cgal/Polygon_mesh_processing/include/CGAL/Polygon_mesh_processing/curvature.h

476 lines
19 KiB
C++

// Copyright (c) 2021 GeometryFactory (France).
// All rights reserved.
//
// This file is part of CGAL (www.cgal.org).
//
// $URL$
// $Id$
// SPDX-License-Identifier: GPL-3.0-or-later OR LicenseRef-Commercial
//
//
// Author(s) : Andreas Fabri,
// Mael Rouxel-Labbé
#ifndef CGAL_PMP_CURVATURE_H
#define CGAL_PMP_CURVATURE_H
#include <CGAL/license/Polygon_mesh_processing/measure.h>
#include <CGAL/boost/graph/named_params_helper.h>
#include <CGAL/Named_function_parameters.h>
#include <CGAL/Polygon_mesh_processing/measure.h>
#include <CGAL/Weights/cotangent_weights.h>
#include <cmath>
#include <algorithm>
namespace CGAL {
namespace Polygon_mesh_processing {
/**
* \ingroup PMP_measure_grp
*
* computes the sum of the angles around a vertex.
*
* The angle sum is given in degrees.
*
* @tparam PolygonMesh a model of `FaceGraph`
* @tparam NamedParameters a sequence of \ref bgl_namedparameters "Named Parameters"
*
* @param v the vertex whose sum of angles is computed
* @param pmesh the polygon mesh to which `v` belongs
* @param np an optional sequence of \ref bgl_namedparameters "Named Parameters" among the ones listed below
*
* \cgalNamedParamsBegin
* \cgalParamNBegin{vertex_point_map}
* \cgalParamDescription{a property map associating points to the vertices of `pmesh`}
* \cgalParamType{a class model of `ReadablePropertyMap` with `boost::graph_traits<PolygonMesh>::%vertex_descriptor`
* as key type and `%Point_3` as value type}
* \cgalParamDefault{`boost::get(CGAL::vertex_point, pmesh)`}
* \cgalParamNEnd
*
* \cgalParamNBegin{geom_traits}
* \cgalParamDescription{an instance of a geometric traits class}
* \cgalParamType{The traits class must provide the nested functor `Compute_approximate_angle_3`,
* model of `Kernel::ComputeApproximateAngle_3`.}
* \cgalParamDefault{a \cgal kernel deduced from the point type, using `CGAL::Kernel_traits`}
* \cgalParamExtra{The geometric traits class must be compatible with the vertex point type.}
* \cgalParamNEnd
* \cgalNamedParamsEnd
*
* @return the sum of angles around `v`. The return type `FT` is a number type either deduced
* from the `geom_traits` \ref bgl_namedparameters "Named Parameters" if provided,
* or the geometric traits class deduced from the point property map of `pmesh`.
*
* \warning This function involves trigonometry.
*/
template<typename PolygonMesh,
typename CGAL_NP_TEMPLATE_PARAMETERS>
#ifdef DOXYGEN_RUNNING
FT
#else
typename GetGeomTraits<PolygonMesh, CGAL_NP_CLASS>::type::FT
#endif
angle_sum(typename boost::graph_traits<PolygonMesh>::vertex_descriptor v,
const PolygonMesh& pmesh,
const CGAL_NP_CLASS& np = parameters::default_values())
{
using parameters::choose_parameter;
using parameters::get_parameter;
using Geom_traits = typename GetGeomTraits<PolygonMesh, CGAL_NP_CLASS>::type;
using FT = typename Geom_traits::FT;
typename GetVertexPointMap<PolygonMesh, CGAL_NP_CLASS>::const_type
vpm = choose_parameter(get_parameter(np, internal_np::vertex_point),
get_const_property_map(CGAL::vertex_point, pmesh));
Geom_traits gt = choose_parameter<Geom_traits>(get_parameter(np, internal_np::geom_traits));
CGAL_precondition(is_valid_vertex_descriptor(v, pmesh));
typename Geom_traits::Compute_approximate_angle_3 approx_angle = gt.compute_approximate_angle_3_object();
FT angle_sum = 0;
for(auto h : halfedges_around_source(v, pmesh))
{
if(is_border(h, pmesh))
continue;
angle_sum += approx_angle(get(vpm, target(h, pmesh)),
get(vpm, source(h, pmesh)),
get(vpm, source(prev(h,pmesh), pmesh)));
}
return angle_sum;
}
// Discrete Gaussian Curvature
/**
* \ingroup PMP_measure_grp
*
* computes the discrete Gaussian curvature at a vertex.
