def interpolate_points_to_spline(list_of_points,
start_tangent,
end_tangent,
filter_pts=True,
tolerance=TOLERANCE):
'''
GeomAPI_Interpolate is buggy: need to use `fix` in order
to get the right points in...
'''
def fix(li, _type):
'''function factory for 1-dimensional TCol* types'''
pts = _type(1, len(li))
for n, i in enumerate(li):
pts.SetValue(n + 1, i)
pts.thisown = False
return pts
if filter_pts:
list_of_points = filter_points_by_distance(list_of_points, 0.1)
fixed_points = fix(list_of_points, TColgp_HArray1OfPnt)
try:
interp = GeomAPI_Interpolate(fixed_points.GetHandle(), False,
tolerance)
interp.Load(start_tangent, end_tangent, False)
interp.Perform()
if interp.IsDone():
return interp.Curve()
except RuntimeError:
print("Failed to interpolate the shown points")
def interpolate_points_vectors_to_spline(list_of_points,
list_of_vectors,
vector_mask=None,
tolerance=TOLERANCE):
'''
build a curve from a set of points and vectors
the vectors describe the tangent vector at the corresponding point
'''
# GeomAPI_Interpolate is buggy: need to use `fix` in order to
# get the right points in...
assert len(list_of_points) == len(
list_of_vectors), 'vector and point list not of same length'
def fix(li, _type):
'''function factory for 1-dimensional TCol* types'''
pts = _type(1, len(li))
for n, i in enumerate(li):
pts.SetValue(n + 1, i)
pts.thisown = False
return pts
if vector_mask is not None:
assert len(vector_mask) == len(
list_of_points
), 'length vector mask is not of length points list nor []'
else:
vector_mask = [True for i in range(len(list_of_points))]
fixed_mask = fix(vector_mask, TColStd_HArray1OfBoolean)
fixed_points = fix(list_of_points, TColgp_HArray1OfPnt)
fixed_vectors = fix(list_of_vectors, TColgp_Array1OfVec)
try:
interp = GeomAPI_Interpolate(fixed_points.GetHandle(), False,
tolerance)
interp.Load(fixed_vectors, fixed_mask.GetHandle(), False)
interp.Perform()
if interp.IsDone():
return interp.Curve()
except RuntimeError:
# the exception was unclear
raise RuntimeError('FAILED TO INTERPOLATE THE POINTS')
def points_to_bspline(pnts, deg=3, periodic=False, tangents=None,
scale=False, continuity=GeomAbs_C2):
"""
Points to bspline: originally from pythonocc-utils, changed to allow numpy
arrays as input
Paramters
---------
pnts : list or numpy array
array of x, y, z points
deg : integer
degree of the fitted bspline
periodic : Bool (default=False)
If true, OCC.GeomAPI_Interpolate will be used instead of the
GeomAPI_PointsToBspline. Curve tangent vectors can then be
enforced at the interpolation pnts
tangents : array (default=None)
list of [x,y,z] tangent vectors to be specificied at points:
if only 2 tangents are specified, these will be enforced at the
start and end points, otherwise tangents should have the same length
as pnts and will be enforced at each point.
Scale : Bool (default=False)
Will scale the tangents (gives a smoother Periodic curve if False)
continuity : OCC.GeomAbs.GeomAbs_XX type (default C2)
The order of continuity (C^0, C^1, C^2, G^0, ....)
Returns
-------
crv : OCC.Geom.BSplineCurve
Notes
-----
"""
if not periodic and (tangents is None):
_type = TColgp_Array1OfPnt
pnts = point_array_to_TColgp_PntArrayType(pnts, _type)
# Fit the curve to the point array
deg_min = deg
deg_max = deg
crv = GeomAPI_PointsToBSpline(pnts, deg_min, deg_max, continuity).Curve()
else:
_type = TColgp_HArray1OfPnt
pnts = point_array_to_TColgp_PntArrayType(pnts, _type)
tol = 0.001
interp = GeomAPI_Interpolate(pnts.GetHandle(), periodic, tol)
if tangents is not None:
N = tangents.shape[0]
if N == 2:
try:
interp.Load(gp_Vec(*tangents[0, :]), gp_Vec(*tangents[1, :]),
scale)
except:
# Python 3 issue: using * on numpy array breaks gp_Vec
interp.Load(gp_Vec(*tangents[0, :].tolist()),
gp_Vec(*tangents[1, :].tolist()),
scale)
else:
tan_array = TColgp_Array1OfVec(1, N)
for i in range(1, N + 1):
try:
tan_array.SetValue(i, gp_Vec(*tangents[i - 1, :]))
except TypeError:
# Python 3 issue: using * on numpy array breaks gp_Vec
tan_array.SetValue(i, gp_Vec(*tangents[i - 1, :].tolist()))
tan_flags = TColStd_HArray1OfBoolean(1, N)
tan_flags.Init(True) # Set all true i.e. enforce all tangents
interp.Load(tan_array, tan_flags.GetHandle(), scale)
interp.Perform()
crv = interp.Curve()
return crv