Tet remeshing - add sizing field

Installation/CHANGES.md

@@ -89,6 +89,8 @@ Release date: June 2024
 - Introduced a new interactive program that demonstrates 2D arrangements embedded on the sphere called `earth`. The program (i) reads a database of all administrative boundaries of the countries in the world, (ii) displays the globe with all countries and land covered by water (which is land not covered by countries) on a window, and (ii) enables interaction with the user.
 
 ### [Tetrahedral Remeshing](https://doc.cgal.org/6.0/Manual/packages.html#PkgTetrahedralRemeshing)
+-   Added a sizing field as new parameter of `CGAL::tetrahedral_isotropic_remeshing()`, for non-uniform
+    and adaptive remeshing.
 -   **Breaking change**: The template parameters of
     `CGAL::Tetrahedral_remeshing::Remeshing_cell_base_3`
     have been modified, reverting changes introduced in CGAL 5.6.

Lab/demo/Lab/Plugins/Tetrahedral_remeshing/CMakeLists.txt

@@ -13,3 +13,9 @@ cgal_lab_plugin(
   ${tetRemeshingUI_FILES} KEYWORDS Tetrahedral_remeshing)
 target_link_libraries(tetrahedral_remeshing_plugin PUBLIC scene_c3t3_item
                                                           ${OPENGL_gl_LIBRARY})
+
+find_package(Eigen3 3.1.0 REQUIRED) #(3.1.0 or greater)
+include(CGAL_Eigen3_support)
+if(TARGET CGAL::Eigen3_support)
+  target_link_libraries(tetrahedral_remeshing_plugin PUBLIC CGAL::Eigen3_support)
+endif()

Lab/demo/Lab/Plugins/Tetrahedral_remeshing/Tetrahedral_remeshing_dialog.ui

@@ -9,8 +9,8 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>376</width>
-    <height>259</height>
+    <width>389</width>
+    <height>287</height>
    </rect>
   </property>
   <property name="windowTitle">
@@ -43,8 +43,28 @@
      <property name="title">
       <string>Tetrahedral remeshing</string>
      </property>
-     <layout class="QGridLayout" name="gridLayout_2" rowstretch="0,0,0,0,0" columnstretch="0,0">
-      <item row="1" column="1">
+     <layout class="QGridLayout" name="gridLayout_2" rowstretch="0,0,0,0,0,0" columnstretch="0,0,0">
+      <item row="4" column="0">
+       <widget class="QLabel" name="options_label">
+        <property name="text">
+         <string>Options :</string>
+        </property>
+        <property name="alignment">
+         <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
+        </property>
+       </widget>
+      </item>
+      <item row="5" column="1">
+       <widget class="QCheckBox" name="smoothEdges_checkBox">
+        <property name="toolTip">
+         <string extracomment="Smoothing of constrained polylines.\nWarning : this may reduce quality of dihedral angles."/>
+        </property>
+        <property name="text">
+         <string>Smooth constrained edges</string>
+        </property>
+       </widget>
+      </item>
+      <item row="2" column="1">
        <widget class="QSpinBox" name="nbIterations_spinbox">
         <property name="minimumSize">
          <size>
@@ -57,17 +77,23 @@
         </property>
        </widget>
       </item>
-      <item row="3" column="1">
-       <widget class="QCheckBox" name="protect_checkbox">
-        <property name="text">
-         <string>Protect boundaries</string>
+      <item row="0" column="1">
+       <widget class="QDoubleSpinBox" name="edgeLength_dspinbox">
+        <property name="minimumSize">
+         <size>
+          <width>110</width>
+          <height>0</height>
+         </size>
         </property>
-        <property name="checked">
-         <bool>false</bool>
+        <property name="maximum">
+         <double>1000.000000000000000</double>
+        </property>
+        <property name="singleStep">
+         <double>0.100000000000000</double>
         </property>
        </widget>
       </item>
-      <item row="1" column="0">
+      <item row="2" column="0">
        <widget class="QLabel" name="nbIterations_label">
         <property name="text">
          <string>Number of Main iterations</string>
@@ -80,7 +106,7 @@
         </property>
        </widget>
       </item>
-      <item row="2" column="0">
+      <item row="3" column="0">
        <spacer name="verticalSpacer_3">
         <property name="orientation">
          <enum>Qt::Vertical</enum>
@@ -96,22 +122,6 @@
         </property>
        </spacer>
       </item>
-      <item row="0" column="1">
-       <widget class="QDoubleSpinBox" name="edgeLength_dspinbox">
-        <property name="minimumSize">
-         <size>
-          <width>110</width>
-          <height>0</height>
-         </size>
-        </property>
-        <property name="maximum">
-         <double>1000.000000000000000</double>
-        </property>
-        <property name="singleStep">
-         <double>0.100000000000000</double>
-        </property>
-       </widget>
-      </item>
       <item row="0" column="0">
        <widget class="QLabel" name="edgeLength_label">
         <property name="text">
@@ -126,22 +136,19 @@
        </widget>
       </item>
       <item row="4" column="1">
-       <widget class="QCheckBox" name="smoothEdges_checkBox">
-        <property name="toolTip">
-         <string extracomment="Smoothing of constrained polylines.\nWarning : this may reduce quality of dihedral angles."/>
-        </property>
+       <widget class="QCheckBox" name="protect_checkbox">
         <property name="text">
-         <string>Smooth constrained edges</string>
+         <string>Protect boundaries</string>
+        </property>
+        <property name="checked">
+         <bool>false</bool>
         </property>
        </widget>
       </item>
-      <item row="3" column="0">
-       <widget class="QLabel" name="options_label">
+      <item row="0" column="2">
+       <widget class="QCheckBox" name="adaptiveSizing_checkbox">
         <property name="text">
-         <string>Options :</string>
-        </property>
-        <property name="alignment">
-         <set>Qt::AlignRight|Qt::AlignTrailing|Qt::AlignVCenter</set>
+         <string>Adaptive</string>
         </property>
        </widget>
       </item>

