def curves2d_from_offset(event=None):
r"""
@param display:
"""
pnt2d_array = TColgp_Array1OfPnt2d(1, 5)
pnt2d_array.SetValue(1, gp_Pnt2d(-4, 0))
pnt2d_array.SetValue(2, gp_Pnt2d(-7, 2))
pnt2d_array.SetValue(3, gp_Pnt2d(-6, 3))
pnt2d_array.SetValue(4, gp_Pnt2d(-4, 3))
pnt2d_array.SetValue(5, gp_Pnt2d(-3, 5))
spline_1 = Geom2dAPI_PointsToBSpline(pnt2d_array).Curve()
dist = 1
offset_curve1 = Geom2d_OffsetCurve(spline_1, dist)
result = offset_curve1.IsCN(2)
print("Offset curve yellow is C2: %r" % result)
dist2 = 1.5
offset_curve2 = Geom2d_OffsetCurve(spline_1, dist2)
result2 = offset_curve2.IsCN(2)
print("Offset curve blue is C2: %r" % result2)
display.DisplayShape(spline_1)
display.DisplayShape(offset_curve1, color='YELLOW')
display.DisplayShape(offset_curve2, color='BLUE', update=True)
def make_shape(self):
# 1 - retrieve the data from the UIUC airfoil data page
foil_dat_url = 'http://www.ae.illinois.edu/m-selig/ads/coord_seligFmt/%s.dat' % self.profile
if py2:
f = urllib2.urlopen(foil_dat_url)
else:
http = urllib3.PoolManager()
f = http.urlopen('GET', foil_dat_url).data.decode()
f = io.StringIO(f)
plan = gp_Pln(gp_Pnt(0., 0., 0.), gp_Dir(0., 0.,
1.)) # Z=0 plan / XY plan
section_pts_2d = []
for line in f.readlines()[1:]: # The first line contains info only
# 2 - do some cleanup on the data (mostly dealing with spaces)
line = line.lstrip().rstrip().replace(' ', ' ').replace(
' ', ' ').replace(' ', ' ')
data = line.split(' ') # data[0] = x coord. data[1] = y coord.
# 3 - create an array of points
if len(data) == 2: # two coordinates for each point
section_pts_2d.append(
gp_Pnt2d(
float(data[0]) * self.chord,
float(data[1]) * self.chord))
# 4 - use the array to create a spline describing the airfoil section
spline_2d = Geom2dAPI_PointsToBSpline(
point2d_list_to_TColgp_Array1OfPnt2d(section_pts_2d),
len(section_pts_2d) - 1, # order min
len(section_pts_2d)) # order max
spline = geomapi.To3d(spline_2d.Curve(), plan)
# 5 - figure out if the trailing edge has a thickness or not,
# and create a Face
try:
# first and last point of spline -> trailing edge
trailing_edge = make_edge(
gp_Pnt(section_pts_2d[0].X(), section_pts_2d[0].Y(), 0.0),
gp_Pnt(section_pts_2d[-1].X(), section_pts_2d[-1].Y(), 0.0))
face = BRepBuilderAPI_MakeFace(
make_wire([make_edge(spline), trailing_edge]))
except AssertionError:
# the trailing edge segment could not be created, probably because
# the points are too close
# No need to build a trailing edge
face = BRepBuilderAPI_MakeFace(make_wire(make_edge(spline)))
# 6 - extrude the Face to create a Solid
return BRepPrimAPI_MakePrism(
face.Face(), gp_Vec(gp_Pnt(0., 0., 0.),
gp_Pnt(0., 0., self.span))).Shape()
def bspline():
# the first bspline
array = TColgp_Array1OfPnt2d(1, 5)
array.SetValue(1, gp_Pnt2d(0, 0))
array.SetValue(2, gp_Pnt2d(1, 2))
array.SetValue(3, gp_Pnt2d(2, 3))
array.SetValue(4, gp_Pnt2d(4, 3))
array.SetValue(5, gp_Pnt2d(5, 5))
bspline_1 = Geom2dAPI_PointsToBSpline(array).Curve()
# the second one
harray = TColgp_HArray1OfPnt2d(1, 5)
harray.SetValue(1, gp_Pnt2d(0, 0))
harray.SetValue(2, gp_Pnt2d(1, 2))
harray.SetValue(3, gp_Pnt2d(2, 3))
harray.SetValue(4, gp_Pnt2d(4, 3))
harray.SetValue(5, gp_Pnt2d(5, 5))
anInterpolation = Geom2dAPI_Interpolate(harray.GetHandle(), False, 0.01)
anInterpolation.Perform()
bspline_2 = anInterpolation.Curve()
harray2 = TColgp_HArray1OfPnt2d(1, 5)
harray2.SetValue(1, gp_Pnt2d(11, 0))
harray2.SetValue(2, gp_Pnt2d(12, 2))
harray2.SetValue(3, gp_Pnt2d(13, 3))
harray2.SetValue(4, gp_Pnt2d(15, 3))
harray2.SetValue(5, gp_Pnt2d(16, 5))
anInterpolation2 = Geom2dAPI_Interpolate(harray2.GetHandle(), True, 0.01)
anInterpolation2.Perform()
bspline_3 = anInterpolation2.Curve()
for j in range(array.Lower(), array.Upper() + 1):
p = array.Value(j)
display.DisplayShape(p, update=False)
for j in range(harray.Lower(), harray.Upper() + 1):
p = harray.Value(j)
display.DisplayShape(p, update=False)
for j in range(harray2.Lower(), harray2.Upper() + 1):
p = harray2.Value(j)
display.DisplayShape(p, update=False)
display.DisplayShape(bspline_1, update=False)
display.DisplayShape(bspline_2, update=False, color='GREEN')
display.DisplayShape(bspline_3, update=True, color='BLUE')