def clip(source_mesh: Mesh, plane: Plane, vicinity_tol=1e-3, name=None):
"""Return a new mesh containing the source mesh clipped by the plane.
Parameters
----------
source_mesh : Mesh
The mesh to be clipped.
plane : Plane, optional
The clipping plane.
vicinity_tol : float, optional
The absolute tolerance to consider en vertex is on the plane. Default is 1e-3.
name: string, optional
A name for the new clipped mesh.
"""
vertices_data = _vertices_positions_wrt_plane(source_mesh, plane,
vicinity_tol)
nb_vertices_above_or_on_plane = np.count_nonzero(
vertices_data['vertices_above_mask']
| vertices_data['vertices_on_mask'])
nb_vertices_below_or_on_plane = np.count_nonzero(
vertices_data['vertices_below_mask']
| vertices_data['vertices_on_mask'])
if nb_vertices_above_or_on_plane == source_mesh.nb_vertices:
LOG.warning(
f"Clipping {source_mesh.name} by {plane}: all vertices are removed."
)
clipped_mesh = Mesh(None, None)
clipped_mesh._clipping_data = dict(faces_ids=[])
elif nb_vertices_below_or_on_plane == source_mesh.nb_vertices:
LOG.info(f"Clipping {source_mesh.name} by {plane}: no action.")
clipped_mesh = source_mesh.copy()
clipped_mesh._clipping_data = dict(
faces_ids=list(range(source_mesh.nb_faces)))
else:
upper_mesh, crown_mesh, lower_mesh = _partition_mesh(
vertices_data, source_mesh)
if crown_mesh.nb_faces > 0:
clipped_crown_mesh = _clip_crown(crown_mesh, plane)
clipped_mesh = lower_mesh + clipped_crown_mesh
clipped_mesh._clipping_data = {
'faces_ids':
np.concatenate(
(lower_mesh._clipping_data['faces_ids'],
clipped_crown_mesh._clipping_data['faces_ids']))
}
else:
clipped_mesh = lower_mesh
if name is None:
clipped_mesh.name = f'{source_mesh.name}_clipped'
clipped_mesh.remove_unused_vertices()
return clipped_mesh
def _clip_crown(crown_mesh, plane):
"""Performs the clipping operation of the crown_mesh and determines the obtained boundaries.
This is the heart method of the class.
"""
vertices = crown_mesh.vertices
above_vertices_mask = crown_mesh._clipping_data['above_vertices_mask']
below_vertices_mask = crown_mesh._clipping_data['below_vertices_mask']
on_vertices_mask = crown_mesh._clipping_data['on_vertices_mask']
# TODO: Vertices pre-projection to be done here
vertices_distances = crown_mesh._clipping_data['vertices_distances']
# Init
clipped_crown_mesh_faces = list()
clipped_crown_mesh_relative_faces_ids = list()
direct_boundary_edges = dict()
inv_boundary_edges = dict()
intersections_vertices = list()
index_new_vertices = crown_mesh.nb_vertices
for face_id in range(crown_mesh.nb_faces):
face = crown_mesh.get_face(face_id)
# # Determining the type of face clipping
v_above_face = np.where(above_vertices_mask[face])[0]
v_on_face = np.where(on_vertices_mask[face])[0]
v_below_face = np.where(below_vertices_mask[face])[0]
nb_above = len(v_above_face)
nb_on = len(v_on_face)
nb_below = len(v_below_face)
face_type = str(nb_above) + str(nb_on) + str(nb_below)
if face_type == '202':
# 0*-----*3
# | |
# ----o-----o----
# | |
# 1*-----*2
if v_above_face[1] == v_above_face[0] + 1:
face = np.roll(face, -v_above_face[1])
p0, p1, p2, p3 = vertices[face]
ileft = plane.get_edge_intersection(p0, p1)
iright = plane.get_edge_intersection(p2, p3)
intersections_vertices += [ileft, iright]
boundary_edge = [index_new_vertices, index_new_vertices + 1]
clipped_crown_mesh_faces.append(
[index_new_vertices, face[1], face[2], index_new_vertices + 1])
clipped_crown_mesh_relative_faces_ids.append(face_id)
index_new_vertices += 2
elif face_type == '301':
# *2
# / \
# / \
# / \
# 3* *1
# \ /
# ---o---o---
# \ /
# *0
face = np.roll(face, -v_below_face[0])
p0, p1, p3 = vertices[face[[0, 1, 3]]]
ileft = plane.get_edge_intersection(p0, p3)
