summer_course_2024/city_model_structure/attributes/polygon.py
2021-08-26 13:27:43 -04:00

647 lines
24 KiB
Python

"""
Polygon module
SPDX - License - Identifier: LGPL - 3.0 - or -later
Copyright © 2020 Project Author Pilar Monsalvete Alvarez de Uribarri pilar.monsalvete@concordia.ca
"""
from __future__ import annotations
import math
import sys
from typing import List
import numpy as np
from trimesh import Trimesh
import trimesh.intersections
from city_model_structure.attributes.point import Point
class Polygon:
"""
Polygon class
"""
def __init__(self, coordinates):
self._area = None
self._points = None
self._points_list = None
self._normal = None
self._inverse = None
self._edges = None
self._coordinates = coordinates
self._triangles = None
self._vertices = None
self._faces = None
@property
def points(self) -> List[Point]:
"""
List of points belonging to the polygon [[x, y, z],...]
:return: List[Point]
"""
if self._points is None:
self._points = []
for coordinate in self.coordinates:
self._points.append(Point(coordinate))
return self._points
@property
def coordinates(self) -> List[np.ndarray]:
"""
List of points in the shape of its coordinates belonging to the polygon [[x, y, z],...]
:return: [np.ndarray]
"""
return self._coordinates
@property
def points_list(self) -> np.ndarray:
"""
Solid surface point coordinates list [x, y, z, x, y, z,...]
:return: np.ndarray
"""
if self._points_list is None:
s = self.coordinates
self._points_list = np.reshape(s, len(s) * 3)
return self._points_list
@property
def edges(self):
"""
Polygon edges list
"""
if self._edges is None:
self._edges = []
for i in range(0, len(self.points)-1):
point_1 = self.points[i]
point_2 = self.points[i+1]
self._edges.append([point_1, point_2])
self._edges.append([self.points[len(self.points)-1], self.points[0]])
return self._edges
@property
def area(self):
"""
Surface area in square meters
:return: float
"""
# New method to calculate area
if self._area is None:
if len(self.points) < 3:
sys.stderr.write('Warning: the area of a line or point cannot be calculated 1. Area = 0\n')
return 0
alpha = 0
vec_1 = self.points[1].coordinates - self.points[0].coordinates
for i in range(2, len(self.points)):
vec_2 = self.points[i].coordinates - self.points[0].coordinates
alpha += self._angle_between_vectors(vec_1, vec_2)
if alpha == 0:
sys.stderr.write('Warning: the area of a line or point cannot be calculated 2. Area = 0\n')
return 0
horizontal_points = self._points_rotated_to_horizontal
area = 0
for i in range(0, len(horizontal_points)-1):
point = horizontal_points[i]
next_point = horizontal_points[i+1]
area += (next_point[1] + point[1]) / 2 * (next_point[0] - point[0])
next_point = horizontal_points[0]
point = horizontal_points[len(horizontal_points)-1]
area += (next_point[1] + point[1]) / 2 * (next_point[0] - point[0])
self._area = abs(area)
return self._area
@property
def _points_rotated_to_horizontal(self):
"""
polygon points rotated to horizontal
:return: [float]
"""
z_vector = [0, 0, 1]
normal_vector = self.normal
horizontal_points = []
x = normal_vector[0]
y = normal_vector[1]
if x == 0 and y == 0:
# Already horizontal
for point in self.points:
horizontal_points.append([point.coordinates[0], point.coordinates[1], 0])
else:
alpha = self._angle_between_vectors(normal_vector, z_vector)
