Falcor 5.0-preview

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

The included path tracer requires NVAPI. Please make sure you have it set up properly, otherwise the path tracer won't work. You can find the instructions below.

Prerequisites

• 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 (see below)
• RTXDI (see below)

Microsoft DirectX 12 Agility SDK

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.

NVAPI

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

CUDA

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.

OptiX

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.

NRD

If you want to use Falcor's NRD (NVidia Real-Time Denoiser) based denoiser (specifically the NRDPass render pass) register to access the NRD SDK. Next, clone the GitHub repository from https://github.com/NVIDIAGameWorks/RayTracingDenoiser (Falcor is currently tested against NRD version 2.10) and execute the following steps:

• Switch to the NRD SDK directory.
• Run 1-Deploy.bat.
• Run 2-Build.bat and make sure to build both the Release and Debug builds.
• Run 3-Prepare NRD SDK.bat and make sure to copy the shader source code.
• Copy/move the content in the resulting _NRD_SDK folder over to Source/Externals/.packman/nrd.

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

DLSS

If you want to use Falcor's DLSS integration (specifically the DLSSPass render pass) download the DLSS SDK (Falcor is currently tested against DLSS SDK version 2.3.1). Unpack the SDK and copy/move the content in the nvngx_dlss_sdk folder over to Source/Externals/.packman/ngx.

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

RTXDI (RTX Direct Illumination)

Falcor has an (optional) RTXDI integration that your applications and render passes can use to efficiently sample from thousands or millions of lights.

Falcor does not come with RTXDI by default, as the SDK is distributed under a different license. Please visit the RTXDI developer page to register for access to the RTXDI source code, which you can access on Github after your access is approved. Falcor is currently tested against RTXDI version 1.2.1.

After downloading RTXDI, place the code in Source/Externals/.packman/rtxdi/ such that RTXDI repository maintains its relative file structure and the file Source/Externals/.packman/rtxdi/rtxdi-sdk/src/RTXDI.cpp exists. Also, set FALCOR_ENABLE_RTXDI to 1 in Source/Falcor/Core/FalcorConfig.h.

A simple sample render pass that uses RTXDI to render direct lighting is provided in Source/RenderPasses/RTXDIPass.

Falcor Configuration

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.

Resources

• Falcor: Falcor's GitHub page.
• Documentation: Additional information and tutorials.
  • Getting Started
  • Render Graph Tutorials
• ORCA: A collection of high quality scenes and assets optimized for Falcor.
• Slang: Falcor's shading language and compiler.

Citation

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

@Misc{Kallweit21,
   author =      {Simon Kallweit and Petrik Clarberg and Craig Kolb 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 =       {1},
   url =         {https://github.com/NVIDIAGameWorks/Falcor},
   note =        {\url{https://github.com/NVIDIAGameWorks/Falcor}}
}