iright = plane.get_edge_intersection(p0, p1)
intersections_vertices += [ileft, iright]
boundary_edge = [index_new_vertices, index_new_vertices + 1]
clipped_crown_mesh_faces.append([
index_new_vertices, face[0], index_new_vertices + 1,
index_new_vertices
])
clipped_crown_mesh_relative_faces_ids.append(face_id)
index_new_vertices += 2
elif face_type == '103':
# *0
# / \
# ---o---o---
# / \
# 1* - - - *3
# \ /
# \ /
# \ /
# *2
face = np.roll(face, -v_above_face[0])
p0, p1, p3 = vertices[face[[0, 1, 3]]]
ileft = plane.get_edge_intersection(p0, p1)
iright = plane.get_edge_intersection(p0, p3)
intersections_vertices += [ileft, iright]
boundary_edge = [index_new_vertices, index_new_vertices + 1]
clipped_crown_mesh_faces.append(
[index_new_vertices, face[1], face[3], index_new_vertices + 1])
clipped_crown_mesh_relative_faces_ids.append(face_id)
clipped_crown_mesh_faces.append(
[face[1], face[2], face[3], face[1]])
clipped_crown_mesh_relative_faces_ids.append(face_id)
index_new_vertices += 2
elif face_type == '102':
# *O
# / \
# ---o---o---
# / \
# 1*-------*2
face = np.roll(face, -v_above_face[0])
p0, p1, p2 = vertices[face]
ileft = plane.get_edge_intersection(p0, p1)
iright = plane.get_edge_intersection(p0, p2)
intersections_vertices += [ileft, iright]
boundary_edge = [index_new_vertices, index_new_vertices + 1]
clipped_crown_mesh_faces.append(
[index_new_vertices, face[1], face[2], index_new_vertices + 1])
clipped_crown_mesh_relative_faces_ids.append(face_id)
index_new_vertices += 2
elif face_type == '201': # done
# 2*-------*1
# \ /
# ---o---o---
# \ /
# *0
face = np.roll(face, -v_below_face[0])
p0, p1, p2 = vertices[face]
ileft = plane.get_edge_intersection(p0, p2)
iright = plane.get_edge_intersection(p0, p1)
intersections_vertices += [ileft, iright]
boundary_edge = [index_new_vertices, index_new_vertices + 1]
clipped_crown_mesh_faces.append([
index_new_vertices, face[0], index_new_vertices + 1,
index_new_vertices
])
clipped_crown_mesh_relative_faces_ids.append(face_id)
index_new_vertices += 2
elif face_type == '211':
# *3 *1
# / \ / \
# / *2 or 2* \
# 0/ / \ \0
# ---*---o--- ---o---*---
# \ / \ /
# *1 *3
#
face = np.roll(face, -v_on_face[0])
if vertices_distances[face[1]] < 0.:
p1, p2 = vertices[face[[1, 2]]]
iright = plane.get_edge_intersection(p1, p2)
intersections_vertices.append(iright)
boundary_edge = [face[0], index_new_vertices]
clipped_crown_mesh_faces.append(
[face[0], face[1], index_new_vertices, face[0]])
else:
p2, p3 = vertices[face[[2, 3]]]
ileft = plane.get_edge_intersection(p2, p3)
intersections_vertices.append(ileft)
boundary_edge = [index_new_vertices, face[0]]
clipped_crown_mesh_faces.append(
[index_new_vertices, face[3], face[0], index_new_vertices])
clipped_crown_mesh_relative_faces_ids.append(face_id)
index_new_vertices += 1
elif face_type == '112':
# *3 *1
# / \ / \
# ---*---o--- or ---o---*---
# 0\ \ / /0
# \ *2 2* /
# \ / \ /
# *1 *3
face = np.roll(face, -v_on_face[0])
if vertices_distances[face[1]] < 0.:
p2, p3 = vertices[face[[2, 3]]]
iright = plane.get_edge_intersection(p2, p3)
intersections_vertices.append(iright)
boundary_edge = [face[0], index_new_vertices]
clipped_crown_mesh_faces.append(
[face[0], face[1], face[2], index_new_vertices])
else:
p1, p2 = vertices[face[[1, 2]]]
ileft = plane.get_edge_intersection(p1, p2)
intersections_vertices.append(ileft)
boundary_edge = [index_new_vertices, face[0]]
clipped_crown_mesh_faces.append(
[index_new_vertices, face[2], face[3], face[0]])
clipped_crown_mesh_relative_faces_ids.append(face_id)
index_new_vertices += 1
elif face_type == '013':
# -----*-----
# / \
# / \
# * *
# \ /
# \ /
# *
boundary_edge = None
clipped_crown_mesh_faces.append(list(face))
