B Spline3D

Class full path: NemAll_Python_Geometry.BSpline3D

Bases: PolyPoints3D

class for 3D (non uniform, rational) B-spline geometry

Attributes

Degree: int property writable

Gets spline degree

IsPeriodic: bool property writable

Returns whether the spline is periodic

Returns only given flag which was originally set

Knots: NemAll_Python_Utility.VecDoubleList property writable

Get knot vector

Weights: NemAll_Python_Utility.VecDoubleList property writable

Get control points weights

Functions

Clear()

Clear data, getting invalid state

Create(curve_object) staticmethod

Create BSpline from ICurve3D

Parameters:

Name	Type	Description	Default
curve_object	object	Input curve	required

Returns:

Type	Description
BSpline3D	Created BSpline3D.

CreateArc3D(arc) staticmethod

Create BSpline form Arc3D

Parameters:

Name	Type	Description	Default
arc	Arc3D	Input arc	required

Returns:

Type	Description
BSpline3D	Created Bspline3D

CreateBSpline(points, degree, isPeriodic) staticmethod

Create BSpline from control points

Parameters:

Name	Type	Description	Default
points	Point3DList	Control points	required
degree	int	Degree of BSpline	required
isPeriodic	bool	true if BSpline should be smoothly closed	required

Returns:

Type	Description
BSpline3D	BSpline object

CreateBSpline3DFrom2DCurves(directionCurve_object, elevationCurve_object, startHeight, chainPoints) staticmethod

Creates BSpline3D from direction 2D curve and elevation 2D curve

Parameters:

Name	Type	Description	Default
directionCurve_object	object	direction curve ( for X,Y coordinates)	required
elevationCurve_object	object	elevation curve (for Z coordinates)	required
startHeight	float	Z coordinate of new curve start point	required
chainPoints	Point3DList	list of chain points to match resulting curve	required

Returns:

Type	Description
eGeometryErrorCode	tuple(eOK if successful,
BSpline3D	created BSpline3D)

CreateBSpline3DFromAxisAndGradient(directionCurve_object, elevationCurve_object, startHeight, chainPoints) staticmethod

Create BSpline3D curve from axis and gradient (all placed in XY plane)

Parameters:

Name	Type	Description	Default
directionCurve_object	object	direction/axis curve	required
elevationCurve_object	object	elevation/gradient curve	required
startHeight	float	Z coordinate of new curve start point	required
chainPoints	Point3DList	list of chain points to match resulting curve	required

Returns:

Type	Description
eGeometryErrorCode	tuple(error code,
BSpline3D	result BSpline3D curve)

CreateBSplineInterpolated(points, degree, isPeriodic) staticmethod

Create BSpline from interpolated points

Parameters:

Name	Type	Description	Default
points	Point3DList	Interpolated points	required
degree	int	Degree of BSpline	required
isPeriodic	bool	true if BSpline should be smoothly closed	required

Returns:

Type	Description
BSpline3D	BSpline object

CreateBSplineJoined(curves_object) staticmethod

Create BSpline by joining curves. Curves should meet by end points.

Parameters:

Name	Type	Description	Default
curves_object	list	Source curves	required

Returns:

Type	Description
BSpline3D	BSpline object (empty, if joining failed)

CreateLine3D(line) staticmethod

Create BSpline3D from Line3D

Parameters:

Name	Type	Description	Default
line	Line3D	Input line.	required

Returns:

Type	Description
BSpline3D	Created BSpline3D.

CreatePolyline3D(polyline3d) staticmethod

Create a BSpline out of a Polyline3D object

Parameters:

Name	Type	Description	Default
polyline3d	Polyline3D	Polyline3D that will be used for conversion	required

Returns:

Type	Description
BSpline3D	An instance of the created BSpline3D

CreateSpline(spline) staticmethod

Create BSpline from Spline3D

Parameters:

Name	Type	Description	Default
spline	Spline3D	Spline	required

Returns:

Type	Description
BSpline3D	Created BSpline3D.

