cgal/Surface_mesh_approximation/include/CGAL/vsa_mesh_approximation.h

162 lines
7.0 KiB
C++

#ifndef CGAL_SURFACE_MESH_APPROXIMATION_VSA_MESH_APPROXIMATION_H
#define CGAL_SURFACE_MESH_APPROXIMATION_VSA_MESH_APPROXIMATION_H
#include <CGAL/license/Surface_mesh_approximation.h>
#include <CGAL/vsa_metrics.h>
#include <CGAL/vsa_approximation.h>
#include <CGAL/internal/Surface_mesh_approximation/named_function_params.h>
#include <CGAL/internal/Surface_mesh_approximation/named_params_helper.h>
#include <CGAL/Polyhedron_3.h>
#include <CGAL/property_map.h>
#include <boost/graph/graph_traits.hpp>
#include <boost/optional.hpp>
namespace CGAL {
namespace VSA {
/*!
* \ingroup PkgTSMA
* @brief variational shape approximation of a triangle surface mesh.
* This function approximates the input mesh by fitting it with proxies.
*
* @tparam TriangleMesh model of `FaceGraph`.
* The descriptor types `boost::graph_traits<TriangleMesh>::%face_descriptor`
* and `boost::graph_traits<TriangleMesh>::%halfedge_descriptor` must be
* models of `Hashable`.
* If `TriangleMesh` has an internal property map for `CGAL::face_index_t`,
* and no `face_index_map` is given as a named parameter, then the internal one should be initialized.
* @tparam AnchorPointOutItr a class model of `OutputIterator` with `GeomTraits::Point_3` value type
* @tparam IndexedTrisOutItr a class model of `OutputIterator` with `std::vector<std::size_t>` value type
* @tparam NamedParameters a sequence of \ref namedparameters
*
* @param tm_in a triangle surface mesh to be approximated
* @param[out] apts_out_itr output iterator over anchor points
* @param[out] tris_out_itr output iterator over indexed triangles (triplets of integers referring to anchor points)
* @param np optional sequence of \ref namedparameters among the ones listed below
* @return true if the indexed triangles represent a valid 2-manifold, oriented surface mesh, and false otherwise.
*
* \cgalNamedParamsBegin
* \cgalParamBegin{geom_traits} a geometric traits class instance, model of `Kernel`.
* Exact constructions kernels are not supported by this function.
* \cgalParamEnd
* \cgalParamBegin{vertex_point_map} the property map with the points associated
* to the vertices of `tm_in`. Instance of a class model of `ReadWritePropertyMap`.
* \cgalParamEnd
* \cgalParamBegin{init_method} selection of initialization method.
* \cgalParamEnd
* \cgalParamBegin{max_nb_proxies} maximum number of proxies to approximate the geometry.
* \cgalParamEnd
* \cgalParamBegin{min_error_drop} minimum error drop of the approximation, expressed in ratio between two iterations of proxy addition.
* \cgalParamEnd
* \cgalParamBegin{iterations} number of relaxation iterations after seeding.
* \cgalParamEnd
* \cgalParamBegin{inner_iterations} number of relaxation iterations during seeding.
* \cgalParamEnd
* \cgalParamBegin{mesh_chord_error} maximum chord approximation error use for mesh construction.
* \cgalParamEnd
* \cgalParamBegin{face_proxy_map} property map containing the assigned proxy index of each face of input mesh `tm_in`.
* \cgalParamEnd
* \cgalParamBegin{proxies} output iterator over proxies.
* \cgalParamEnd
* \cgalParamBegin{anchor_vertices} output iterator over anchor vertices, defined on the input mesh `tm_in`.
* \cgalParamEnd
* \cgalParamBegin{output_mesh} polyhedral surface mesh derived from the indexed facet set. The polyhedron is not empty only
* when the indexed face set represents a 2-manifold, oriented surface triangle mesh.