*
* We refer to Meyer et al. \cgalCite{cgal:mdsb-ddgot-02} for the definition of <i>discrete Gaussian curvature</i>.
*
* @tparam TriangleMesh a model of `FaceGraph`
* @tparam NamedParameters a sequence of \ref bgl_namedparameters "Named Parameters"
*
* @param v the vertex whose discrete Gaussian curvature is being computed
* @param tmesh the triangle mesh to which `v` belongs
* @param np an optional sequence of \ref bgl_namedparameters "Named Parameters" among the ones listed below
*
* \cgalNamedParamsBegin
* \cgalParamNBegin{vertex_point_map}
* \cgalParamDescription{a property map associating points to the vertices of `tmesh`}
* \cgalParamType{a class model of `ReadablePropertyMap` with `boost::graph_traits<TriangleMesh>::%vertex_descriptor`
* as key type and `%Point_3` as value type}
* \cgalParamDefault{`boost::get(CGAL::vertex_point, tmesh)`}
* \cgalParamNEnd
*
* \cgalParamNBegin{geom_traits}
* \cgalParamDescription{an instance of a geometric traits class}
* \cgalParamType{The traits class must be a model of `Kernel`.}
* \cgalParamDefault{a \cgal kernel deduced from the point type, using `CGAL::Kernel_traits`}
* \cgalParamExtra{The geometric traits class must be compatible with the vertex point type.}
* \cgalParamNEnd
* \cgalNamedParamsEnd
*
* @return the discrete Gaussian curvature at `v`. The return type `FT` is a number type either deduced
* from the `geom_traits` \ref bgl_namedparameters "Named Parameters" if provided,
* or the geometric traits class deduced from the point property map of `tmesh`.
*
* \warning This function involves trigonometry.
* \warning The current formulation is not well defined for border vertices.
*
* \pre `tmesh` is a triangle mesh
*/
template <typename TriangleMesh,
typename CGAL_NP_TEMPLATE_PARAMETERS>
#ifdef DOXYGEN_RUNNING
FT
#else
typename GetGeomTraits<TriangleMesh, CGAL_NP_CLASS>::type::FT
#endif
discrete_Gaussian_curvature(typename boost::graph_traits<TriangleMesh>::vertex_descriptor v,
const TriangleMesh& tmesh,
const CGAL_NP_CLASS& np = parameters::default_values())
{
using parameters::choose_parameter;
using parameters::get_parameter;
using GeomTraits = typename GetGeomTraits<TriangleMesh, CGAL_NP_CLASS>::type;
using FT = typename GeomTraits::FT;
using Vector_3 = typename GeomTraits::Vector_3;
using VertexPointMap = typename GetVertexPointMap<TriangleMesh, CGAL_NP_CLASS>::const_type;
using halfedge_descriptor = typename boost::graph_traits<TriangleMesh>::halfedge_descriptor;
GeomTraits gt = choose_parameter<GeomTraits>(get_parameter(np, internal_np::geom_traits));
VertexPointMap vpm = choose_parameter(get_parameter(np, internal_np::vertex_point),
get_const_property_map(vertex_point, tmesh));
typename GeomTraits::Construct_vector_3 vector =
gt.construct_vector_3_object();
typename GeomTraits::Construct_cross_product_vector_3 cross_product =
gt.construct_cross_product_vector_3_object();
typename GeomTraits::Compute_scalar_product_3 scalar_product =
gt.compute_scalar_product_3_object();
typename GeomTraits::Compute_squared_length_3 squared_length =
gt.compute_squared_length_3_object();
FT angle_sum = 0;
for(halfedge_descriptor h : CGAL::halfedges_around_target(v, tmesh))
{
if(is_border(h, tmesh))
continue;
const Vector_3 v0 = vector(get(vpm, v), get(vpm, target(next(h, tmesh), tmesh))); // p1p2
const Vector_3 v1 = vector(get(vpm, v), get(vpm, source(h, tmesh))); // p1p0
const FT dot = scalar_product(v0, v1);
const Vector_3 cross = cross_product(v0, v1);
const FT sqcn = squared_length(cross);
if(is_zero(dot))
{
angle_sum += CGAL_PI/FT(2);
}
else
{
if(is_zero(sqcn)) // collinear
{
if(dot < 0)
angle_sum += CGAL_PI;
// else
// angle_sum += 0;
}
else
{
angle_sum += std::atan2(CGAL::approximate_sqrt(sqcn), dot);
}
}
}
Weights::Secure_cotangent_weight_with_voronoi_area<TriangleMesh, VertexPointMap, GeomTraits> wc(tmesh, vpm, gt);
const FT gaussian_curvature = (2 * CGAL_PI - angle_sum) / wc.voronoi(v);
return gaussian_curvature;
}
/**
* \ingroup PMP_measure_grp
*
* computes the discrete Gaussian curvatures at the vertices of a mesh.
