libigl/docs/index.md

libigl - A simple C++ geometry processing library

This detailed documentation browser is automatically generated from the comments in libigl header (.h) files.

In general, each libigl function (e.g., igl::func) will be defined in a correspondingly named header file (e.g., #include <igl/func.h>).

The core library only depends on the standard template library (std::) and Eigen. These functions reside directly the igl:: namespace

Functions with further dependencies reside in a corresonding sub-namespace. For example, the function igl::spectra::lscm depends on the Spectra library so it resides in the igl::spectra:: namespace.

Functions which depend on external code under a copyleft license reside in the igl::copyleft:: namepsace.

Most libigl functions are templated over the Eigen matrix inputs and outputs. Callers can choose their own scalar types (e.g., double/float) and storage orders (Eigen::ColMajor/Eigen::RowMajor). Libigl can be used as a:

• header only library (via CMake, make sure LIBIGL_USE_STATIC_LIBRARY=OFF) and insure that IGL_STATIC_LIBRARY is not defined_ when compiling --- easiest if you're new to libigl, or
• static library (LIBIGL_USE_STATIC_LIBRARY=ON → IGL_STATIC_LIBRARY is defined) --- speeds up repeated compilation.

The libigl static library is filled with explicit template instantiations for common Eigen inputs and outputs. If the library doesn't contain your types, you may get some form of linker error (e.g., Undefined symbols for architecture, undefined reference to or unresolved external symbol).

You can fix this by:

1. Switching to header only mode for your project,

2. Making a file in your project to compile the missing templates. E.g., my_templates.cpp

   #ifdef IGL_STATIC_LIBRARY
   #undef IGL_STATIC_LIBRARY
   #endif
   #include <igl/per_vertex_normals.h>
   template void igl::per_vertex_normals<Eigen::Matrix<float, -1, -1, 0, -1, -1>, Eigen::Matrix<int, -1, -1, 0, -1, -1>, Eigen::Matrix<float, -1, -1, 0, -1, -1> >(Eigen::MatrixBase<Eigen::Matrix<float, -1, -1, 0, -1, -1> > const&, Eigen::MatrixBase<Eigen::Matrix<int, -1, -1, 0, -1, -1> > const&, Eigen::PlainObjectBase<Eigen::Matrix<float, -1, -1, 0, -1, -1> >&); 
   

3. Submit a PR containing your missing template to the development branch of libigl

4. Change your input/output types to match existing templates (e.g., Eigen::MatrixXd).

https://libigl.github.io/

https://github.com/libigl/libigl/