volpt

Volumetric path tracer written in C++.

WIP.

Features

• Unidirectional path tracing
• Next event estimation
• Homogeneous medium
• Heterogeneous medium
• Hero wavelength sampling for chromatic absorption/scattering coefficient
• Artist friendly parameter to control absorption/scattering coefficient
• Random walk subsurface scattering
• Load obj model

Requirements

• C++ (20>=)
• CMake (3.20>=)
• OpenMP
• spdlog
• Embree (>=3)
• OpenVDB

Build

|CMake option|Description| |:--|:--| |BUILD_TESTS|build tests|

git submodule update --init
mkdir build
cd build
cmake -DCMAKE_BUILD_TYPE=Release ..
make

Gallery

Misty cornell box

Subsurface scattering cornell box

Subsurface scattering bunny with glass surface

Smoke cornell box

Colored smoke

References

• Physically Based Rendering:From Theory To Implementation, Matt Pharr, Wenzel Jakob, and Greg Humphreys
• Wilkie, Alexander, et al. "Hero wavelength spectral sampling." Computer Graphics Forum. Vol. 33. No. 4. 2014.
• Novák, Jan, Andrew Selle, and Wojciech Jarosz. "Residual ratio tracking for estimating attenuation in participating media." ACM Trans. Graph. 33.6 (2014): 179-1.
• Chiang, Matt Jen-Yuan, Peter Kutz, and Brent Burley. "Practical and controllable subsurface scattering for production path tracing." ACM SIGGRAPH 2016 Talks (2016): 1-2.
• Fong, Julian, et al. "Production volume rendering: Siggraph 2017 course." ACM SIGGRAPH 2017 Courses. 2017. 1-79.
• Wrenninge, Magnus, Ryusuke Villemin, and Christophe Hery. Path traced subsurface scattering using anisotropic phase functions and non-exponential free flights. Tech. Rep. 17-07, Pixar. https://graphics. pixar. com/library/PathTracedSubsurface, 2017.
• Novák, Jan, et al. "Monte Carlo methods for volumetric light transport simulation." Computer Graphics Forum. Vol. 37. No. 2. 2018.
• Miller, Bailey, Iliyan Georgiev, and Wojciech Jarosz. "A null-scattering path integral formulation of light transport." ACM Transactions on Graphics (TOG) 38.4 (2019): 1-13.
• Georgiev, Iliyan, et al. "Integral formulations of volumetric transmittance." ACM Transactions on Graphics (TOG) 38.6 (2019): 1-17.