rotation_line = np.cross(normal_vector, z_vector)
third_axis = np.cross(normal_vector, rotation_line)
w_1 = rotation_line / np.linalg.norm(rotation_line)
w_2 = normal_vector
w_3 = third_axis / np.linalg.norm(third_axis)
rotation_matrix = np.array([[1, 0, 0],
[0, np.cos(alpha), -np.sin(alpha)],
[0, np.sin(alpha), np.cos(alpha)]])
base_matrix = np.array([w_1, w_2, w_3])
rotation_base_matrix = np.matmul(base_matrix.transpose(), rotation_matrix.transpose())
rotation_base_matrix = np.matmul(rotation_base_matrix, base_matrix)
if rotation_base_matrix is None:
sys.stderr.write('Warning: rotation base matrix returned None\n')
else:
for point in self.points:
new_point = np.matmul(rotation_base_matrix, point.coordinates)
horizontal_points.append(new_point)
return horizontal_points
@property
def normal(self) -> np.ndarray:
"""
Surface normal vector
:return: np.ndarray
"""
if self._normal is None:
points = self.coordinates
# todo: IF THE FIRST ONE IS 0, START WITH THE NEXT
point_origin = points[len(points)-2]
vector_1 = points[len(points)-1] - point_origin
vector_2 = points[0] - point_origin
vector_3 = points[1] - point_origin
cross_product = np.cross(vector_1, vector_2)
if np.linalg.norm(cross_product) != 0:
cross_product = cross_product / np.linalg.norm(cross_product)
alpha = self._angle_between_vectors(vector_1, vector_2)
else:
cross_product = [0, 0, 0]
alpha = 0
if len(points) == 3:
return cross_product
if np.linalg.norm(cross_product) == 0:
return cross_product
alpha += self._angle(vector_2, vector_3, cross_product)
for i in range(0, len(points)-4):
vector_1 = points[i+1] - point_origin
vector_2 = points[i+2] - point_origin
alpha += self._angle(vector_1, vector_2, cross_product)
vector_1 = points[len(points) - 1] - point_origin
vector_2 = points[0] - point_origin
if alpha < 0:
cross_product = np.cross(vector_2, vector_1)
else:
cross_product = np.cross(vector_1, vector_2)
self._normal = cross_product / np.linalg.norm(cross_product)
return self._normal
@staticmethod
def _angle(vector_1, vector_2, cross_product):
"""
alpha angle in radians
:param vector_1: [float]
:param vector_2: [float]
:param cross_product: [float]
:return: float
"""
accepted_normal_difference = 0.01
cross_product_next = np.cross(vector_1, vector_2)
if np.linalg.norm(cross_product_next) != 0:
cross_product_next = cross_product_next / np.linalg.norm(cross_product_next)
alpha = Polygon._angle_between_vectors(vector_1, vector_2)
else:
cross_product_next = [0, 0, 0]
alpha = 0
delta_normals = 0
for j in range(0, 3):
delta_normals += cross_product[j] - cross_product_next[j]
if np.abs(delta_normals) < accepted_normal_difference:
return alpha
return -alpha
def triangulate(self) -> List[Polygon]:
"""
triangulates a polygon following the ear clipping methodology
:return: list[triangles]
"""
# todo: review triangulate_polygon in
# https://github.com/mikedh/trimesh/blob/dad11126742e140ef46ba12f8cb8643c83356467/trimesh/creation.py#L415,
# it had a problem with a class called 'triangle', but, if solved,
# it could be a very good substitute of this method
# this method is very dirty and has an infinite loop solved with a counter!!
if self._triangles is None:
points_list = self.points_list
normal = self.normal
if np.linalg.norm(normal) == 0:
sys.stderr.write('Not able to triangulate polygon\n')
return [self]
