277 lines
8.8 KiB
Python
277 lines
8.8 KiB
Python
# ***************************************************************************
|
|
# * 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.general import precision
|
|
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):
|
|
"""Bind 2 wires by their endpoints and returns a face."""
|
|
if not w1 or not w2:
|
|
print("DraftGeomUtils: unable to bind wires")
|
|
return None
|
|
|
|
if w1.isClosed() and w2.isClosed():
|
|
d1 = w1.BoundBox.DiagonalLength
|
|
d2 = w2.BoundBox.DiagonalLength
|
|
if d1 > d2:
|
|
# w2.reverse()
|
|
return Part.Face([w1, w2])
|
|
else:
|
|
# w1.reverse()
|
|
return Part.Face([w2, w1])
|
|
else:
|
|
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()
|
|
return Part.Face(Part.Wire(w1.Edges+[w3] + w2.Edges+[w4]))
|
|
except Part.OCCError:
|
|
print("DraftGeomUtils: unable to bind wires")
|
|
return None
|
|
|
|
|
|
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
|
|
|
|
## @}
|