* \cgalParamEnd
* \cgalNamedParamsEnd
*/
template <typename TriangleMesh,
typename AnchorPointOutItr,
typename IndexedTrisOutItr,
typename NamedParameters>
bool mesh_approximation(const TriangleMesh &tm_in,
AnchorPointOutItr apts_out_itr,
IndexedTrisOutItr tris_out_itr,
const NamedParameters &np)
{
using boost::get_param;
using boost::choose_param;
typedef typename GetGeomTraits<TriangleMesh, NamedParameters>::type Geom_traits;
typedef typename Geom_traits::FT FT;
typedef typename GetVertexPointMap<TriangleMesh, NamedParameters>::type Vertex_point_map;
Vertex_point_map point_pmap = choose_param(get_param(np, internal_np::vertex_point),
get_property_map(vertex_point, const_cast<TriangleMesh &>(tm_in)));
typedef CGAL::VSA::Mesh_approximation<TriangleMesh, Vertex_point_map> L21_approx;
typedef typename L21_approx::Error_metric L21_metric;
typedef typename L21_approx::Proxy_fitting L21_proxy_fitting;
L21_approx approx(tm_in, point_pmap);
L21_metric l21_metric(tm_in);
L21_proxy_fitting l21_fitting(tm_in);
approx.set_metric(l21_metric, l21_fitting);
// default hierarchical initialization
CGAL::VSA::Seeding method = choose_param(
get_param(np, internal_np::init_method), CGAL::VSA::Hierarchical);
boost::optional<std::size_t> max_nb_proxies = choose_param(
get_param(np, internal_np::max_nb_proxies), boost::optional<std::size_t>());
boost::optional<FT> min_error_drop = choose_param(
get_param(np, internal_np::min_error_drop), boost::optional<FT>());
std::size_t inner_iterations = choose_param(get_param(np, internal_np::inner_iterations), 5);
approx.init(method, max_nb_proxies, min_error_drop, inner_iterations);
const std::size_t iterations = choose_param(get_param(np, internal_np::iterations), 10);
approx.run(iterations);
#ifdef CGAL_SURFACE_MESH_APPROXIMATION_DEBUG
std::cout << "#px = " << approx.get_proxies_size()
<< ", #itr = " << iterations
<< ", #inner_itr = " << inner_iterations << std::endl;
#endif
typedef typename boost::lookup_named_param_def<
internal_np::facet_proxy_map_t,
NamedParameters,
internal_np::vsa_no_output_t>::type FPMap;
FPMap fproxymap = choose_param(
get_param(np, internal_np::facet_proxy_map), internal_np::vsa_no_output);
get_proxy_map(approx, fproxymap);
typedef CGAL::Polyhedron_3<Geom_traits> PolyhedronSurface;
PolyhedronSurface tmp_poly;
PolyhedronSurface * const tm_out = choose_param(get_param(np, internal_np::output_mesh), &tmp_poly);
const FT chord_error = choose_param(get_param(np, internal_np::mesh_chord_error), FT(1.0));
const bool is_manifold = approx.extract_mesh(*tm_out, chord_error);
typedef typename boost::lookup_named_param_def<
internal_np::anchor_vertices_t,
NamedParameters,
internal_np::vsa_no_output_t>::type AnchorVertexOutItr;
AnchorVertexOutItr avtx_out_itr = choose_param(
get_param(np, internal_np::anchor_vertices) , internal_np::vsa_no_output);
get_anchor_vertices(approx, avtx_out_itr);
// get anchor points
get_anchor_points(approx, apts_out_itr);
// get indexed triangles
get_indexed_triangles(approx, tris_out_itr);
typedef typename boost::lookup_named_param_def <
internal_np::proxies_t,
NamedParameters,
internal_np::vsa_no_output_t>::type ProxiesOutItr;
ProxiesOutItr pxies_out_itr = choose_param(
get_param(np, internal_np::proxies), internal_np::vsa_no_output);
get_proxies(approx, pxies_out_itr);
return is_manifold;
}
} // end namespace VSA
} // end namespace CGAL
#endif // CGAL_SURFACE_MESH_APPROXIMATION_VSA_MESH_APPROXIMATION_H