def assembly_hull(assembly, keys=None, unify=True):
"""Construct the convex hull of an assembly.
Parameters
----------
assembly : Assembly
The assembly data structure.
keys: list, optional
The identifiers of the blocks to include in the hull calculation.
Defaults to all blocks.
unify : bool, optional
Unify the face cycles of the hull.
Default is ``True``.
Returns
-------
tuple
The vertices and faces of the hull.
Examples
--------
.. code-block:: python
import compas_assembly
from compas.datastructures import Mesh
from compas.viewers import MeshViewer
from compas_assembly.datastructures import Assembly
assembly = Assembly.from_json(compas_assembly.get('assembly.json'))
vertices, faces = assembly_hull(assembly)
hull = Mesh.from_vertices_and_faces(vertices, faces)
viewer = MeshViewer()
viewer.mesh = hull
viewer.show()
"""
keys = keys or list(assembly.vertices())
points = []
for key in keys:
block = assembly.blocks[key]
points.extend(block.get_vertices_attributes('xyz'))
faces = convex_hull(points)
vertices = list(set(flatten(faces)))
i_index = {i: index for index, i in enumerate(vertices)}
vertices = [points[index] for index in vertices]
faces = [[i_index[i] for i in face] for face in faces]
if unify:
faces = unify_cycles(vertices, faces)
return vertices, faces
def get_convex_hull_mesh(points):
faces = convex_hull(points)
vertices = list(set(flatten(faces)))
i_index = {i: index for index, i in enumerate(vertices)}
vertices = [points[index] for index in vertices]
faces = [[i_index[i] for i in face] for face in faces]
faces = unify_cycles(vertices, faces)
mesh = Mesh.from_vertices_and_faces(vertices, faces)
return mesh
def assembly_hull_numpy(assembly, keys=None, unify=True):
"""Construct the convex hull of an assembly.
Parameters
----------
assembly : Assembly
The assembly data structure.
keys: list, optional
The identifiers of the blocks to include in the hull calculation.
Defaults to all blocks.
unify : bool, optional
Unify the face cycles of the hull.
Default is ``True``.
Returns
-------
tuple
The vertices and faces of the hull.
Warning
-------
This function requires Numpy and cannot be used directly inside Rhino.
Examples
--------
>>>
"""
keys = keys or list(assembly.nodes())
points = []
for key in keys:
block = assembly.blocks[key]
points.extend(block.vertices_attributes('xyz'))
vertices, faces = convex_hull_numpy(points)
i_index = {i: index for index, i in enumerate(vertices)}
vertices = [points[index] for index in vertices]
faces = [[i_index[i] for i in face] for face in faces]
if unify:
faces = unify_cycles(vertices, faces)
return vertices, faces
radius = 5
origin = (0., 0., 0.)
count = 0
points = []
while count < 1000:
x = (random.random() - 0.5) * radius * 2
y = (random.random() - 0.5) * radius * 2
z = (random.random() - 0.5) * radius * 2
pt = x, y, z
if distance_point_point(origin, pt) <= radius:
points.append(pt)
count += 1
vertices, faces = convex_hull_numpy(points)
i_index = {i: index for index, i in enumerate(vertices)}
vertices = [points[index] for index in vertices]
faces = [[i_index[i] for i in face] for face in faces]
faces = unify_cycles(vertices, faces)
mesh = Mesh.from_vertices_and_faces(vertices, faces)
viewer = MeshViewer()
viewer.mesh = mesh
viewer.show()