Lab/demo/Lab/Plugins/Tetrahedral_remeshing/Tetrahedral_remeshing_plugin.cpp

@@ -14,6 +14,7 @@
 
 #include <CGAL/tetrahedral_remeshing.h>
 #include <CGAL/Tetrahedral_remeshing/internal/tetrahedral_remeshing_helpers.h>
+#include <CGAL/Adaptive_remeshing_sizing_field.h>
 
 #include <unordered_map>
 #include <memory>
@@ -98,10 +99,11 @@ public Q_SLOTS:
         std::cout << "Remeshing aborted" << std::endl;
         return;
       }
-      double target_length = ui.edgeLength_dspinbox->value();
-      unsigned int nb_iter = ui.nbIterations_spinbox->value();
-      bool protect = ui.protect_checkbox->isChecked();
-      bool smooth_edges = ui.smoothEdges_checkBox->isChecked();
+      const double target_length = ui.edgeLength_dspinbox->value();
+      const bool adaptive_sizing = ui.adaptiveSizing_checkbox->isChecked();
+      const unsigned int nb_iter = ui.nbIterations_spinbox->value();
+      const bool protect = ui.protect_checkbox->isChecked();
+      const bool smooth_edges = ui.smoothEdges_checkBox->isChecked();
 
       // collect constraints
       using Vertex_handle = Tr::Vertex_handle;
@@ -126,15 +128,27 @@ public Q_SLOTS:
         }
       }
 
-      CGAL::tetrahedral_isotropic_remeshing(
-        c3t3_item->c3t3(),
-        target_length,
-        CGAL::parameters::remesh_boundaries(!protect)
-        .number_of_iterations(nb_iter)
-        .smooth_constrained_edges(smooth_edges)
-        .edge_is_constrained_map(Constraints_pmap(constraints))
-      );
-
+      if (adaptive_sizing)
+      {
+        CGAL::tetrahedral_isotropic_remeshing(
+          c3t3_item->c3t3(),
+          CGAL::create_adaptive_remeshing_sizing_field(c3t3_item->c3t3().triangulation(),
+              CGAL::parameters::edge_is_constrained_map(Constraints_pmap(constraints))),
+          CGAL::parameters::remesh_boundaries(!protect)
+          .number_of_iterations(nb_iter)
+          .smooth_constrained_edges(smooth_edges)
+          .edge_is_constrained_map(Constraints_pmap(constraints))
+        );
+      }
+      else
+      {
+        CGAL::tetrahedral_isotropic_remeshing(
+          c3t3_item->c3t3(),
+          target_length,
+          CGAL::parameters::remesh_boundaries(!protect)
+          .number_of_iterations(nb_iter)
+          .smooth_constrained_edges(smooth_edges));
+      }
       std::cout << "Remeshing done (" << time.elapsed() << " ms)" << std::endl;
 
