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# ***************************************************************************
# * Copyright (c) 2009, 2010 Yorik van Havre <yorik@uncreated.net> *
# * Copyright (c) 2009, 2010 Ken Cline <cline@frii.com> *
# * *
# * This file is part of the FreeCAD CAx development system. *
# * *
# * This program is free software; you can redistribute it and/or modify *
# * it under the terms of the GNU Lesser General Public License (LGPL) *
# * as published by the Free Software Foundation; either version 2 of *
# * the License, or (at your option) any later version. *
# * for detail see the LICENCE text file. *
# * *
# * FreeCAD 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 Library General Public License for more details. *
# * *
# * You should have received a copy of the GNU Library General Public *
# * License along with FreeCAD; if not, write to the Free Software *
# * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 *
# * USA *
# * *
# ***************************************************************************
"""Provides various functions to work with faces."""
## @package faces
# \ingroup draftgeoutils
# \brief Provides various functions to work with faces.
import lazy_loader.lazy_loader as lz
import DraftVecUtils
from FreeCAD import Base
from draftgeoutils.geometry import are_coplanar
# Delay import of module until first use because it is heavy
Part = lz.LazyLoader("Part", globals(), "Part")
## \addtogroup draftgeoutils
# @{
def concatenate(shape):
"""Turn several faces into one."""
boundary_edges = getBoundary(shape)
sorted_edges = Part.sortEdges(boundary_edges)
try:
wires = [Part.Wire(edges) for edges in sorted_edges]
face = Part.makeFace(wires, "Part::FaceMakerBullseye")
except Base.FreeCADError:
print(
"DraftGeomUtils: Fails to join faces into one. "
+ "The precision of the faces would be insufficient"
)
return shape
else:
if not wires[0].isClosed():
return wires[0]
else:
return face
def getBoundary(shape):
"""Return the boundary edges of a group of faces."""
if isinstance(shape, list):
shape = Part.makeCompound(shape)
# Make a lookup-table where we get the number of occurrences
# to each edge in the fused face
table = dict()
for f in shape.Faces:
for e in f.Edges:
hash_code = e.hashCode()
if hash_code in table:
table[hash_code] = table[hash_code] + 1
else:
table[hash_code] = 1
# Filter out the edges shared by more than one sub-face
bound = list()
for e in shape.Edges:
if table[e.hashCode()] == 1:
bound.append(e)
return bound
def is_coplanar(faces, tol=-1):
"""Return True if all faces in the given list are coplanar.
Parameters
----------
faces: list
List of faces to check coplanarity.
tol: float, optional
It defaults to `-1`, the tolerance of confusion, equal to 1e-7.
Is the maximum deviation to be considered coplanar.
Returns
-------
out: bool
True if all face are coplanar. False in other case.
"""
first_face = faces[0]
for face in faces:
if not are_coplanar(first_face, face, tol):
return False
return True
isCoplanar = is_coplanar
def bind(w1, w2, per_segment=False):
"""Bind 2 wires by their endpoints and returns a face / compound of faces.
If per_segment is True and the wires have the same number of edges, the
wires are processed per segment: a separate face is created for each pair
of edges (one from w1 and one from w2), and the faces are then fused. This
avoids problems with walls based on wires that selfintersect, or that have
a loop that ends in a T-connection (f.e. a wire shaped like a number 6).
