Building octree based on distance from mesh

src/libslic3r/Fill/FillAdaptive.cpp

@@ -1,6 +1,8 @@
 #include "../ClipperUtils.hpp"
 #include "../ExPolygon.hpp"
 #include "../Surface.hpp"
+#include "../Geometry.hpp"
+#include "../AABBTreeIndirect.hpp"
 
 #include "FillAdaptive.hpp"
 
@@ -16,4 +18,88 @@ void FillAdaptive::_fill_surface_single(
 
 }
 
+FillAdaptive_Internal::Octree* FillAdaptive::build_octree(
+    TriangleMesh &triangleMesh,
+    coordf_t line_spacing,
+    const BoundingBoxf3 &printer_volume,
+    const Vec3d &cube_center)
+{
+    using namespace FillAdaptive_Internal;
+
+    if(line_spacing <= 0)
+    {
+        return nullptr;
+    }
+
+    // The furthest point from center of bed.
+    double furthest_point = std::sqrt(((printer_volume.size()[0] * printer_volume.size()[0]) / 4.0) +
+                                      ((printer_volume.size()[1] * printer_volume.size()[1]) / 4.0) +
+                                      (printer_volume.size()[2] * printer_volume.size()[2]));
+    double max_cube_edge_length = furthest_point * 2;
+
+    std::vector<CubeProperties> cubes_properties;
+    for (double edge_length = (line_spacing * 2); edge_length < (max_cube_edge_length * 2); edge_length *= 2)
+    {
+        CubeProperties props{};
+        props.edge_length = edge_length;
+        props.height = edge_length * sqrt(3);
+        props.diagonal_length = edge_length * sqrt(2);
+        props.line_z_distance = edge_length / sqrt(3);
+        props.line_xy_distance = edge_length / sqrt(6);
+        cubes_properties.push_back(props);
+    }
+
+    if (triangleMesh.its.vertices.empty())
+    {
+        triangleMesh.require_shared_vertices();
+    }
+
+    Vec3d rotation = Vec3d(Geometry::deg2rad(225.0), Geometry::deg2rad(215.0), Geometry::deg2rad(30.0));
+    Transform3d rotation_matrix = Geometry::assemble_transform(Vec3d::Zero(), rotation, Vec3d::Ones(), Vec3d::Ones());
+
+    AABBTreeIndirect::Tree3f aabbTree = AABBTreeIndirect::build_aabb_tree_over_indexed_triangle_set(triangleMesh.its.vertices, triangleMesh.its.indices);
+    Octree *octree = new Octree{new Cube{cube_center, cubes_properties.size() - 1, cubes_properties.back()}, cube_center};
+
+    FillAdaptive::expand_cube(octree->root_cube, cubes_properties, rotation_matrix, aabbTree, triangleMesh);
+
+    return octree;
+}
+
+void FillAdaptive::expand_cube(
+    FillAdaptive_Internal::Cube *cube,
+    const std::vector<FillAdaptive_Internal::CubeProperties> &cubes_properties,
+    const Transform3d &rotation_matrix,
+    const AABBTreeIndirect::Tree3f &distanceTree,
+    const TriangleMesh &triangleMesh)
+{
+    using namespace FillAdaptive_Internal;
+
+    if (cube == nullptr || cube->depth == 0)
+    {
+        return;
+    }
+
+    std::vector<Vec3d> child_centers = {
+            Vec3d(-1, -1, -1), Vec3d( 1, -1, -1), Vec3d(-1,  1, -1), Vec3d(-1, -1,  1),
+            Vec3d( 1,  1,  1), Vec3d(-1,  1,  1), Vec3d( 1, -1,  1), Vec3d( 1,  1, -1)
+    };
+
+    double cube_radius_squared = (cube->properties.height * cube->properties.height) / 16;
+
+    for (const Vec3d &child_center : child_centers) {
+        Vec3d child_center_transformed = cube->center + rotation_matrix * (child_center * (cube->properties.edge_length / 4));
+        Vec3d closest_point = Vec3d::Zero();
+        size_t closest_triangle_idx = 0;
+
+        double distance_squared = AABBTreeIndirect::squared_distance_to_indexed_triangle_set(
+                triangleMesh.its.vertices, triangleMesh.its.indices, distanceTree, child_center_transformed,
+                closest_triangle_idx,closest_point);
+
+        if(distance_squared <= cube_radius_squared) {
+            cube->children.push_back(new Cube{child_center_transformed, cube->depth - 1, cubes_properties[cube->depth - 1]});
+            FillAdaptive::expand_cube(cube->children.back(), cubes_properties, rotation_matrix, distanceTree, triangleMesh);
+        }
+    }
+}
+
 } // namespace Slic3r