compas_libigl

Opinionated COMPAS-compatible bindings for top-level algorithms of libigl.

Requirements

Anaconda(3)
COMPAS
CMake
Boost

Anaconda 3 can be obtained from the official website. With conda installing COMPAS is as simple as $ conda install COMPAS. Make sure you have the latest version of COMPAS. You can check the version by typing python -c “import compas; print(compas.__version__) in terminal.

Git Submodules

libigl
PyBind11
Eigen

These are configured in the .gitmodules file and will be cloned into the ext folder.

https://git-scm.com/book/en/v2/Git-Tools-Submodules https://git-scm.com/docs/git-submodule https://git-scm.com/docs/gitmodules

Make sure to clone the submodules together with the main repo.

git clone --recursive https://github.com/BlockResearchGroup/compas_libigl.git

Modules

The folder modules contains the wrapper code per module that should be added to compas_libigl. Each module is in a separate folder with its own CMakeLists.txt and a .cpp file with the wrapper code.

Environment

As with all things COMPAS, it is recommended to make a separate environment for experimenting with this package.

conda create -n igl python=3.7 COMPAS --yes
conda activate igl

On Mac, don't forget to add python.app

To make sure that you can build the modules that require CGAL, you should also install Boost into this environment.

conda install boost

Note that a conda install of Boost into an environment with Python 3.x will install Boost 1.70 and this is only supported since CMake 3.14.

To use the viewers, install compas_viewers and its dependencies.

conda install PySide2 PyOpenGL
pip install git+https://github.com/compas-dev/compas_viewers.git#egg=compas_viewers

Cmake

The project has three levels of CMakeLists.txt files.

/CMakeLists.txt

The top level file is located at the root of the project.

/modules/CMakeLists.txt

The second level file is in the modules folder. If you add a new wrapper module, make sure to register it in this file as well.

add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/xxx)

/modules/xxx/CMakeLists.txt

Finally there is a CMakeLists file per wrapper module. There the most relevant part is to link the correct libraries. For example, the module that wraps libigl's boolean operations requires CGAL and this should thus be reflected in the file.

target_link_libraries(booleans PRIVATE igl::cgal)

Compile & Install

On Mac

rm -rf build
pip install -e .

On Windows

rmdir build /s
pip install -e .

check Installation

To verify, start an interactive python session and import the package. This should not throw any errors.

>>> import compas
>>> import compas_libigl

Usage

The compiled libraries are added directly into the compas_libigl package. If you add a new wrapper, make sure to add a corresponding entry in the __init__.py file of the package.

Example scripts for simple use cases are located in the scripts folder.

If you make changes to the C++ part of compas_libigl you have to rebuild the package before these changes have an effect.

Known Issues

Boolean operations and their CSGtree variations depend on CGAL. On Windows, the installation of CGAL is problematic. Therefore, support for blooean operations is not enabled by default. To build compas_libigl with support for boolean operations, modify the following files:

modules/CMakeLists.txt:
- uncomment line 6 (# add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/csgtree))
- uncomment line 7 (# add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/booleans))
src/compas_libigl/__init__.py:
- uncomment line 5 (# from .booleans import *)
- uncomment line 6 (# from .csgtree import *)

jf---/compas_libigl