       c3t3_item->invalidateOpenGLBuffers();
@@ -215,6 +229,7 @@ public Q_SLOTS:
     ui.edgeLength_dspinbox->setRange(1e-6 * diago_length, //min
                                      2.   * diago_length);//max
     ui.edgeLength_dspinbox->setValue(0.05 * diago_length);
+    ui.adaptiveSizing_checkbox->setChecked(false);
 
     std::ostringstream oss;
     oss << "Diagonal length of the Bbox of the triangulation to remesh is ";
@@ -231,6 +246,8 @@ public Q_SLOTS:
 
     connect(ui.protect_checkbox, SIGNAL(toggled(bool)),
             ui.smoothEdges_checkBox, SLOT(setDisabled(bool)));
+    connect(ui.adaptiveSizing_checkbox, SIGNAL(toggled(bool)),
+            ui.edgeLength_dspinbox, SLOT(setDisabled(bool)));
 
     return ui;
   }

SMDS_3/include/CGAL/SMDS_3/io_signature.h

@@ -148,6 +148,15 @@ struct Get_io_signature<double>
   }
 };
 
+template <typename T>
+struct Get_io_signature<std::variant<T> >
+{
+  std::string operator()() {
+    return std::string("std::variant<") +
+      Get_io_signature<T>()() + ">";
+  }
+};
+
 template <typename T, typename U>
 struct Get_io_signature<std::variant<T,U> >
 {

SMDS_3/include/CGAL/facets_in_complex_3_to_triangle_mesh.h

@@ -59,23 +59,28 @@ void facets_in_complex_3_to_triangle_soup(const C3T3& c3t3,
                                           const bool normals_point_outside_of_the_subdomain = true,
                                           const bool export_all_facets = false)
 {
-  typedef typename PointContainer::value_type                            Point_3;
+  typedef typename PointContainer::value_type                            Range_point;
   typedef typename FaceContainer::value_type                             Face;
 
   typedef typename C3T3::Triangulation                                   Tr;
   typedef typename C3T3::Surface_patch_index                             Surface_patch_index;
 
   typedef typename Tr::Cell_handle                                       Cell_handle;
-  typedef typename Tr::Weighted_point                                    Weighted_point;
   typedef typename Tr::Facet                                             Facet;
 
-  typedef std::unordered_map<Point_3, std::size_t>                       PIM;
+  typedef std::unordered_map<Range_point, std::size_t>                   PIM;
 
   typedef typename C3T3::size_type                                       size_type;
 
   // triangulation point to range point
-  CGAL::Cartesian_converter<typename CGAL::Kernel_traits<typename Tr::Geom_traits::Point_3>::type,
-                            typename CGAL::Kernel_traits<Point_3>::type> t2r;
+  using Tr_Bare_point = typename Tr::Geom_traits::Point_3;
+  using Tr_kernel = typename CGAL::Kernel_traits<Tr_Bare_point>::type;
+  using Range_kernel = typename CGAL::Kernel_traits<Range_point>::type;
+
+  using CC = CGAL::Cartesian_converter<Tr_kernel, Range_kernel>;
+  using Id = CGAL::Identity<Range_point>;
+  using T2R = typename std::conditional<std::is_same<Tr_kernel, Range_kernel>::value, Id, CC>::type;
+  T2R tr_to_range;
 
   size_type nf = c3t3.number_of_facets_in_complex();
   faces.reserve(faces.size() + nf);
@@ -87,26 +92,29 @@ void facets_in_complex_3_to_triangle_soup(const C3T3& c3t3,
 
   for(Facet fit : c3t3.facets_in_complex())
   {
-    Cell_handle c = fit.first;
-    int s = fit.second;
+    const Cell_handle c = fit.first;
+    const int s = fit.second;
     const Surface_patch_index spi = c->surface_patch_index(s);
-    Face f;
-    resize(f, 3);
 
-    typename C3T3::Subdomain_index cell_sdi = c3t3.subdomain_index(c);
-    typename C3T3::Subdomain_index opp_sdi = c3t3.subdomain_index(c->neighbor(s));
+    const typename C3T3::Subdomain_index cell_sdi = c3t3.subdomain_index(c);
+    const typename C3T3::Subdomain_index opp_sdi = c3t3.subdomain_index(c->neighbor(s));
 
     if(!export_all_facets && cell_sdi != sd_index && opp_sdi != sd_index)
       continue;
 
