system_assignation/city_model_structure/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
import stl
from helpers.geometry import Geometry


class Polyhedron:
  def __init__(self, surfaces):
    self._surfaces = [s for s in 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._geometry = Geometry()

  def _position_of(self, point):
    vertices = self.vertices
    for i in range(len(vertices)):
      if self._geometry.almost_equal(vertices[i], point):
        return i
    return -1

  @property
  def vertices(self):
    if self._vertices is None:
      vertices, self._vertices = [], []
      [vertices.extend(s.points) for s in self._surfaces]
      for v1 in vertices:
        found = False
        for v2 in self._vertices:
          found = False
          if self._geometry.almost_equal(v1, v2):
            found = True
            break
        if not found:
          self._vertices.append(v1)
      self._vertices = np.asarray(self._vertices)
    return self._vertices

  @property
  def faces(self):
    if self._faces is None:
      self._faces = []
      for s in self._surfaces:
        face = []
        points = s.points
        for p in points:
          face.append(self._position_of(p))
        self._faces.append(face)
      self._faces = np.asarray(self._faces)
    return self._faces

  @property
  def _polyhedron_mesh(self):
    if self._mesh is None:
      self._mesh = stl.mesh.Mesh(np.zeros(self.faces.shape[0], dtype=stl.mesh.Mesh.dtype))
      for i, f in enumerate(self.faces):
        for j in range(3):
          self._mesh.vectors[i][j] = self.vertices[f[j], :]
    return self._mesh

  @property
  def volume(self):
    if self._volume is None:
      self._volume, cog, inertia = self._polyhedron_mesh.get_mass_properties()
    return self._volume

  @property
  def max_z(self):
    return self._polyhedron_mesh.z.max()

  def save(self, full_path):
    self._polyhedron_mesh.save(full_path)