*
* We refer to Meyer et al. \cgalCite{cgal:mdsb-ddgot-02} for the definition of <i>discrete Gaussian curvature</i>.
*
* @tparam TriangleMesh a model of `FaceGraph`
* @tparam VertexCurvatureMap must be a model of `WritablePropertyMap` with key type
* `boost::graph_traits<TriangleMesh>::%vertex_descriptor` and value type `FT`,
* which is either `geom_traits::FT` if this named parameter is provided,
* or `kernel::FT` with the kernel deduced from from the point property map of `tmesh`.
* @tparam NamedParameters a sequence of \ref bgl_namedparameters "Named Parameters"
*
* @param tmesh the triangle mesh to which `v` belongs
* @param vcm the property map that contains the computed discrete curvatures
* @param np an optional sequence of \ref bgl_namedparameters "Named Parameters" among the ones listed below
*
* \cgalNamedParamsBegin
* \cgalParamNBegin{vertex_point_map}
* \cgalParamDescription{a property map associating points to the vertices of `tmesh`}
* \cgalParamType{a class model of `ReadablePropertyMap` with `boost::graph_traits<TriangleMesh>::%vertex_descriptor`
* as key type and `%Point_3` as value type}
* \cgalParamDefault{`boost::get(CGAL::vertex_point, tmesh)`}
* \cgalParamNEnd
*
* \cgalParamNBegin{geom_traits}
* \cgalParamDescription{an instance of a geometric traits class}
* \cgalParamType{The traits class must be a model of `Kernel`.}
* \cgalParamDefault{a \cgal kernel deduced from the point type, using `CGAL::Kernel_traits`}
* \cgalParamExtra{The geometric traits class must be compatible with the vertex point type.}
* \cgalParamNEnd
* \cgalNamedParamsEnd
*
* \warning This function involves trigonometry.
* \warning The current formulation is not well defined for border vertices.
*
* \pre `tmesh` is a triangle mesh
*/
template <typename TriangleMesh,
typename VertexCurvatureMap,
typename CGAL_NP_TEMPLATE_PARAMETERS>
void discrete_Gaussian_curvatures(const TriangleMesh& tmesh,
VertexCurvatureMap vcm,
const CGAL_NP_CLASS& np = parameters::default_values())
{
using vertex_descriptor = typename boost::graph_traits<TriangleMesh>::vertex_descriptor;
for(vertex_descriptor v : vertices(tmesh))
{
put(vcm, v, discrete_Gaussian_curvature(v, tmesh, np));
// std::cout << "curvature: " << get(vcm, v) << std::endl;
}
}
// Discrete Mean Curvature
/**
* \ingroup PMP_measure_grp
*
* computes the discrete mean curvature at a vertex.
*
* We refer to Meyer et al. \cgalCite{cgal:mdsb-ddgot-02} for the definition of <i>discrete mean curvature</i>.