-    for(std::size_t i=1; i<4; ++i)
+    Face f;
+    resize(f, 3);
+
+    std::size_t i = 0;
+    for(typename Tr::Vertex_handle v : c3t3.triangulation().vertices(Facet(c, s)))
     {
-      CGAL_assertion_code(typedef typename Tr::Vertex_handle Vertex_handle;)
-      CGAL_assertion_code(Vertex_handle v = c->vertex((s+i)&3);)
-      CGAL_assertion(v != Vertex_handle() && !c3t3.triangulation().is_infinite(v));
+      CGAL_assertion(v != typename Tr::Vertex_handle());
+      CGAL_assertion(!c3t3.triangulation().is_infinite(v));
 
-      const Weighted_point& wp = c3t3.triangulation().point(c, (s+i)&3);
-      const Point_3& bp = t2r(c3t3.triangulation().geom_traits().construct_point_3_object()(wp));
+      const typename Tr::Point tr_wp = c3t3.triangulation().point(v);
+      const typename Tr_kernel::Point_3
+        tr_bp = c3t3.triangulation().geom_traits().construct_point_3_object()(tr_wp);
+      const Range_point bp = tr_to_range(tr_bp);
 
       auto insertion_res = p_to_ids.emplace(bp, inum);
       if(insertion_res.second) // new point
@@ -115,7 +123,7 @@ void facets_in_complex_3_to_triangle_soup(const C3T3& c3t3,
         ++inum;
       }
 
-      f[i-1] = insertion_res.first->second;
+      f[i++] = insertion_res.first->second;
     }
 
     if(export_all_facets)

STL_Extension/include/CGAL/STL_Extension/internal/parameters_interface.h

@@ -245,6 +245,7 @@ CGAL_add_named_parameter(remesh_boundaries_t, remesh_boundaries, remesh_boundari
 CGAL_add_named_parameter(cell_selector_t, cell_selector, cell_is_selected_map)
 CGAL_add_named_parameter(facet_is_constrained_t, facet_is_constrained, facet_is_constrained_map)
 CGAL_add_named_parameter(smooth_constrained_edges_t, smooth_constrained_edges, smooth_constrained_edges)
+CGAL_add_named_parameter(nb_flip_smooth_iterations_t, nb_flip_smooth_iterations, nb_flip_smooth_iterations)
 
 // List of named parameters used in Alpha_wrap_3
 CGAL_add_named_parameter(do_enforce_manifoldness_t, do_enforce_manifoldness, do_enforce_manifoldness)

Spatial_searching/doc/Spatial_searching/CGAL/Kd_tree.h

@@ -99,14 +99,20 @@ Constructs an empty `k-d` tree.
 Kd_tree(Splitter s=Splitter(),Traits t=Traits());
 
 /*!
-
 Constructs a `k-d` tree on the elements from the sequence
 `[first, beyond)` using the splitting rule implemented by `s`.
 The value type of the `InputIterator` must be `Point_d`.
-
 */
 template <class InputIterator> Kd_tree(InputIterator first, InputIterator beyond, Splitter s=Splitter(),Traits t=Traits());
 
+/*!
+Constructs a `k-d` tree on the elements from the range `points`
+using the splitting rule implemented by `s`.
+The value type of elements in `PointRange` must be `Point_d`.
+*/
+template <class PointRange>
+Kd_tree(const PointRange& points, Splitter s = Splitter(), const Traits t = Traits());
+
 /*!
 The constructor does not build the internal data structure, and it
 is also not updated after calls to `insert()`.

Spatial_searching/include/CGAL/Kd_tree.h

@@ -287,6 +287,15 @@ class Kd_tree {
     : traits_(traits), split(s), pts(first, beyond), built_(false)
   { }
 
+  template <class PointRange>
+  Kd_tree(const PointRange& points,
+          Splitter s = Splitter(), const SearchTraits traits = SearchTraits())
+    : traits_(traits),
+      split(s),
+      pts(std::begin(points), std::end(points)),
+      built_(false)
+  { }
+
   bool empty() const {
     return pts.empty();
   }