def CutSect(Shape, SpanStation):
"""
Parameters
----------
Shape : TopoDS_Shape
The Shape to find planar cut section (parallel to xz plane)
SpanStation : scalar in range (0, 1)
y-direction location at which to cut Shape
Returns
-------
Section : result of OCC.BRepAlgoAPI.BRepAlgoAPI_Section (TopoDS_Shape)
The cut section of shape given a cut plane parallel to xz at input
Spanstation.
Chord : result of OCC.GC.GC_MakeSegment.Value (Geom_TrimmedCurve)
The Chord line between x direction extremeties
"""
(Xmin, Ymin, Zmin, Xmax, Ymax, Zmax) = ObjectsExtents([Shape])
YStation = Ymin + (Ymax - Ymin) * SpanStation
OriginX = Xmin - 1
OriginZ = Zmin - 1
P = gp_Pln(gp_Pnt(OriginX, YStation, OriginZ), gp_Dir(gp_Vec(0, 1, 0)))
# Note: using 2*extents here as previous +1 trimmed plane too short
CutPlaneSrf = make_face(P, 0, Zmax + 2, 0, Xmax + 2)
I = BRepAlgoAPI_Section(Shape, CutPlaneSrf)
I.ComputePCurveOn1(True)
I.Approximation(True)
I.Build()
Section = I.Shape()
(Xmin, Ymin, Zmin, Xmax, Ymax, Zmax) = ObjectsExtents([Section])
# Currently assume only one edge exists in the intersection:
exp = TopExp_Explorer(Section, TopAbs_EDGE)
edge = topods_Edge(exp.Current())
# Find the apparent chord of the section (that is, the line connecting the
# fore most and aftmost points on the curve
DivPoints = Uniform_Points_on_Curve(edge, 200)
Xs = np.array([pt.X() for pt in DivPoints])
min_idx = np.argmin(Xs)
LeadingPoint = gp_Pnt(Xs[min_idx], DivPoints[min_idx].Y(),
DivPoints[min_idx].Z())
max_idx = np.argmax(Xs)
TrailingPoint = gp_Pnt(Xs[max_idx], DivPoints[max_idx].Y(),
DivPoints[max_idx].Z())
HChord = GC_MakeSegment(TrailingPoint, LeadingPoint).Value()
# Chord = HChord.GetObject()
return Section, HChord
def __call__(self, plane: gp.gp_Pln, vertex=None, edge_dict=None, **kwargs):
splt = BRepFeat_SplitShape()
if isinstance(self._base, TopoDS_Shape):
base_shape = self._base
else:
base_shape = self._base.Shape()
splt.Init(base_shape)
sect = BRepAlgoAPI_Section(base_shape, plane, False)
sect.ComputePCurveOn1(True)
sect.Approximation(True)
sect.Build()
self.cutting_edge = sect.Shape()
ancestors = set()
new_faces = []
edge_iter = TopExp_Explorer(self.cutting_edge, TopAbs_EDGE)
while edge_iter.More():
base_iter = TopExp_Explorer(base_shape, TopAbs_FACE)
curr_edge = edge_iter.Current()
while base_iter.More():
curr_face = base_iter.Current()
if sect.HasAncestorFaceOn1(curr_edge, curr_face):
k, v = hash(curr_face), hash(curr_edge)
if (k, v) not in self.ancestors:
ancestors.add((k, v))
e = topods.Edge(curr_edge)
f = topods.Face(curr_face)
splt.Add(e, f)
# todo - only add the closest one !!!!
new_faces.append(f)
self.added.append(e)
break
# if sect.HasAncestorFaceOn2(curr_edge, curr_face):
# print('has2', curr_edge, curr_face)
# pass
base_iter.Next()
edge_iter.Next()
# -------------------------------------
splt.Build()
new_shape = splt.Shape()
sect.Destroy()
return new_shape
def split_shape(event=None):
S = BRepPrimAPI_MakeBox(gp_Pnt(-100, -60, -80), 150, 200, 170).Shape()
asect = BRepAlgoAPI_Section(S, gp_Pln(1, 2, 1, -15), False)
asect.ComputePCurveOn1(True)
asect.Approximation(True)
asect.Build()
R = asect.Shape()
asplit = BRepFeat_SplitShape(S)
for edg in Topo(R).edges():
face = TopoDS_Face()
if asect.HasAncestorFaceOn1(edg, face):
asplit.Add(edg, face)
asplit.Build()
display.EraseAll()
display.DisplayShape(asplit.Shape())
display.FitAll()
def section(event=None):
Torus = BRepPrimAPI_MakeTorus(120, 20).Shape()
radius = 120.0
sections = []
for i in range(-3, 4):
# Create Sphere
Sphere = BRepPrimAPI_MakeSphere(gp_Pnt(26 * 3 * i, 0, 0), radius).Shape()
# Computes Torus/Sphere section
section = BRepAlgoAPI_Section(Torus, Sphere, False)
section.ComputePCurveOn1(True)
section.Approximation(True)
section.Build()
sections.append(section)
display.EraseAll()
display.DisplayShape(Torus)
for section in sections:
display.DisplayShape(section.Shape())
display.FitAll()
def split_solid(base, plane):
splt = BRepFeat_SplitShape()
splt.Init(base)
sect = BRepAlgoAPI_Section(base, plane, False)
sect.ComputePCurveOn1(True)
sect.Approximation(True)
sect.Build()
edge = sect.Shape()
rdict = set()
# print(Topo(edge).number_of_edges())
Ex = TopExp_Explorer(edge, TopAbs_EDGE)
while Ex.More():
# print('edge', Ex.Current())
base_iter = TopExp_Explorer(base, TopAbs_FACE)
curr = Ex.Current()
while base_iter.More():
# print('face', base_iter.Current())
bface = base_iter.Current()
if sect.HasAncestorFaceOn1(curr, bface):
# print('has1', curr, bface)
k, v = hash(bface), hash(curr)
if (k, v) not in rdict:
rdict.add((k, v))
e = topods.Edge(curr)
f = topods.Face(bface)
splt.Add(e, f)
if sect.HasAncestorFaceOn2(curr, bface):
# print('has2', curr, bface)
pass
base_iter.Next()
Ex.Next()
splt.Build()
return splt.Shape()
