Triangulated Surface Mesh Skeletonization Reference

Xiang Gao, Sébastien Loriot, and Andrea Tagliasacchi

This package provides a (1D) curve skeleton extraction algorithm for a triangulated polygonal mesh without borders based on the mean curvature flow. The particularity of this skeleton is that it captures the topology of the input. For each skeleton vertex one can obtain its location and its corresponding vertices from the input mesh. The code is generic and works with any model of the FaceListGraph concept.

Introduced in: CGAL 4.7
Depends on: CGAL and Solvers
BibTeX: cgal:glt-tsms-24b
License: GPL
Windows Demo: CGAL Lab

Classified Reference Pages

Concepts

• MeanCurvatureSkeletonizationTraits
• NormalEquationSparseLinearAlgebraTraits_d

Classes

• CGAL::Mean_curvature_flow_skeletonization

Todo:

doc+code: mention that to get a better skeleton that is closer to the medial axis, the surface must be sufficiently well sampled so that the Voronoi poles lie on the media axis (see Amenta's paper). Propose the usage of the isotropic remeshing and see if we add a boolean to do it automatically in the api (correspondence would be broken)

code: implement the random sampling of surface using the work started by Alexandru during its gsoc to get a better approximation of poles

code: expose in polygon mesh processing the function to compute the voronoi pole of a close triangle mesh

code: expose in polygon mesh processing the function to remesh locally a triangle mesh with the angle and edge length parameters

code: avoid using EPEC for the triangulation

Modules
	Concepts

Classes
class	CGAL::Mean_curvature_flow_skeletonization< TriangleMesh, Traits_, VertexPointMap_, SolverTraits_ >
	Function object that enables to extract the mean curvature flow skeleton of a triangulated surface mesh. More...

Functions
template<class TriangleMesh >
void	CGAL::extract_mean_curvature_flow_skeleton (const TriangleMesh &tmesh, typename Mean_curvature_flow_skeletonization< TriangleMesh >::Skeleton &skeleton)
	extracts a medially centered curve skeleton for the triangle mesh tmesh. This function uses the class CGAL::Mean_curvature_flow_skeletonization with the default parameters. This function is provided only if Eigen 3.2 (or greater) is available and CGAL_EIGEN3_ENABLED is defined.

Function Documentation

extract_mean_curvature_flow_skeleton()

template<class TriangleMesh >

void CGAL::extract_mean_curvature_flow_skeleton	(	const TriangleMesh &	tmesh,
		typename Mean_curvature_flow_skeletonization< TriangleMesh >::Skeleton &	skeleton
	)

#include <CGAL/extract_mean_curvature_flow_skeleton.h>

extracts a medially centered curve skeleton for the triangle mesh tmesh. This function uses the class CGAL::Mean_curvature_flow_skeletonization with the default parameters. This function is provided only if Eigen 3.2 (or greater) is available and CGAL_EIGEN3_ENABLED is defined.

Precondition

tmesh is a triangle mesh without borders and having exactly one connected component.

The specialization boost::property_map<TriangleMesh, CGAL::vertex_point_t>::type and get(vertex_point, tmesh) are defined.

The value type of boost::property_map<TriangleMesh, CGAL::vertex_point_t>::type is a point type from a CGAL Kernel.

Template Parameters

TriangleMesh

a model of FaceListGraph

Parameters

tmesh	input mesh
skeleton	graph that will contain the skeleton of tmesh. For each vertex descriptor vd of skeleton, the corresponding point and the set of input vertices that contracted to vd can be retrieved using skeleton[vd].point and skeleton[vd].vertices respectively.

Examples

Surface_mesh_skeletonization/segmentation_example.cpp, Surface_mesh_skeletonization/simple_mcfskel_example.cpp, and Surface_mesh_skeletonization/simple_mcfskel_sm_example.cpp.