https://github.com/libigl/libigl/
Get started with:
git clone --recursive https://github.com/libigl/libigl.git
libigl is a simple C++ geometry processing library. We have a wide functionality including construction of sparse discrete differential geometry operators and finite-elements matrices such as the cotangent Laplacian and diagonalized mass matrix, simple facet and edge-based topology data structures, mesh-viewing utilities for OpenGL and GLSL, and many core functions for matrix manipulation which make Eigen feel a lot more like MATLAB.
It is a header-only library. You do not need to compile anything to use,
just include igl headers (e.g. #include <igl/cotmatrix.h>
) and run. Each
header file contains a single function (e.g. igl/cotmatrix.h
contains
igl::cotmatrix()
). Most are tailored to operate on a generic triangle mesh
stored in an n-by-3 matrix of vertex positions V and an m-by-3 matrix of
triangle indices F.
Optionally the library may also be pre-compiled into a statically linked library, for faster compile times with your projects. This only effects compile time (run-time performance and behavior is identical). If in doubt, use the header-only default mode: (i.e. just include the headers you want to use).
We use the Eigen library heavily in our code. Our group prototypes a lot in MATLAB, and we have a useful MATLAB to libigl+Eigen conversion table.
We regularly test compiling our library on Mac OS X with clang, Linux with gcc and Windows with Visual Studio 2015 Community Edition.
As of version 1.0, libigl includes an introductory tutorial that covers many functionalities.
Libigl is a header-only library. You do not need to build anything to
install. Simply add libigl/include
to your include path and include relevant
headers. Here is a small "Hello, World" program:
#include <igl/cotmatrix.h>
#include <Eigen/Dense>
#include <Eigen/Sparse>
#include <iostream>
int main()
{
Eigen::MatrixXd V(4,2);
V<<0,0,
1,0,
1,1,
0,1;
Eigen::MatrixXi F(2,3);
F<<0,1,2,
0,2,3;
Eigen::SparseMatrix<double> L;
igl::cotmatrix(V,F,L);
std::cout<<"Hello, mesh: "<<std::endl<<L*V<<std::endl;
return 0;
}
If you save this in hello.cpp
, then you could compile this with (assuming
Eigen is installed in /usr/local/include/eigen3
):
g++ -std=c++11 -I/usr/local/include/eigen3 -I./libigl/include/ hello.cpp -o hello
Running ./hello
would then produce
Hello, mesh:
0.5 0.5
-0.5 0.5
-0.5 -0.5
0.5 -0.5
Dependencies are on a per-include basis and the majority of the functions in libigl depends only on the Eigen library.
For more information see our tutorial.
Libigl compartmentalizes its optional dependences via its directory
organization in the include/
folder. All header files located directly in
the include/igl/
folder have only stl and Eigen as dependencies. For example,
all of the headers that depend on CGAL are located in include/igl/cgal
. For a
full list of optional dependencies check optional/CMakeLists.txt
.
The include/igl/cgal/*.h
headers depend on CGAL. It has come to our attention
that CGAL does not work properly with GCC 4.8. To the best of our knowledge,
GCC 4.7 and clang will work correctly.
Some of our functions will take advantage of OpenMP if available. However, it has come to our attention that Visual Studio + Eigen + OpenMP does not work properly. Since we use OpenMP only to improve performance, we recommend avoiding OpenMP on Windows or proceeding with caution.
You can keep up to date by cloning a read-only copy of our GitHub repository.
We rely heavily on Eigen. Nearly all inputs and outputs are Eigen matrices of
some kind. However, we currently only officially support Eigen's default
column-major ordering. That means, we do not expect our code to work for
matrices using the Eigen::RowMajor
flag. If you can, change definitions like:
Eigen::Matrix<double, Eigen::Dynamic, 3, Eigen::RowMajor> A;
to
Eigen::Matrix<double, Eigen::Dynamic, 3, Eigen::ColMajor> A;
// or simply
Eigen::Matrix<double, Eigen::Dynamic, 3> A;
We hope to fix this, or at least identify which functions are safe (many of them probably work just fine). This requires setting up unit testing, which is a major todo for our development.
Libigl uses git submodules for its optional dependencies, in particular, those needed by the OpenGL viewer to run the examples in the tutorial. Git submodules allow use to treat clones of other libraries as sub-directories within ours while separating our commits. Read the documentation for a detailed explanation, but essentially our libigl repo stores a hash for each of its subrepos containing which version to update to. When a change is introduced in a dependencies repo we can incorporate that change by pulling in our sub-repo and updating (i.e. committing) that change to the hash.
When pulling new changes to libigl it's also a good idea to update changes to subrepos:
git pull
git submodule update --recursive
Libigl maintains separate repository for unit testing.
If you are interested in joining development, please fork the repository and submit a pull request with your changes.
libigl is primarily MPL2 licensed (FAQ). Some files contain third-party code under other licenses. We're currently in the processes of identifying these and marking appropriately.
If you use libigl in your academic projects, please cite the papers we implement as appropriate. To cite the library in general, you could use this BibTeX entry:
@misc{libigl,
title = {{libigl}: A simple {C++} geometry processing library},
author = {Alec Jacobson and Daniele Panozzo and others},
note = {http://libigl.github.io/libigl/},
year = {2016},
}
Libigl is used by many research groups around the world. In 2015, it won the Eurographics/ACM Symposium on Geometry Processing software award. Here are a few labs/companies/institutions using libigl:
- Adobe Research
- Mesh, consultants, Canada
- Pixar Research
- Spine by Esoteric Software is an animation tool dedicated to 2D characters.
- Columbia University, Columbia Computer Graphics Group, USA
- Cornell University, USA
- Czech Technical University in Prague, Czech
- EPF Lausanne, Computer Graphics and Geometry Laboratory, Switzerland
- ETH Zurich, Interactive Geometry Lab and Advanced Technologies Lab, Swizterland
- George Mason University, CraGL, USA
- Hong Kong University of Science and Technology, Hong Kong
- National Institute of Informatics, Japan
- New York University, Media Research Lab, USA
- NYUPoly, Game Innovation Lab, USA
- TU Berlin, Germany
- TU Delft, Netherlands
- TU Wien, Austria
- Telecom ParisTech, Paris, France
- Universidade Federal de Santa Catarina, Brazil
- University College London, England
- University of California Berkeley, USA
- University of Cambridge, England
- University of Pennsylvania, USA
- University of Texas at Austin, USA
- University of Victoria, Canada
- Università della Svizzera Italiana, Switzerland
- Université Toulouse III Paul Sabatier, France
- Zhejiang University, China
Libigl is a group endeavor led by Alec Jacobson and Daniele Panozzo. Please contact us if you have questions or comments. For troubleshooting, please post an issue on github.
If you're using libigl in your projects, quickly drop us a note. Tell us who you are and what you're using it for. This helps us apply for funding and justify spending time maintaining this.
If you find bugs or have problems please use our github issue tracking page.
2016 Alec Jacobson, Daniele Panozzo, Christian Schüller, Olga Diamanti, Qingnan Zhou, Nico Pietroni, Stefan Brugger, Kenshi Takayama, Wenzel Jakob, Nikolas De Giorgis, Luigi Rocca, Leonardo Sacht, Kevin Walliman, Olga Sorkine-Hornung, and others.
Please see individual files for appropriate copyright notices.