"""
def create_face(w1, w2):
try:
w3 = Part.LineSegment(w1.Vertexes[0].Point, w2.Vertexes[0].Point).toShape()
w4 = Part.LineSegment(w1.Vertexes[-1].Point, w2.Vertexes[-1].Point).toShape()
except Part.OCCError:
print("DraftGeomUtils: unable to bind wires")
return None
if w3.section(w4).Vertexes:
print("DraftGeomUtils: Problem, a segment is self-intersecting, please check!")
f = Part.Face(Part.Wire(w1.Edges + [w3] + w2.Edges + [w4]))
return f
if not w1 or not w2:
print("DraftGeomUtils: unable to bind wires")
return None
if per_segment and len(w1.Edges) > 1 and len(w1.Edges) == len(w2.Edges):
faces = []
faces_list = []
for edge1, edge2 in zip(w1.Edges, w2.Edges):
# Find touching edges due to ArchWall Align in opposite
# directions, and/or opposite edge orientations.
#
# w1 o-----o w1 o-----o w1 o-----o
# | w1 | |
# w2 +-----x-----o w1 w2 +-----+ w2 +-----+
# w2 | w2 | w1 w2 | w1
# +-----+ w2 o-----o w1 +-----+ w2
# | |
# +-----+ w2 o-----o w1
#
# TODO Maybe those edge pair should not be generated in offsetWire()
# and separate wires should then be returned.
# If edges touch the Shape.section() compound will have 1 or 2 vertexes:
if edge1.section(edge2).Vertexes:
faces_list.append(faces) # Break into separate list
faces = [] # Reset original faces variable
continue # Skip the touching edge pair
else:
face = create_face(edge1, edge2)
if face is None:
return None
faces.append(face)
# Usually there is last series of face after above 'for' routine,
# EXCEPT when the last edge pair touch, faces had been appended
# to faces_list, and reset faces =[]
#
# TODO Need fix further anything if there is a empty [] in faces_list ?
#
if faces_list and faces:
# if wires are closed, 1st & last series of faces might be connected
# except when
# 1) there are only 2 series, connecting would return invalid shape
# 2) 1st series of faces happens to be [], i.e. 1st edge pairs touch
#
if w1.isClosed() and w2.isClosed() and len(faces_list) > 1 and faces_list[0]:
faces_list[0].extend(
faces
) # TODO: To be reviewed, 'afterthought' on 2025.3.29, seems by 'extend', faces in 1st and last faces are not in sequential order
else:
faces_list.append(faces) # Break into separate list
from collections import Counter
if faces_list:
faces_fused_list = []
for faces in faces_list:
dir = []
countDir = None
for f in faces:
dir.append(f.normalAt(0, 0).z)
countDir = Counter(dir)
l = len(faces)
m = max(countDir.values()) # max(countDir, key=countDir.get)
if m != l:
print(
"DraftGeomUtils: Problem, the direction of "
+ str(l - m)
+ " out of "
+ str(l)
+ " segment is reversed, please check!"
)
if len(faces) > 1:
# Below not good if a face is self-intersecting or reversed
# faces_fused = faces[0].fuse(faces[1:]).removeSplitter().Faces[0]
rf = faces[0]
for f in faces[1:]:
rf = rf.fuse(f).removeSplitter().Faces[0]
# rf = rf.fuse(f) # Not working
# rf = rf.removeSplitter().Faces[0] # Not working
faces_fused_list.append(rf)
# faces might be empty list [], see above; skip if empty
elif faces:
faces_fused_list.append(faces[0]) # Only 1 face
return Part.Compound(faces_fused_list)
else:
dir = []
countDir = None
for f in faces:
dir.append(f.normalAt(0, 0).z)
countDir = Counter(dir)
l = len(faces)
m = max(countDir.values()) # max(countDir, key=countDir.get)
if m != l:
print(
"DraftGeomUtils: Problem, the direction of "
+ str(l - m)
+ " out of "
+ str(l)
+ " segment is reversed, please check!"