*
* @tparam TriangleMesh a model of `FaceGraph`
* @tparam NamedParameters a sequence of \ref bgl_namedparameters "Named Parameters"
*
* @param v the vertex whose discrete mean curvature is being computed
* @param tmesh the triangle mesh to which `v` belongs
* @param np an optional sequence of \ref bgl_namedparameters "Named Parameters" among the ones listed below
*
* \cgalNamedParamsBegin
* \cgalParamNBegin{vertex_point_map}
* \cgalParamDescription{a property map associating points to the vertices of `tmesh`}
* \cgalParamType{a class model of `ReadablePropertyMap` with `boost::graph_traits<TriangleMesh>::%vertex_descriptor`
* as key type and `%Point_3` as value type}
* \cgalParamDefault{`boost::get(CGAL::vertex_point, tmesh)`}
* \cgalParamNEnd
*
* \cgalParamNBegin{geom_traits}
* \cgalParamDescription{an instance of a geometric traits class}
* \cgalParamType{The traits class must be a model of `Kernel`.}
* \cgalParamDefault{a \cgal kernel deduced from the point type, using `CGAL::Kernel_traits`}
* \cgalParamExtra{The geometric traits class must be compatible with the vertex point type.}
* \cgalParamNEnd
* \cgalNamedParamsEnd
*
* @return the discrete mean curvature at `v`. The return type `FT` is a number type either deduced
* from the `geom_traits` \ref bgl_namedparameters "Named Parameters" if provided,
* or the geometric traits class deduced from the point property map of `tmesh`.
*
* \warning The current formulation is not well defined for border vertices.
*
* \pre `tmesh` is a triangle mesh
*/
template <typename TriangleMesh,
typename CGAL_NP_TEMPLATE_PARAMETERS>
#ifdef DOXYGEN_RUNNING
FT
#else
typename GetGeomTraits<TriangleMesh, CGAL_NP_CLASS>::type::FT
#endif
discrete_mean_curvature(typename boost::graph_traits<TriangleMesh>::vertex_descriptor v,
const TriangleMesh& tmesh,
const CGAL_NP_CLASS& np = parameters::default_values())
{
using parameters::choose_parameter;
using parameters::get_parameter;
using GeomTraits = typename GetGeomTraits<TriangleMesh, CGAL_NP_CLASS>::type;
using FT = typename GeomTraits::FT;
using Vector_3 = typename GeomTraits::Vector_3;
using VertexPointMap = typename GetVertexPointMap<TriangleMesh, CGAL_NP_CLASS>::const_type;
using Point_ref = typename boost::property_traits<VertexPointMap>::reference;
using vertex_descriptor = typename boost::graph_traits<TriangleMesh>::vertex_descriptor;
using halfedge_descriptor = typename boost::graph_traits<TriangleMesh>::halfedge_descriptor;
GeomTraits gt = choose_parameter<GeomTraits>(get_parameter(np, internal_np::geom_traits));
VertexPointMap vpm = choose_parameter(get_parameter(np, internal_np::vertex_point),
get_const_property_map(vertex_point, tmesh));
#if 0
typename GeomTraits::Compute_squared_distance_3 squared_distance =
gt.compute_squared_distance_3_object();
typename GeomTraits::Compute_approximate_dihedral_angle_3 dihedral_angle =
gt.compute_approximate_dihedral_angle_3_object();
const FT two_pi = 2 * CGAL_PI;
FT hi = 0;
for(halfedge_descriptor h : CGAL::halfedges_around_target(v, tmesh))
{
const Point_3& p = get(vpm, source(h, tmesh));
const Point_3& q = get(vpm, target(h, tmesh));
const Point_3& r = get(vpm, target(next(h, tmesh), tmesh));
const Point_3& s = get(vpm, target(next(opposite(h, tmesh), tmesh), tmesh));
const FT l = squared_distance(p,q);
FT phi = CGAL_PI * dihedral_angle(p, q, r, s) / FT(180);
if(phi < 0)
phi += two_pi;
if(phi > two_pi)
phi = two_pi;
hi += FT(0.5) * l * (CGAL_PI - phi);
}
return FT(0.5) * hi;
#else
typename GeomTraits::Construct_vector_3 vector =
gt.construct_vector_3_object();
typename GeomTraits::Construct_sum_of_vectors_3 vector_sum =