# are points concave or convex?
total_points_list, concave_points, convex_points = self._starting_lists(points_list, normal)
# list of ears
ears = []
j = 0
while (len(concave_points) > 3 or len(convex_points) != 0) and j < 100:
j += 1
for i in range(0, len(concave_points)):
ear = self._triangle(points_list, total_points_list, concave_points[i])
rest_points = []
for points in total_points_list:
rest_points.append(list(self.coordinates[points]))
if self._is_ear(ear, rest_points):
ears.append(ear)
point_to_remove = concave_points[i]
previous_point_in_list, next_point_in_list = self._enveloping_points(point_to_remove, total_points_list)
total_points_list.remove(point_to_remove)
concave_points.remove(point_to_remove)
# Was any of the adjacent points convex? -> check if changed status to concave
for convex_point in convex_points:
if convex_point == previous_point_in_list:
concave_points, convex_points, end_loop = self._if_concave_change_status(normal, points_list,
convex_point,
total_points_list,
concave_points, convex_points,
previous_point_in_list)
if end_loop:
break
continue
if convex_point == next_point_in_list:
concave_points, convex_points, end_loop = self._if_concave_change_status(normal, points_list,
convex_point,
total_points_list,
concave_points, convex_points,
next_point_in_list)
if end_loop:
break
continue
break
if len(total_points_list) <= 3 and len(convex_points) > 0:
sys.stderr.write('Not able to triangulate polygon\n')
return [self]
if j >= 100:
sys.stderr.write('Not able to triangulate polygon\n')
return [self]
last_ear = self._triangle(points_list, total_points_list, concave_points[1])
ears.append(last_ear)
self._triangles = ears
return self._triangles
@staticmethod
def _starting_lists(points_list, normal) -> [List[float], List[float], List[float]]:
"""
creates the list of vertices (points) that define the polygon (total_points_list), together with other two lists
separating points between convex and concave
:param points_list: points_list
:param normal: normal
:return: list[point], list[point], list[point]
"""
concave_points = []
convex_points = []
# lists of concave and convex points
# case 1: first point
point = points_list[0:3]
previous_point = points_list[len(points_list) - 3:]
next_point = points_list[3:6]
index = 0
total_points_list = [index]
if Polygon._point_is_concave(normal, point, previous_point, next_point):
concave_points.append(index)
else:
convex_points.append(index)
# case 2: all points except first and last
for i in range(0, int((len(points_list)-6)/3)):
point = points_list[(i+1)*3:(i+2)*3]
previous_point = points_list[i*3:(i+1)*3]
next_point = points_list[(i+2)*3:(i+3)*3]
index = i+1
total_points_list.append(index)
if Polygon._point_is_concave(normal, point, previous_point, next_point):
concave_points.append(index)
else:
convex_points.append(index)
# case 3: last point
point = points_list[len(points_list) - 3:]
previous_point = points_list[len(points_list) - 6:len(points_list) - 3]
next_point = points_list[0:3]
index = int(len(points_list)/3) - 1
total_points_list.append(index)
if Polygon._point_is_concave(normal, point, previous_point, next_point):
concave_points.append(index)
else:
convex_points.append(index)
return total_points_list, concave_points, convex_points
@staticmethod
def _triangle(points_list, total_points_list, point_position) -> Polygon:
"""
creates a triangular polygon out of three points
:param points_list: points_list
:param total_points_list: [point]
:param point_position: int
:return: polygon
"""
index = point_position * 3
previous_point_index, next_point_index = Polygon._enveloping_points_indices(point_position, total_points_list)
points = points_list[previous_point_index:previous_point_index + 3]
points = np.append(points, points_list[index:index + 3])
points = np.append(points, points_list[next_point_index:next_point_index + 3])
rows = points.size // 3
points = points.reshape(rows, 3)
triangle = Polygon(points)
return triangle
@staticmethod
def _enveloping_points_indices(point_position, total_points_list):
"""
due to the fact that the lists are not circular, a method to find the previous and next points
of an specific one is needed
:param point_position: int
:param total_points_list: [point]
:return: int, int
"""
previous_point_index = None
next_point_index = None
if point_position == total_points_list[0]:
previous_point_index = total_points_list[len(total_points_list) - 1] * 3
next_point_index = total_points_list[1] * 3
if point_position == total_points_list[len(total_points_list) - 1]:
