`SketchNurbs`#

class ansys.geometry.core.sketch.nurbs.SketchNurbs#

Bases: ansys.geometry.core.sketch.edge.SketchEdge

Represents a NURBS sketch curve.

Warning

NURBS sketching is only supported in 26R1 and later versions of Ansys.

Notes

This class is a wrapper around the NURBS curve class from the geomdl library. By leveraging the geomdl library, this class provides a high-level interface to create and manipulate NURBS curves. The geomdl library is a powerful library for working with NURBS curves and surfaces. For more information, see https://pypi.org/project/geomdl/.

Overview#

Constructors

`fit_curve_from_points`	Fit a NURBS curve to a set of points.
`from_control_points`	Create a NURBS curve from control points.
`from_json_file`	Create NURBS sketch curve(s) from a JSON file or JSON string.
`to_json_file`	Serialize one or more NURBS sketch curves to a JSON file.
`partial_ellipse`	Create an exact rational NURBS for a partial ellipse arc.

Methods

contains_point

Check if the curve contains a given point within a specified tolerance.

Properties

`geomdl_nurbs_curve`	Get the underlying NURBS curve.
`control_points`	Get the control points of the curve.
`degree`	Get the degree of the curve.
`knots`	Get the knot vector of the curve.
`weights`	Get the weights of the control points.
`start`	Get the start point of the curve.
`end`	Get the end point of the curve.
`visualization_polydata`	Get the VTK polydata representation for PyVista visualization.

Import detail#

from ansys.geometry.core.sketch.nurbs import SketchNurbs

Property detail#

property SketchNurbs.geomdl_nurbs_curve: geomdl.NURBS.Curve#

Get the underlying NURBS curve.

Notes

This property gives access to the full functionality of the NURBS curve coming from the geomdl library. Use with caution.

property SketchNurbs.control_points: list[ansys.geometry.core.math.point.Point2D]#: Get the control points of the curve.

property SketchNurbs.degree: int#: Get the degree of the curve.

property SketchNurbs.knots: list[ansys.geometry.core.typing.Real]#: Get the knot vector of the curve.

property SketchNurbs.weights: list[ansys.geometry.core.typing.Real]#: Get the weights of the control points.

property SketchNurbs.start: ansys.geometry.core.math.point.Point2D#: Get the start point of the curve.

property SketchNurbs.end: ansys.geometry.core.math.point.Point2D#: Get the end point of the curve.

property SketchNurbs.visualization_polydata: pyvista.PolyData#

Get the VTK polydata representation for PyVista visualization.

Returns:

pyvista.PolyData: VTK pyvista.Polydata configuration.

Notes

The representation lies in the X/Y plane within the standard global Cartesian coordinate system.

Method detail#

SketchNurbs.contains_point(point: ansys.geometry.core.math.point.Point2D, tol: float = 1e-06) → bool#

Check if the curve contains a given point within a specified tolerance.

Parameters:

pointPoint2D: The point to check.
tolfloat, optional: The tolerance for the containment check, by default 1e-6.

Returns:

bool: True if the curve contains the point within the tolerance, False otherwise.

classmethod SketchNurbs.fit_curve_from_points(points: list[ansys.geometry.core.math.point.Point2D], degree: int = 3) → SketchNurbs#

Fit a NURBS curve to a set of points.

Parameters:

pointslist[Point2D]: The points to fit the curve to.
degreeint, optional: The degree of the NURBS curve, by default 3.

Returns:

SketchNurbs: A new instance of SketchNurbs fitted to the given points.

classmethod SketchNurbs.from_control_points(control_points: list[ansys.geometry.core.math.point.Point2D], degree: int, knots: list[ansys.geometry.core.typing.Real], weights: list[ansys.geometry.core.typing.Real] | None = None) → SketchNurbs#

Create a NURBS curve from control points.

Parameters:

control_pointslist[Point2D]: Control points of the curve.
degreeint: Degree of the curve.
knotslist[Real]: Knot vector of the curve.
weightslist[Real], optional: Weights of the control points.

Returns:

SketchNurbs: NURBS curve.

classmethod SketchNurbs.from_json_file(source: str | pathlib.Path, elements: list[str] | None = None) → SketchNurbs | dict[str, SketchNurbs]#

Create NURBS sketch curve(s) from a JSON file or JSON string.

Parameters:

sourceUnion[str, Path]: JSON file path, or a raw JSON string.
elementslist[str], optional: Names of the elements to build. If omitted, every element found in the JSON is built.

Returns:

Union[SketchNurbs, dict[str, SketchNurbs]]: A single SketchNurbs if one element is requested, or a dictionary of SketchNurbs keyed by element name if multiple elements are requested.

Raises:

ValueError: If any requested element is missing from the JSON data.

classmethod SketchNurbs.to_json_file(curves: dict[str, SketchNurbs], path: str | pathlib.Path) → pathlib.Path#

Serialize one or more NURBS sketch curves to a JSON file.

Parameters:

curvesdict[str, SketchNurbs]: Mapping of element name to the SketchNurbs to serialize under that name, e.g. {“hub_0”: curve_1, “hub_1”: curve_2}.
pathUnion[str, Path]: File path to write the JSON to. Required.

Raises:

ValueError: If path is not provided, or curves is empty.

Create an exact rational NURBS for a partial ellipse arc.

Parameters:

centerPoint2D: Center of the ellipse.
major_radiusQuantity | Distance | Real: Semi-major axis length (x-direction before rotation).
minor_radiusQuantity | Distance | Real: Semi-minor axis length (y-direction before rotation).
start_angleQuantity | Angle | Real: Parametric start angle. Defaults to radians when given as a Real.
end_angleQuantity | Angle | Real: Parametric end angle. Defaults to radians when given as a Real. The arc sweeps counter-clockwise when end_angle > start_angle.
angleQuantity | Angle | Real, default: 0: Rotation of the ellipse about its center (radians when Real).

Returns:

SketchNurbs: Exact rational quadratic NURBS (degree 2) for the requested arc. The arc is split into segments of at most 90° for numerical stability.

Raises:

ValueError: If either radius is non-positive.
ValueError: If start_angle equals end_angle (zero-length arc).