Enable/disable the internal CPU/GPU profiler. By default, it is set to 1.

• Falcor: Falcor's GitHub page.
• Documentation: Additional information and tutorials.
  • Getting Started
  • Render Graph Tutorials
• Rendering Resources A collection of scenes loadable in Falcor (pbrt-v4 format).
• ORCA: A collection of scenes and assets optimized for Falcor.
• Slang: Falcor's shading language and compiler.

If you use Falcor in a research project leading to a publication, please cite the project. The BibTex entry is

@Misc{Kallweit22,
   author =      {Simon Kallweit and Petrik Clarberg and Craig Kolb and Tom{'a}{\v s} Davidovi{\v c} and Kai-Hwa Yao and Theresa Foley and Yong He and Lifan Wu and Lucy Chen and Tomas Akenine-M{\"o}ller and Chris Wyman and Cyril Crassin and Nir Benty},
   title =       {The {Falcor} Rendering Framework},
   year =        {2022},
   month =       {3},
   url =         {https://github.com/NVIDIAGameWorks/Falcor},
   note =        {\url{https://github.com/NVIDIAGameWorks/Falcor}}
}