previous_point_index = total_points_list[len(total_points_list) - 2] * 3
next_point_index = total_points_list[0] * 3
for i in range(1, len(total_points_list)-1):
if point_position == total_points_list[i]:
previous_point_index = total_points_list[i - 1] * 3
next_point_index = total_points_list[i + 1] * 3
return previous_point_index, next_point_index
@staticmethod
def _enveloping_points(point_to_remove, total_points_list):
"""
due to the fact that the lists are not circular, a method to find the previous and next points
of an specific one is needed
:param point_to_remove: point
:param total_points_list: [point]
:return: point, point
"""
index = total_points_list.index(point_to_remove)
if index == 0:
previous_point_in_list = total_points_list[len(total_points_list) - 1]
next_point_in_list = total_points_list[1]
elif index == len(total_points_list) - 1:
previous_point_in_list = total_points_list[len(total_points_list) - 2]
next_point_in_list = total_points_list[0]
else:
previous_point_in_list = total_points_list[index - 1]
next_point_in_list = total_points_list[index + 1]
return previous_point_in_list, next_point_in_list
@staticmethod
def _is_ear(ear, points) -> bool:
"""
finds whether a triangle is an ear of the polygon
:param ear: polygon
:param points: [point]
:return: boolean
"""
area_ear = ear.area
for point in points:
area_points = 0
point_is_not_vertex = True
for i in range(0, 3):
if abs(np.linalg.norm(point) - np.linalg.norm(ear.coordinates[i])) < 0.0001:
point_is_not_vertex = False
break
if point_is_not_vertex:
for i in range(0, 3):
if i != 2:
new_points = ear.coordinates[i][:]
new_points = np.append(new_points, ear.coordinates[i + 1][:])
new_points = np.append(new_points, point[:])
else:
new_points = ear.coordinates[i][:]
new_points = np.append(new_points, point[:])
new_points = np.append(new_points, ear.coordinates[0][:])
rows = new_points.size // 3
new_points = new_points.reshape(rows, 3)
new_triangle = Polygon(new_points)
area_points += new_triangle.area
if abs(area_points - area_ear) < 1e-6:
# point_inside_ear = True
return False
return True
@staticmethod
def _if_concave_change_status(normal, points_list, convex_point, total_points_list,
concave_points, convex_points, point_in_list) -> [List[float], List[float], bool]:
"""
checks whether an convex specific point change its status to concave after removing one ear in the polygon
returning the new convex and concave points lists together with a flag advising that the list of total points
already 3 and, therefore, the triangulation must be finished.
:param normal: normal
:param points_list: points_list
:param convex_point: int
:param total_points_list: [point]
:param concave_points: [point]
:param convex_points: [point]
:param point_in_list: int
:return: list[points], list[points], boolean
"""
end_loop = False
point = points_list[point_in_list * 3:(point_in_list + 1) * 3]
pointer = total_points_list.index(point_in_list) - 1
if pointer < 0:
pointer = len(total_points_list) - 1
previous_point = points_list[total_points_list[pointer] * 3:total_points_list[pointer] * 3 + 3]
pointer = total_points_list.index(point_in_list) + 1
if pointer >= len(total_points_list):
pointer = 0
next_point = points_list[total_points_list[pointer] * 3:total_points_list[pointer] * 3 + 3]
if Polygon._point_is_concave(normal, point, previous_point, next_point):
if concave_points[0] > convex_point:
concave_points.insert(0, convex_point)
elif concave_points[len(concave_points) - 1] < convex_point:
concave_points.append(convex_point)
else:
for point_index in range(0, len(concave_points) - 1):
if concave_points[point_index] < convex_point < concave_points[point_index + 1]:
concave_points.insert(point_index + 1, convex_point)
convex_points.remove(convex_point)
end_loop = True
return concave_points, convex_points, end_loop
@staticmethod
def _point_is_concave(normal, point, previous_point, next_point) -> bool:
"""
returns whether a point is concave
:param normal: normal
:param point: point
:param previous_point: point
:param next_point: point
:return: boolean
"""
is_concave = False
accepted_error = 0.1
points = np.append(previous_point, point)
points = np.append(points, next_point)
rows = points.size // 3
points = points.reshape(rows, 3)
triangle = Polygon(points)
error_sum = 0
for i in range(0, len(normal)):
error_sum += triangle.normal[i] - normal[i]
if np.abs(error_sum) < accepted_error:
is_concave = True
return is_concave
@staticmethod
def _angle_between_vectors(vec_1, vec_2):