clipped_crown_mesh_relative_faces_ids.append(face_id)
elif face_type == '210' or face_type == '310':
# *-------* *
# \ 210 / / \ 310
# \ / * *
# \ / \ /
# ----*---- ----*----
boundary_edge = None
elif face_type == '111':
# *2 *1
# /| |\
# / | | \
# ---*--o--- or ---o--*---
# 0\ | | /0
# \| |/
# *1 *2
face = np.roll(face, -v_on_face[0])
p1, p2 = vertices[face[[1, 2]]]
if vertices_distances[face[1]] < 0.:
iright = plane.get_edge_intersection(p1, p2)
intersections_vertices.append(iright)
boundary_edge = [face[0], index_new_vertices]
clipped_crown_mesh_faces.append(
[face[0], face[1], index_new_vertices, face[0]])
else:
ileft = plane.get_edge_intersection(p1, p2)
intersections_vertices.append(ileft)
boundary_edge = [index_new_vertices, face[0]]
clipped_crown_mesh_faces.append(
[index_new_vertices, face[2], face[0], index_new_vertices])
clipped_crown_mesh_relative_faces_ids.append(face_id)
index_new_vertices += 1
elif face_type == '120':
# *O
# / \
# / \
# 1/ \2
# ----*-------*----
# face = np.roll(face, -v_above_face[0])
# boundary_edge = [face[1], face[2]]
# FIXME: quick fix here : robust ?
boundary_edge = None
elif face_type == '021':
# ----*-------*----
# 2\ /1
# \ /
# \ /
# *0
face = np.roll(face, -v_below_face[0])
boundary_edge = [face[2], face[1]]
face = list(face)
face.append(face[0])
clipped_crown_mesh_faces.append(face)
clipped_crown_mesh_relative_faces_ids.append(face_id)
elif face_type == '022':
# ----*-----*----
# 0| |3
# | |
# 1*-----*2
if v_on_face[1] == v_on_face[0] + 1:
face = np.roll(face, -v_on_face[1])
boundary_edge = [face[0], face[3]]
clipped_crown_mesh_faces.append(list(face))
clipped_crown_mesh_relative_faces_ids.append(face_id)
elif face_type == '012':
# ------*------
# / \
# / \
# / \
# *-------*
boundary_edge = None
face = list(face)
face.append(face[0])
clipped_crown_mesh_faces.append(face)
clipped_crown_mesh_relative_faces_ids.append(face_id)
elif face_type == '220':
# 0*-----*3
# | |
# 1| |2
# ----*-----*----
# if v_above_face[1] == v_above_face[0] + 1:
# face = np.roll(face, -v_above_face[1])
# boundary_edge = [face[1], face[2]]
# FIXME: quick fix here : robust ?
boundary_edge = None
elif face_type == '121':
# *0
# / \
# / \
# ---*-----*---
# 1\ /3
# \ /
# *2
face = np.roll(face, -v_above_face[0])
boundary_edge = [face[1], face[3]]
clipped_crown_mesh_faces.append(
[face[1], face[2], face[3], face[1]])
clipped_crown_mesh_relative_faces_ids.append(face_id)
elif face_type == '300' or face_type == '400':
# * *-----*
# / \ | |
# /300\ or | 400 |
# *-----* *-----*
# ____________ ______________
boundary_edge = None
elif face_type == '003':
# -----------
# *
# / \
# / \
# *-----*
boundary_edge = None
face = list(face)
face.append(face[0])
clipped_crown_mesh_faces.append(face)
clipped_crown_mesh_relative_faces_ids.append(face_id)
elif face_type == '004':
# ---------------
# *-----*
# | |
# | |
# *-----*
boundary_edge = None
clipped_crown_mesh_faces.append(list(face))
clipped_crown_mesh_relative_faces_ids.append(face_id)
elif face_type == '030' or face_type == '040':
# Face is totally on the plane --> rare case...
boundary_edge = None
else:
raise Exception("Face %u clipping case %s not known." %
(face_id, face_type))
# Building boundary connectivity
if boundary_edge is not None:
direct_boundary_edges[boundary_edge[0]] = boundary_edge[1]
inv_boundary_edges[boundary_edge[1]] = boundary_edge[0]
if len(intersections_vertices) > 0:
vertices = np.concatenate((vertices, intersections_vertices))
clipped_crown_mesh = Mesh(vertices, clipped_crown_mesh_faces)
clipped_crown_mesh._clipping_data = {
'faces_ids':
crown_mesh._clipping_data['faces_ids']
[clipped_crown_mesh_relative_faces_ids]
}
return clipped_crown_mesh
