Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Fix #1040. New utility for geometric shape analysis only requiring nu…
…mpy.
- Loading branch information
Showing
1 changed file
with
182 additions
and
0 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,182 @@ | ||
# IfcOpenShell - IFC toolkit and geometry engine | ||
# Copyright (C) 2023 Dion Moult <dion@thinkmoult.com> | ||
# | ||
# This file is part of IfcOpenShell. | ||
# | ||
# IfcOpenShell is free software: you can redistribute it and/or modify | ||
# it under the terms of the GNU Lesser General Public License as published by | ||
# the Free Software Foundation, either version 3 of the License, or | ||
# (at your option) any later version. | ||
# | ||
# IfcOpenShell is distributed in the hope that it will be useful, | ||
# but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
# GNU Lesser General Public License for more details. | ||
# | ||
# You should have received a copy of the GNU Lesser General Public License | ||
# along with IfcOpenShell. If not, see <http://www.gnu.org/licenses/>. | ||
|
||
import numpy as np | ||
|
||
tol = 1e-6 | ||
|
||
|
||
def is_x(value, x): | ||
return abs(x - value) < tol | ||
|
||
|
||
def get_volume(geometry): | ||
def signed_triangle_volume(p1, p2, p3): | ||
v321 = p3[0] * p2[1] * p1[2] | ||
v231 = p2[0] * p3[1] * p1[2] | ||
v312 = p3[0] * p1[1] * p2[2] | ||
v132 = p1[0] * p3[1] * p2[2] | ||
v213 = p2[0] * p1[1] * p3[2] | ||
v123 = p1[0] * p2[1] * p3[2] | ||
return (1.0 / 6.0) * (-v321 + v231 + v312 - v132 - v213 + v123) | ||
|
||
verts = geometry.verts | ||
faces = geometry.faces | ||
grouped_verts = [[verts[i], verts[i + 1], verts[i + 2]] for i in range(0, len(verts), 3)] | ||
volumes = [ | ||
signed_triangle_volume(grouped_verts[faces[i]], grouped_verts[faces[i + 1]], grouped_verts[faces[i + 2]]) | ||
for i in range(0, len(faces), 3) | ||
] | ||
return abs(sum(volumes)) | ||
|
||
|
||
def get_x(geometry): | ||
x_values = [geometry.verts[i] for i in range(0, len(geometry.verts), 3)] | ||
return max(x_values) - min(x_values) | ||
|
||
|
||
def get_y(geometry): | ||
y_values = [geometry.verts[i + 1] for i in range(0, len(geometry.verts), 3)] | ||
return max(y_values) - min(y_values) | ||
|
||
|
||
def get_z(geometry): | ||
z_values = [geometry.verts[i + 2] for i in range(0, len(geometry.verts), 3)] | ||
return max(z_values) - min(z_values) | ||
|
||
|
||
def get_area_vf(vertices, faces): | ||
# Calculate the triangle normal vectors | ||
v1 = vertices[faces[:, 1]] - vertices[faces[:, 0]] | ||
v2 = vertices[faces[:, 2]] - vertices[faces[:, 0]] | ||
triangle_normals = np.cross(v1, v2) | ||
|
||
# Normalize the normal vectors to get their length (i.e., triangle area) | ||
triangle_areas = np.linalg.norm(triangle_normals, axis=1) / 2 | ||
|
||
# Sum up the areas to get the total area of the mesh | ||
mesh_area = np.sum(triangle_areas) | ||
|
||
return mesh_area | ||
|
||
|
||
def get_area(geometry): | ||
verts = geometry.verts | ||
faces = geometry.faces | ||
vertices = np.array([[verts[i], verts[i + 1], verts[i + 2]] for i in range(0, len(verts), 3)]) | ||
faces = np.array([[faces[i], faces[i + 1], faces[i + 2]] for i in range(0, len(faces), 3)]) | ||
return get_area_vf(vertices, faces) | ||
|
||
|
||
def get_side_area(geometry): | ||
verts = geometry.verts | ||
faces = geometry.faces | ||
vertices = np.array([[verts[i], verts[i + 1], verts[i + 2]] for i in range(0, len(verts), 3)]) | ||
faces = np.array([[faces[i], faces[i + 1], faces[i + 2]] for i in range(0, len(faces), 3)]) | ||
|
||
# Calculate the triangle normal vectors | ||
v1 = vertices[faces[:, 1]] - vertices[faces[:, 0]] | ||
v2 = vertices[faces[:, 2]] - vertices[faces[:, 0]] | ||
triangle_normals = np.cross(v1, v2) | ||
|
||