"""
angle between vectors in radians
:param vec_1: vector
:param vec_2: vector
:return: float
"""
if np.linalg.norm(vec_1) == 0 or np.linalg.norm(vec_2) == 0:
sys.stderr.write("Warning: impossible to calculate angle between planes' normal. Return 0\n")
return 0
cosine = np.dot(vec_1, vec_2) / np.linalg.norm(vec_1) / np.linalg.norm(vec_2)
if cosine > 1 and cosine-1 < 1e-5:
cosine = 1
elif cosine < -1 and cosine+1 > -1e-5:
cosine = -1
alpha = math.acos(cosine)
return alpha
@property
def inverse(self):
"""
Flips the order of the coordinates
:return: [np.ndarray]
"""
if self._inverse is None:
self._inverse = self.coordinates[::-1]
return self._inverse
def divide(self, plane):
"""
Divides the polygon in two by a plane
:param plane: plane that intersects with self to divide it in two parts (Plane)
:return: Polygon, Polygon, [Point]
"""
tri_polygons = Trimesh(vertices=self.vertices, faces=self.faces)
intersection = trimesh.intersections.mesh_plane(tri_polygons, plane.normal, plane.origin.coordinates)
polys_1 = trimesh.intersections.slice_mesh_plane(tri_polygons, plane.opposite_normal, plane.origin.coordinates)
polys_2 = trimesh.intersections.slice_mesh_plane(tri_polygons, plane.normal, plane.origin.coordinates)
triangles_1 = []
for triangle in polys_1.triangles:
triangles_1.append(Polygon(triangle))
polygon_1 = self._reshape(triangles_1)
triangles_2 = []
for triangle in polys_2.triangles:
triangles_2.append(Polygon(triangle))
polygon_2 = self._reshape(triangles_2)
return polygon_1, polygon_2, intersection
def _reshape(self, triangles) -> Polygon:
edges_list = []
for i in range(0, len(triangles)):
for edge in triangles[i].edges:
if not self._edge_in_edges_list(edge, edges_list):
edges_list.append(edge)
else:
edges_list = self._remove_from_list(edge, edges_list)
points = self._order_points(edges_list)
return Polygon(points)
@staticmethod
def _edge_in_edges_list(edge, edges_list):
for edge_element in edges_list:
if (edge_element[0].distance_to_point(edge[0]) == 0 and edge_element[1].distance_to_point(edge[1]) == 0) or\
(edge_element[1].distance_to_point(edge[0]) == 0 and edge_element[0].distance_to_point(edge[1]) == 0):
return True
return False
@staticmethod
def _order_points(edges_list):
# todo: not sure that this method works for any case -> RECHECK
points = edges_list[0]
for _ in range(0, len(points)):
for i in range(1, len(edges_list)):
point_1 = edges_list[i][0]
point_2 = points[len(points)-1]
if point_1.distance_to_point(point_2) == 0:
points.append(edges_list[i][1])
points.remove(points[len(points)-1])
array_points = []
for point in points:
array_points.append(point.coordinates)
return np.array(array_points)
@staticmethod
def _remove_from_list(edge, edges_list):
new_list = []
for edge_element in edges_list:
if not((edge_element[0].distance_to_point(edge[0]) == 0 and edge_element[1].distance_to_point(edge[1]) == 0) or
(edge_element[1].distance_to_point(edge[0]) == 0 and edge_element[0].distance_to_point(edge[1]) == 0)):
new_list.append(edge_element)
return new_list
@property
def vertices(self) -> np.ndarray:
"""
Polyhedron vertices
:return: np.ndarray(int)
"""
if self._vertices is None:
vertices, self._vertices = [], []
_ = [vertices.extend(s.coordinates) for s in self.triangulate()]
for vertex_1 in vertices:
found = False
for vertex_2 in self._vertices:
found = False
power = 0
for dimension in range(0, 3):
power += math.pow(vertex_2[dimension] - vertex_1[dimension], 2)
distance = math.sqrt(power)
if distance == 0:
found = True
break
if not found:
self._vertices.append(vertex_1)
self._vertices = np.asarray(self._vertices)
return self._vertices
@property
def faces(self) -> List[List[int]]:
"""
Polyhedron triangular faces
:return: [face]
"""
if self._faces is None:
self._faces = []
for polygon in self.triangulate():
face = []
points = polygon.coordinates
if len(points) != 3:
sub_polygons = polygon.triangulate()
# todo: I modified this! To be checked @Guille
if len(sub_polygons) >= 1:
for sub_polygon in sub_polygons:
face = []
points = sub_polygon.coordinates
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
def _position_of(self, point, face):
"""
position of a specific point in the list of points that define a face
:return: int
"""
vertices = self.vertices
for i in range(len(vertices)):
# ensure not duplicated vertex
power = 0
vertex2 = vertices[i]
for dimension in range(0, 3):
power += math.pow(vertex2[dimension] - point[dimension], 2)
distance = math.sqrt(power)
if i not in face and distance == 0:
return i
return -1