gt.construct_sum_of_vectors_3_object();
typename GeomTraits::Construct_scaled_vector_3 scaled_vector =
gt.construct_scaled_vector_3_object();
typename GeomTraits::Compute_squared_length_3 squared_length =
gt.compute_squared_length_3_object();
Weights::Secure_cotangent_weight_with_voronoi_area<TriangleMesh, VertexPointMap, GeomTraits> wc(tmesh, vpm, gt);
Vector_3 kh = vector(CGAL::NULL_VECTOR);
for(halfedge_descriptor h : CGAL::halfedges_around_target(v, tmesh))
{
const vertex_descriptor v1 = source(h, tmesh);
const Point_ref p0 = get(vpm, v);
const Point_ref p1 = get(vpm, v1);
FT local_c = 0;
if(!is_border(h, tmesh))
{
const vertex_descriptor v2 = target(next(h, tmesh), tmesh);
const Point_ref p2 = get(vpm, v2);
local_c += Weights::cotangent_3_clamped(p0, p2, p1, gt);
}
if(!is_border(opposite(h, tmesh), tmesh))
{
const vertex_descriptor v3 = target(next(opposite(h, tmesh), tmesh), tmesh);
const Point_ref p3 = get(vpm, v3);
local_c += Weights::cotangent_3_clamped(p1, p3, p0, gt);
}
kh = vector_sum(kh, scaled_vector(vector(p0, p1), local_c));
}
const FT khn = CGAL::approximate_sqrt(squared_length(kh));
const FT va = wc.voronoi(v);
CGAL_assertion(!is_zero(va));
const FT mean_curvature = khn / (FT(4) * va);
return mean_curvature;
#endif
}
/**
* \ingroup PMP_measure_grp
*
* computes the discrete mean curvatures at the vertices of a mesh.
*
* We refer to Meyer et al. \cgalCite{cgal:mdsb-ddgot-02} for the definition of <i>discrete mean curvature</i>.
*
* @tparam TriangleMesh a model of `FaceGraph`
* @tparam VertexCurvatureMap must be a model of `WritablePropertyMap` with key type
* `boost::graph_traits<TriangleMesh>::%vertex_descriptor` and value type `FT`,
* which is either `geom_traits::FT` if this named parameter is provided,
* or `kernel::FT` with the kernel deduced from from the point property map of `tmesh`.
* @tparam NamedParameters a sequence of \ref bgl_namedparameters "Named Parameters"
*
* @param tmesh the triangle mesh to which `v` belongs
* @param vcm the property map that contains the computed discrete curvatures
* @param np an optional sequence of \ref bgl_namedparameters "Named Parameters" among the ones listed below
*
* \cgalNamedParamsBegin
* \cgalParamNBegin{vertex_point_map}
* \cgalParamDescription{a property map associating points to the vertices of `tmesh`}
* \cgalParamType{a class model of `ReadablePropertyMap` with `boost::graph_traits<TriangleMesh>::%vertex_descriptor`
* as key type and `%Point_3` as value type}
* \cgalParamDefault{`boost::get(CGAL::vertex_point, tmesh)`}
* \cgalParamNEnd
*
* \cgalParamNBegin{geom_traits}
* \cgalParamDescription{an instance of a geometric traits class}
* \cgalParamType{The traits class must be a model of `Kernel`.}
* \cgalParamDefault{a \cgal kernel deduced from the point type, using `CGAL::Kernel_traits`}
* \cgalParamExtra{The geometric traits class must be compatible with the vertex point type.}
* \cgalParamNEnd
* \cgalNamedParamsEnd
*
* \warning The current formulation is not well defined for border vertices.
*
* \pre `tmesh` is a triangle mesh
*/
template <typename TriangleMesh,
typename VertexCurvatureMap,
typename CGAL_NP_TEMPLATE_PARAMETERS>
void discrete_mean_curvatures(const TriangleMesh& tmesh,
VertexCurvatureMap vcm,
const CGAL_NP_CLASS& np = parameters::default_values())
{
using vertex_descriptor = typename boost::graph_traits<TriangleMesh>::vertex_descriptor;
for(vertex_descriptor v : vertices(tmesh))
put(vcm, v, discrete_mean_curvature(v, tmesh, np));
}
} // namespace Polygon_mesh_processing
} // namespace CGAL
#endif //CGAL_PMP_CURVATURE_H