def make_offset(wire_or_face, offsetDistance, altitude=0, joinType=GeomAbs_Arc):
'''
builds a offsetted wire or face from a wire or face
construct an offsetted version of the shape
@param wire_or_face: the wire or face to offset
@param offsetDistance: the distance to offset
@param altitude: move the offsetted shape to altitude
from the normal of the wire or face
@param joinType: the type of offset you want
can be one of GeomAbs_Arc, GeomAbs_Tangent, GeomAbs_Intersection
note: a shape that has a negative offsetDistance will return
a sharp corner
'''
from OCCT.BRepOffsetAPI import BRepOffsetAPI_MakeOffset
_joints = [GeomAbs_Arc, GeomAbs_Tangent, GeomAbs_Intersection]
assert joinType in _joints, '%s is not one of %s' % (joinType, _joints)
try:
offset = BRepOffsetAPI_MakeOffset(wire_or_face, joinType)
offset.Perform(offsetDistance, altitude)
if offset.IsDone():
return ST(offset.Shape())
else:
return None
except RuntimeError('failed to offset shape'):
return None
def __init__(self,
spine,
distance,
altitude=0.,
join=Geometry.ARC,
is_open=False):
offset = BRepOffsetAPI_MakeOffset(spine.object, join, is_open)
offset.Perform(distance, altitude)
self._w = Wire(offset.Shape())
def update_shape(self, change=None):
d = self.declaration
shape = Topology.cast_shape(self.get_shape_to_offset())
if isinstance(shape, TopoDS_Edge):
shape = BRepBuilderAPI_MakeWire(shape).Wire()
elif not isinstance(shape, (TopoDS_Wire, TopoDS_Face)):
t = type(shape)
raise TypeError(
"Unsupported child shape %s when using planar mode" % t)
offset_shape = BRepOffsetAPI_MakeOffset(
shape, self.join_types[d.join_type], not d.closed)
offset_shape.Perform(d.offset)
if not offset_shape.IsDone():
# Note: Lines cannot be offset as they have no plane of reference
raise ValueError("Could not perform offset: %s" % d)
self.shape = offset_shape.Shape()
def create_offsets(face, nr_of_counters, distance_between_contours):
offset = BRepOffsetAPI_MakeOffset()
offset.Init(GeomAbs_Arc)
for wi in TopologyExplorer(face).wires():
offset.AddWire(wi)
for i in range(nr_of_counters):
offset.Perform(-distance_between_contours * i)
if offset.IsDone():
yield offset.Shape()