EvaluateEndPoint()

Evaluate end point of bspline

Returns:

Type	Description
tuple[eGeometryErrorCode, Point3D]	evaluated end point

EvaluateEndRelPoint()

Evaluate relative end (last) point of bspline

Returns:

Type	Description
tuple[eGeometryErrorCode, Point3D]	evaluated relative end point

EvaluatePoint(param)

Evaluate point of b-spline

Parameters:

Name	Type	Description	Default
param	float	parameter to evaluate point on b-spline	required

Returns:

Type	Description
eGeometryErrorCode	tuple(error code of evaluation,
Point3D	resulting point, if succeeded)

EvaluatePointsWithTangents(parameters)

Evaluate points and tangents of b-spline

Parameters:

Name	Type	Description	Default
parameters	VecDoubleList	parameters to evaluate points and tangents on b-spline	required

Returns:

Type	Description
tuple[Point3D, Vector3D]	vector of resulting points and tangents, if calculation failed for any parameter, empty vector is returned

EvaluateStartPoint()

Evaluate start point of bspline

Returns:

Type	Description
tuple[eGeometryErrorCode, Point3D]	evaluated start point

EvaluateStartRelPoint()

Evaluate relative start point of bspline

Returns:

Type	Description
tuple[eGeometryErrorCode, Point3D]	evaluated relative start point

Get()

Return type: tuple(Point3DList, VecDoubleList, VecDoubleList, int, bool)

GetDegree()

Gets spline degree

Returns:

Type	Description
int	spline degree

GetInterpolatedPoints()

Function returns interpolated points of b-spline

Returns:

Type	Description
Point3DList	list of interpolated points

GetInterpolatedPointsParameters()

Function returns list of parameters for interpolated points of b-spline

Returns:

Type	Description
VecDoubleList	list of parameters of interpolated points

GetInterval()

Function returns the interval of bspline

Returns:

Type	Description
bool	tuple(true if success,
float	start of curve interval,
float	end of curve interval)

GetKnotMultiplicities()

Get knot vector and knot multiplicities

Returns:

Type	Description
VecDoubleList	tuple(knot vector with unique values,
VecSizeTList	knot multiplicities)

GetKnots()

Get knot vector

Returns:

Type	Description
VecDoubleList	knot vector

GetParametersForDistances(distances)

Find parameters for distances on b-spline

Parameters:

Name	Type	Description	Default
distances	VecDoubleList	list of distances to calculate parameters for	required

Returns:

Type	Description
VecDoubleList	list of parameters, if calculation failed for any distance, empty vector is returned

GetWeights()

Get control points weights

Returns:

Type	Description
VecDoubleList	weights vector

IsClosed()

Check if spline is closed ( first/last points are equal )

Returns:

Type	Description
bool	closed spline true/false

IsEndClamped()

Function returns whether the bspline is clamped at the end

Returns:

Type	Description
bool	true if clamped on end

IsLine()

Check if bspline is line

Returns:

Type	Description
bool	Returns true if it is line

IsPeriodicClosed()

Returns whether the spline is periodic or closed in 1st degree

BSpline with degree == 1 cannot be periodic, wherefore returns true if closed.

Returns:

Type	Description
bool	bool true = periodic or closed

IsRational()

Check if the spline is rational

Returns:

Type	Description
bool	bool true = rational

IsStartClamped()

Function returns whether the bspline is clamped at the start

Returns:

Type	Description
bool	true if clamped on start

IsValid()

Check spline validity

Returns:

Type	Description
bool	bool valid = true

Reverse()

Reverse of current spline

Method reverse Spline using reverse from PolyPoints and swapping tangents.

Set(points, weights, knots, degree, isPeriodic=False)

Get/Set functions

Parameters:

Name	Type	Description	Default
points	Point3DList		required
weights	VecDoubleList		required
knots	VecDoubleList		required
degree	int		required
isPeriodic	bool		False

SetDegree(degree)

Set spline degree

Parameters:

Name	Type	Description	Default
degree	int	desired degree	required

SetKnots(knots)

Set knot vector

Parameters:

Name	Type	Description	Default
knots	VecDoubleList	knot vector to set	required

SetPeriodic(periodic)

Set periodic flag

Parameters:

Name	Type	Description	Default
periodic	bool	value of periodic flag	required

SetWeights(weights)

Set weights for control points

Parameters:

Name	Type	Description	Default
weights	VecDoubleList	weights vector to set	required

__eq__(bspline)

Comparison of bsplines without tolerance.

Be careful, this method work without tolerance!

Parameters:

Name	Type	Description	Default
bspline	BSpline3D	Compared bspline.	required

Returns:

Type	Description
object	True when bsplines are equal, otherwise false.

__init__ overload

__init__()

Initialize

__init__(points, weights, knots, degree, isPeriodic)

Default constructor. Creates invalid spline.

Parameters:

Name	Type	Description	Default
points	Point3DList		required
weights	VecDoubleList		required
knots	VecDoubleList		required
degree	int		required
isPeriodic	bool		required

__init__(spline)

Copy constructor.

Parameters:

Name	Type	Description	Default
spline	BSpline3D	Spline which will be copied.	required

__repr__()

Convert to string