def approximate(self,
segments: int = 40,
ucs: 'UCS' = None) -> List['Vertex']:
"""
Approximate B-spline by a polyline with `segments` line segments. If `ucs` is not ``None``, ucs defines an
:class:`~ezdxf.math.UCS`, to transformed the curve into :ref:`OCS`. The control points are placed xy-plane of
the UCS, don't use z-axis coordinates, if so make sure all control points are in a plane parallel to the OCS
base plane (UCS xy-plane), else the result is unpredictable and depends on the CAD application used to open the
DXF file, it maybe crash.
Args:
segments: count of line segments for approximation, vertex count is `segments` + 1
ucs: :class:`~ezdxf.math.UCS` definition, control points in ucs coordinates.
Returns:
list of vertices in :class:`~ezdxf.math.OCS` as :class:`~ezdxf.math.Vec3` objects
"""
if self.closed:
spline = BSplineClosed(self.control_points, order=self.degree + 1)
else:
spline = BSpline(self.control_points, order=self.degree + 1)
vertices = spline.approximate(segments)
if ucs is not None:
vertices = (ucs.to_ocs(vertex) for vertex in vertices)
return list(vertices)
def approximate(self,
segments: int = 40,
ucs: 'UCS' = None) -> List['Vertex']:
if self.closed:
spline = BSplineClosed(self.control_points, order=self.degree + 1)
else:
spline = BSpline(self.control_points, order=self.degree + 1)
vertices = spline.approximate(segments)
if ucs is not None:
vertices = (ucs.to_ocs(vertex) for vertex in vertices)
return list(vertices)
def render_closed_bspline(self, layout: 'BaseLayout', degree: int = 3, dxfattribs: dict = None) -> None:
"""
Render a closed uniform BSpline as 3D :class:`~ezdxf.entities.Polyline`. Definition points are control points.
Args:
layout: :class:`~ezdxf.layouts.BaseLayout` object
degree: degree of B-spline (order = `degree` + 1)
dxfattribs: DXF attributes for :class:`~ezdxf.entities.Polyline`
"""
spline = BSplineClosed(self.points, order=degree + 1)
layout.add_polyline3d(list(spline.approximate(self.segments)), dxfattribs=dxfattribs)
def render_closed_bspline(self, layout: 'GenericLayoutType', degree: int = 3, dxfattribs: dict = None) -> None:
"""
Render a closed uniform BSpline as 3d polyline. Definition points are control points.
Args:
layout: ezdxf layout
degree: B-spline degree (order = degree + 1)
dxfattribs: DXF attributes for POLYLINE
"""
spline = BSplineClosed(self.points, order=degree + 1)
layout.add_polyline3d(list(spline.approximate(self.segments)), dxfattribs=dxfattribs)
def render_closed_rbspline(self, layout: 'GenericLayoutType', weights: Iterable[float], degree: int = 3,
dxfattribs: dict = None) -> None:
"""
Render a rational BSpline as 3d polyline.
Args:
layout: ezdxf layout
weights: list of weights, requires a weight value for each defpoint.
degree: B-spline degree (order = degree + 1)
dxfattribs: DXF attributes for POLYLINE
"""
spline = BSplineClosed(self.points, order=degree + 1, weights=weights)
layout.add_polyline3d(list(spline.approximate(self.segments)), dxfattribs=dxfattribs)
def render_closed_rbspline(self, layout: 'BaseLayout', weights: Iterable[float], degree: int = 3,
dxfattribs: dict = None) -> None:
"""
Render a rational BSpline as 3D :class:`~ezdxf.entities.Polyline`. Definition points are control
points.
Args:
layout: :class:`~ezdxf.layouts.BaseLayout` object
weights: list of weights, requires a weight value (float) for each definition point.
degree: degree of B-spline (order = `degree` + 1)
dxfattribs: DXF attributes for :class:`~ezdxf.entities.Polyline`
"""
spline = BSplineClosed(self.points, order=degree + 1, weights=weights)
layout.add_polyline3d(list(spline.approximate(self.segments)), dxfattribs=dxfattribs)