hub/city_model_structure/attributes/polyhedron.py

"""
Polyhedron module
SPDX - License - Identifier: LGPL - 3.0 - or -later
Copyright © 2020 Project Author Guille Gutierrez guillermo.gutierrezmorote@concordia.ca
"""
import numpy as np
from trimesh import Trimesh
from helpers.geometry_helper import GeometryHelper
from helpers.configuration_helper import ConfigurationHelper
from city_model_structure.attributes.surface import Surface


class Polyhedron:
  """
  Polyhedron class
  """

  def __init__(self, surfaces):
    self._surfaces = list(surfaces)
    self._polygons = [s.polygon for s in surfaces]
    self._polyhedron = None
    self._volume = None
    self._faces = None
    self._vertices = None
    self._mesh = None
    self._centroid = None
    self._max_z = None
    self._max_y = None
    self._max_x = None
    self._min_z = None
    self._min_y = None
    self._min_x = None
    self._geometry = GeometryHelper(delta=0.0, area_delta=0.5)

  def _position_of(self, point, face):
    vertices = self.vertices
    for i in range(len(vertices)):
      # ensure not duplicated vertex
      if i not in face and self._geometry.almost_equal(vertices[i], point):
        return i
    return -1

  @property
  def vertices(self) -> np.ndarray:
    """
    Polyhedron vertices
    :return: np.ndarray(int)
    """
    if self._vertices is None:
      vertices, self._vertices = [], []
      _ = [vertices.extend(s.points) for s in self._surfaces]
      for vertex_1 in vertices:
        found = False
        for vertex_2 in self._vertices:
          found = False
          if self._geometry.almost_equal(vertex_1, vertex_2):
            found = True
            break
        if not found:
          self._vertices.append(vertex_1)
      self._vertices = np.asarray(self._vertices)
    return self._vertices

  @staticmethod
  def _point(coordinates):
    return coordinates[0], coordinates[1], coordinates[2]

  def _triangulate(self, surface):
    triangles = []
    triangles_count = len(surface.points) - 2
    points_list = surface.points_list
    point_index = 0
    area = surface.area
    while len(triangles) < triangles_count:
      # select a triangle starting at point index
      triangle_points = ' '.join(str(e) for e in [*points_list[point_index:point_index + 9]])
      # remove the middle vertex from previous triangle
      rest_points = ' '.join(str(e) for e in [*points_list[0:point_index+3], *points_list[point_index+6:]])
      triangular_surface = Surface(triangle_points, remove_last=False)
      rest_surface = Surface(rest_points, remove_last=False)
      if self._geometry.almost_same_area(area, (triangular_surface.area + rest_surface.area)):
        area = rest_surface.area
        triangles.append(triangular_surface)
        points_list = rest_surface.points_list
        if len(rest_surface.points) == 3:
          triangles.append(rest_surface)
        point_index = 0
      else:
        point_index = point_index + 3
    return triangles

  @property
  def faces(self) -> [[int]]:
    """
    Polyhedron faces
    :return: [[int]]
    """
    if self._faces is None:
      self._faces = []
      for surface in self._surfaces:
        face = []
        points = surface.points
        if len(points) != 3:
          sub_surfaces = self._triangulate(surface)
          for sub_surface in sub_surfaces:
            face = []
            points = sub_surface.points
            for point in points:
              face.append(self._position_of(point, face))
            self._faces.append(face)
        else:
          for point in points:
            face.append(self._position_of(point, face))
          self._faces.append(face)
    return self._faces

  @property
  def _polyhedron_mesh(self):
    if self._mesh is None:
      self._mesh = Trimesh(vertices=self.vertices, faces=self.faces)
    return self._mesh

  @property
  def volume(self):
    """
    Polyhedron volume in cubic meters
    :return: float
    """
    if self._volume is None:
      if not self._polyhedron_mesh.is_volume:
        self._volume = np.inf
      else:
        self._volume = self._polyhedron_mesh.volume
    return self._volume

  @property
  def max_z(self):
    """
    Polyhedron maximal z value
    :return: float
    """
    if self._max_z is None:
      self._max_z = ConfigurationHelper().min_coordinate
      for surface in self._surfaces:
        for point in surface.points:
          if self._max_z < point[2]:
            self._max_z = point[2]
    return self._max_z

  @property
  def max_y(self):
    """
    Polyhedron maximal y value
    :return: float
    """
    if self._max_y is None:
      self._max_y = ConfigurationHelper().min_coordinate
      for surface in self._surfaces:
        for point in surface.points:
          if self._max_y < point[1]:
            self._max_y = point[1]
    return self._max_y

  @property
  def max_x(self):
    """
    Polyhedron maximal x value
    :return: float
    """
    if self._max_x is None:
      self._max_x = ConfigurationHelper().min_coordinate
      for surface in self._surfaces:
        for point in surface.points:
          self._max_x = max(self._max_x, point[0])
    return self._max_x

  @property
  def min_z(self):
    """
    Polyhedron minimal z value
    :return: float
    """
    if self._min_z is None:
      self._min_z = self.max_z
      for surface in self._surfaces:
        for point in surface.points:
          if self._min_z > point[2]:
            self._min_z = point[2]
    return self._min_z

  @property
  def min_y(self):
    """
    Polyhedron minimal y value
    :return: float
    """
    if self._min_y is None:
      self._min_y = self.max_y
      for surface in self._surfaces:
        for point in surface.points:
          if self._min_y > point[1]:
            self._min_y = point[1]
    return self._min_y

  @property
  def min_x(self):
    """
    Polyhedron minimal x value
    :return: float
    """
    if self._min_x is None:
      self._min_x = self.max_x
      for surface in self._surfaces:
        for point in surface.points:
          if self._min_x > point[0]:
            self._min_x = point[0]
    return self._min_x

  @property
  def centroid(self):
    """
    Polyhedron centroid
    :return: [x,y,z]
    """
    return [self.max_x - self.min_x, self.max_y - self.min_y, self.max_z - self.min_z]

  def stl_export(self, full_path):
    """
    Export the polyhedron to stl given file
    :param full_path: str
    :return: None
    """
    self._polyhedron_mesh.export(full_path, 'stl_ascii')

  def obj_export(self, full_path):
    """
    Export the polyhedron to obj given file
    :param full_path: str
    :return: None
    """
    self._polyhedron_mesh.export(full_path, 'obj')

  def show(self):
    self._polyhedron_mesh.show()