This is the code release attached to the paper Transfer Matrix Based Layered Materials Rendering presented at SIGGRAPH 2021.

This repository provides three BSDF plugins for the Mitsuba 0.6 renderer (https://github.com/mitsuba-renderer/mitsuba):

• tm2: Implements the 2-flux transfer model for opaque materials
• tm2_dielectric: Implements the 2-flux transfer model for transmissive materials
• tm6: Implements the 6-flux transfer model for opaque materials

Notes: Supplied code and data have been tested and validated on Windows 10 MSVC 2017 64-bits.

• Visual Studio Community 2017 with "C++ Desktop Development" tools: https://docs.microsoft.com/en-us/cpp/build/vscpp-step-0-installation?view=msvc-150

• Python 2.7.18: https://www.python.org/downloads/. Please make sure to enable the "Add python.exe to Path" option during the installation process.

• Git command line client: https://git-scm.com/

For the sake of simplicity, we assume C:/mitsuba/ as install directory, but the process remains valid for any other target location.

In a Git Bash prompt:

• $ cd /c/
• $ git clone https://github.com/mitsuba-renderer/mitsuba
• $ cd mitsuba
• $ git clone https://github.com/mitsuba-renderer/dependencies_win64 dependencies
• $ cp /c/mitsuba/dependencies/lib/*.dll /c/mitsuba/dependencies/bin/

Mitsuba uses SCons (https://www.scons.org/) as its internal build system.

To install SCons, uncompress the archive C:/mitsuba/dependencies/scons-2.5.1.zip and type the following commands in a VS2017 command prompt:

• $ cd "C:\mitsuba\dependencies\scons-2.5.1"
• $ python setup.py install

In a Git Bash prompt:

• $ cd /c/
• $ git clone https://github.com/laurent-lu/TMbLM-Rendering.git

• Copy all the files from C:/TMbLM-Rendering/plugins/ to C:/mitsuba/src/bsdfs/

• Add the following lines to C:/mitsuba/src/bsdfs/SConscript just before the Export('plugins') directive in order to include the plugins files in the Mitsuba build:

plugins += env.SharedLibrary('tm2', ['tm2.cpp'])
plugins += env.SharedLibrary('tm2_dielectric', ['tm2_dielectric.cpp'])
plugins += env.SharedLibrary('tm6', ['tm6.cpp'])

• Open C:/mitsuba/build/mitsuba-msvc2017.sln with Visual Studio 2017
• Select Release as build configuration
• Build the solution (Menu Build/Build solution)
• Copy all the files from C:/TMbLM-Rendering/data/ to C:/mitsuba/dist/data/

• Uncompress a scene .zip file from C:/TMbLM-Rendering/scenes/
• Drag and drop the XML scene file to C:/mitsuba/dist/mitsuba.exe to start the rendering. The corresponding output PNG image is saved in the scene folder at the end of the process.

Notes: Running C:/mitsuba/dist/mtsgui.exe results in a crash due to missing platform-specific Qt DLLs. Please see mitsuba-renderer/mitsuba#52 where this issue is discussed and a workaround is proposed if Mitsuba's GUI is wanted.

If you use this code, please consider citing our work accordingly:

@inproceedings{randrianandrasana:2021:tmblmr,
 author = {Randrianandrasana, Joël and Callet, Patrick and Lucas, Laurent},
 title = {{Transfer Matrix Based Layered Materials Rendering}},
 journal = {ACM Transactions on Graphics (Proceedings SIGGRAPH)},
 volume = {40},
 number = {4},
 month = {August},
 year = {2021},
 doi = {10.1145/3450626.3459859}
}

Feel free to send an e-mail to j.randrianandrasana[at]gmail.com or laurent.lucas[at]univ-reims.fr if you have any question.