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: VecDoubleList property writable

Get knot vector

Weights: 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	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	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	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()

Gets the BSpline3D

Returns:

Type	Description
Point3DList	spline points
VecDoubleList	vector with weights
VecDoubleList	vector with knots
int	spline degree
bool	True if spline is periodic, False otherwise

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	true if success,
float	start of curve interval,
float	end of curve interval)

GetKnotMultiplicities()

Get knot vector and knot multiplicities

Returns:

Type	Description
VecDoubleList	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	spline points	required
weights	VecDoubleList	vector with spline weights	required
knots	VecDoubleList	vector with spline knots	required
degree	int	spline degree	required
isPeriodic	bool	Whether the spline is to be periodic	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