)
# Below not good if a face is self-intersecting or reversed
# return faces[0].fuse(faces[1:]).removeSplitter().Faces[0]
rf = faces[0]
for f in faces[1:]:
rf = rf.fuse(f).removeSplitter().Faces[0]
# rf = rf.fuse(f) # Not working
# rf = rf.removeSplitter().Faces[0] # Not working
return rf
elif w1.isClosed() and w2.isClosed():
d1 = w1.BoundBox.DiagonalLength
d2 = w2.BoundBox.DiagonalLength
if d1 < d2:
w1, w2 = w2, w1
# return Part.Face(w1).cut(Part.Face(w2)).Faces[0] # Only works if wires do not self-intersect.
try:
face = Part.Face([w1, w2])
face.fix(1e-7, 0, 1)
return face
except Part.OCCError:
print("DraftGeomUtils: unable to bind wires")
return None
else:
return create_face(w1, w2)
def cleanFaces(shape):
"""Remove inner edges from coplanar faces."""
faceset = shape.Faces
def find(hc):
"""Find a face with the given hashcode."""
for f in faceset:
if f.hashCode() == hc:
return f
def findNeighbour(hface, hfacelist):
"""Find the first neighbour of a face, and return its index."""
eset = []
for e in find(hface).Edges:
eset.append(e.hashCode())
for i in range(len(hfacelist)):
for ee in find(hfacelist[i]).Edges:
if ee.hashCode() in eset:
return i
return None
# build lookup table
lut = {}
for face in faceset:
for edge in face.Edges:
if edge.hashCode() in lut:
lut[edge.hashCode()].append(face.hashCode())
else:
lut[edge.hashCode()] = [face.hashCode()]
# print("lut:",lut)
# take edges shared by 2 faces
sharedhedges = []
for k, v in lut.items():
if len(v) == 2:
sharedhedges.append(k)
# print(len(sharedhedges)," shared edges:",sharedhedges)
# find those with same normals
targethedges = []
for hedge in sharedhedges:
faces = lut[hedge]
n1 = find(faces[0]).normalAt(0.5, 0.5)
n2 = find(faces[1]).normalAt(0.5, 0.5)
if n1 == n2:
targethedges.append(hedge)
# print(len(targethedges)," target edges:",targethedges)
# get target faces
hfaces = []
for hedge in targethedges:
for f in lut[hedge]:
if f not in hfaces:
hfaces.append(f)
# print(len(hfaces)," target faces:",hfaces)
# sort islands
islands = [[hfaces.pop(0)]]
currentisle = 0
currentface = 0
found = True
while hfaces:
if not found:
if len(islands[currentisle]) > (currentface + 1):
currentface += 1
found = True
else:
islands.append([hfaces.pop(0)])
currentisle += 1
currentface = 0
found = True
else:
f = findNeighbour(islands[currentisle][currentface], hfaces)
if f is not None:
islands[currentisle].append(hfaces.pop(f))
else:
found = False
# print(len(islands)," islands:",islands)
# make new faces from islands
newfaces = []
treated = []
for isle in islands:
treated.extend(isle)
fset = []
for i in isle:
fset.append(find(i))
bounds = getBoundary(fset)
shp = Part.Wire(Part.__sortEdges__(bounds))
shp = Part.Face(shp)
if shp.normalAt(0.5, 0.5) != find(isle[0]).normalAt(0.5, 0.5):
shp.reverse()
newfaces.append(shp)
# print("new faces:",newfaces)
# add remaining faces
for f in faceset:
if not f.hashCode() in treated:
newfaces.append(f)
# print("final faces")
# finishing
fshape = Part.makeShell(newfaces)
if shape.isClosed():
fshape = Part.makeSolid(fshape)
return fshape
def removeSplitter(shape):
"""Return a face from removing the splitter in a list of faces.
This is an alternative, shared edge-based version of Part.removeSplitter.
Returns a face, or `None` if the operation failed.
"""
lookup = dict()
for f in shape.Faces:
for e in f.Edges:
h = e.hashCode()
if h in lookup:
lookup[h].append(e)
else:
lookup[h] = [e]
edges = [e[0] for e in lookup.values() if len(e) == 1]
try:
face = Part.Face(Part.Wire(edges))
except Part.OCCError:
# operation failed
return None
else:
if face.isValid():
return face
return None
## @}
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