skeleton

Roberto Toro, May 2017.

Computes the mean curvature flow skeleton of a mesh. The command takes 3 arguments:

• argv[1]: Input mesh in .off format (by default, it will read data/elephant.off)
• argv[2]: Output skeleton in .cgal format (by default, it will write to skel.cgal)
• argv[3]: Output point correspondances in .cgal format (by default, it will write to correspondance.cgal)

There are additionally two python scripts, cgal2curves.py and cgal2graph.py, which take a skeleton in .cgal format and output either the curves converted into EditMesh's .txt format, or just a graph.

Compilation instructions

The code comes from the Skeleton example in CGAL, simple_mcfskel_example.cpp.

You need to install cgal.
Then add cgal to your path code ~/.bash_profile
# For creating cmake files with cgal export PATH="/Users/katja/code/cgal-releases-CGAL-4.13.1/Scripts/scripts/":${PATH}

Open a new terminal.
cd foldgraph/bin/skeleton/skeleton
ls should show skeleton.cpp and a data directory. (Remove everything else)

I originally used the script cgal_create_cmake_script to create a CMakeLists.txt file, and then modified it to include Eigen, and build a Release version. The CMakeLists.txt file should be like this:

# Created by the script cgal_create_cmake_script
# This is the CMake script for compiling a CGAL application.

# Use a line like this if your CGAL sits in an unusual location
# (no need for it if CGAL was installed using brew, for example)
set(CMAKE_PREFIX_PATH /Applications/_Sci/cgal-github/Installation/lib/cmake/CGAL)

set(CMAKE_BUILD_TYPE Release)

cmake_minimum_required(VERSION 3.1...3.14)
project( skeleton )

find_package(CGAL REQUIRED QUIET OPTIONAL_COMPONENTS Core )
include( ${CGAL_USE_FILE} )

find_package(Eigen3 3.0.91) 
include( ${EIGEN3_USE_FILE} )

create_single_source_cgal_program( "skeleton.cpp" )

Finally, run cmake . , then make, and the code is compiled.