# Normalize the normal vectors | ||
triangle_normals = triangle_normals / np.linalg.norm(triangle_normals, axis=1)[:, np.newaxis] | ||
|
||
# Find the faces with a normal vector pointing in the desired +Y normal direction | ||
filtered_face_indices = np.where(triangle_normals[:, 1] > tol)[0] | ||
filtered_faces = faces[filtered_face_indices] | ||
return get_area_vf(vertices, filtered_faces) | ||
|
||
|
||
def get_footprint_area(geometry): | ||
verts = geometry.verts | ||
faces = geometry.faces | ||
vertices = np.array([[verts[i], verts[i + 1], verts[i + 2]] for i in range(0, len(verts), 3)]) | ||
faces = np.array([[faces[i], faces[i + 1], faces[i + 2]] for i in range(0, len(faces), 3)]) | ||
|
||
# Calculate the triangle normal vectors | ||
v1 = vertices[faces[:, 1]] - vertices[faces[:, 0]] | ||
v2 = vertices[faces[:, 2]] - vertices[faces[:, 0]] | ||
triangle_normals = np.cross(v1, v2) | ||
|
||
# Normalize the normal vectors | ||
triangle_normals = triangle_normals / np.linalg.norm(triangle_normals, axis=1)[:, np.newaxis] | ||
|
||
# Find the faces with a normal vector pointing in the desired +Z normal direction | ||
filtered_face_indices = np.where(triangle_normals[:, 2] > tol)[0] | ||
filtered_faces = faces[filtered_face_indices] | ||
return get_area_vf(vertices, filtered_faces) | ||
|
||
|
||
def get_outer_surface_area(geometry): | ||
verts = geometry.verts | ||
faces = geometry.faces | ||
vertices = np.array([[verts[i], verts[i + 1], verts[i + 2]] for i in range(0, len(verts), 3)]) | ||
faces = np.array([[faces[i], faces[i + 1], faces[i + 2]] for i in range(0, len(faces), 3)]) | ||
|
||
# Calculate the triangle normal vectors | ||
v1 = vertices[faces[:, 1]] - vertices[faces[:, 0]] | ||
v2 = vertices[faces[:, 2]] - vertices[faces[:, 0]] | ||
triangle_normals = np.cross(v1, v2) | ||
|
||
# Normalize the normal vectors | ||
triangle_normals = triangle_normals / np.linalg.norm(triangle_normals, axis=1)[:, np.newaxis] | ||
|
||
# Find the faces with a normal vector that isn't +Z or -Z | ||
filtered_face_indices = np.where(abs(triangle_normals[:, 2]) < tol)[0] | ||
filtered_faces = faces[filtered_face_indices] | ||
return get_area_vf(vertices, filtered_faces) | ||
|
||
|
||
def get_footprint_perimeter(geometry): | ||
verts = geometry.verts | ||
faces = geometry.faces | ||
vertices = np.array([[verts[i], verts[i + 1], verts[i + 2]] for i in range(0, len(verts), 3)]) | ||
faces = np.array([[faces[i], faces[i + 1], faces[i + 2]] for i in range(0, len(faces), 3)]) | ||
|
||
# Calculate the triangle normal vectors | ||
v1 = vertices[faces[:, 1]] - vertices[faces[:, 0]] | ||
v2 = vertices[faces[:, 2]] - vertices[faces[:, 0]] | ||
triangle_normals = np.cross(v1, v2) | ||
|
||
# Normalize the normal vectors | ||
triangle_normals = triangle_normals / np.linalg.norm(triangle_normals, axis=1)[:, np.newaxis] | ||
|
||
# Find the faces with a normal vector pointing in the negative Z direction | ||
negative_z_face_indices = np.where(triangle_normals[:, 2] < -tol)[0] | ||
negative_z_faces = faces[negative_z_face_indices] | ||
|
||
# Initialize the set of counted edges and the perimeter | ||
all_edges = set() | ||
shared_edges = set() | ||
perimeter = 0 | ||
|
||
# Loop through each face | ||
for face in negative_z_faces: | ||
# Loop through each edge of the face | ||
for i in range(3): | ||
# Get the indices of the two vertices that define the edge | ||
edge = (face[i], face[(i + 1) % 3]) | ||
# Keep track of shared edges. Perimeter edges are unshared. | ||
if (edge[1], edge[0]) in all_edges or (edge[0], edge[1]) in all_edges: | ||
shared_edges.add((edge[0], edge[1])) | ||
shared_edges.add((edge[1], edge[0])) | ||
else: | ||
all_edges.add(edge) | ||
|
||
return sum([np.linalg.norm(vertices[e[0]] - vertices[e[1]]) for e in (all_edges - shared_edges)]) |