Real-Time Rendering of Indirectly Visible Caustics

This repository contains the source code for the paper Real-Time Rendering of Indirectly Visible Caustics to be published at GRAPP 2022.

The code is based on Falcor 4.3, and adds a few bug fixes and utilities as well as a new render pass called ScreenSpaceCaustics which implements both Caustics Using Screen-Space Photon Mapping, H. Kim (2019) as well as our approach described in the previously-mentioned paper. The script Source/Mogwai/Data/ScreenSpaceCausticRenderer.py will set up an appropiate render graph using our technique.

The pre-requisites and installation instructions listed below are applicable to this project. Note that NVAPI, CUDA, and OptiX are all used and enabled by the project.

Falcor 4.3

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 2004 (May 2020 Update) 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 (make sure you have the latest driver)

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)

NVAPI installation

After cloning the repository, head over to https://developer.nvidia.com/nvapi and download the latest version of NVAPI (this build is tested against version R440). Extract the content of the zip file into Source/Externals/.packman/ and rename R440-developer to nvapi.

Finally, set _ENABLE_NVAPI to true in Source/Falcor/Core/FalcorConfig.h

CUDA Support

If you want to use CUDA C/C++ code as part of a Falcor project, then refer to the README located in the Source/Samples/CudaInterop/ for instructions on how to set up your environment to use CUDA with Falcor.

If you want to execute Slang-based shader code through CUDA using CUDAProgram, then you will need to copy or link the root directory of the CUDA SDK under Source/Externals/.packman/, as a directory named CUDA. Then, set _ENABLE_CUDA to true in Source/Falcor/Core/FalcorConfig.h

OptiX Support

If you want to use Falcor's OptiX functionality (specifically the OptiXDenoiser render pass), then refer to the README location in Source/Samples/OptixDenoiser for instructions on setting up your environment to use OptiX with Falcor.

In particular, you will need to copy or link the root directory of the OptiX SDK under Source/Externals/, as a directory named optix (i.e., Source/Externals/optix/include/optix.h should exist). Then, set _ENABLE_OPTIX to 1 in Source/Falcor/Core/FalcorConfig.h

Falcor Configuration

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

• _LOG_ENABLED - Enable/disable log messages. By default, it is set to true.
• _PROFILING_ENABLED - Enable/Disable the internal CPU/GPU profiler. By default, it is set to true.

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{Benty20,
   author =      {Nir Benty and Kai-Hwa Yao and Petrik Clarberg and Lucy Chen and Simon Kallweit and Tim Foley and Matthew Oakes and Conor Lavelle and Chris Wyman},
   title =       {The {Falcor} Rendering Framework},
   year =        {2020},
   month =       {08},
   url =         {https://github.com/NVIDIAGameWorks/Falcor},
   note=         {\url{https://github.com/NVIDIAGameWorks/Falcor}}
}