The NURBS curve fit tool creates a NURBS curve that approximates an existing curve. The ON_NurbsCurveFitParameters class contains the paramters that determine NURBS curve properties (degree, point count, ...) and other fitting contstraints. More...

#include <opennurbs_plus_rebuild.h>

Public Types
enum	: int { MinimumDegree = 1, MaximumDegree = 11, DefaultDegree = 3, MinimumClampedPointCount = 2, MinimumClosedPointCount = 3, MaximumPointCount = 3000, DefaultSampleCount = ON_PointPairing::DefaultPointCount, MinimumSampleCount = (ON_NurbsCurveFitParameters::DefaultSampleCount / 10), MaximumSampleCount = (10 * ON_NurbsCurveFitParameters::DefaultSampleCount) }

enum	Intensity : unsigned char { Intensity::None = 0, Intensity::Low = 1, Intensity::Moderate = 2, Intensity::Medium = 3, Intensity::High = 4, Intensity::Extreme = 5, Intensity::Custom = 6 }
	The Intensity enum is used to select a predefined or a custom value for the smoothing, uniformity, and curvature bias coefficients. More...

enum	KinkSplit : unsigned char { KinkSplit::None = 0, KinkSplit::AtG1Changes = 1, KinkSplit::AtLargeG2Changes = 2, KinkSplit::AtMediumG2Changes = 3, KinkSplit::AtSmallG2Changes = 4 }
	The KinkSplit enum is used to determine how target curve kinks (abrupt changes in target or curvature) are handled during rebuilding. More...

enum	TangentMatch : unsigned char { TangentMatch::None = 0, TangentMatch::AtStart = 1, TangentMatch::AtEnd = 2, TangentMatch::AtStartAndEnd = 3 }
	The TangentMatch enum is used to constrain the tangents of the rebuilt curve to match those of the target curve. More...

Public Member Functions
	ON_NurbsCurveFitParameters ()=default

	ON_NurbsCurveFitParameters (const ON_NurbsCurveFitParameters &)=default

	~ON_NurbsCurveFitParameters ()=default

bool	ApplyTangentMatchingAtKinks () const
	Control when tangent matching is applied at kinks. Note that this setting does somthing only when some tangent matching option is true and the input curve has kinks. More...

int	ClampedControlPointCount () const

bool	Closed () const

int	ConstrainedPointCount () const
	If Closed() is true, the number of constrained points is (TangentMatchStart() \|\| TangentMatchEnd() ? 1 : 0) More...

double	CurvatureBiasCoefficient () const

ON_NurbsCurveFitParameters::Intensity	CurvatureBiasIntensity () const
	Curvature bias adds a bias to fit target points with relatively higher curvatures more closely. Use CurvatureBiasCoefficient() to get the numerical coefficient used in the objective function. Use SetCurvatureBiasCoefficient() to set a custom curvature bias coefficient. More...

int	Degree () const

void	GetPointCountRange (int &minimum_point_count, int &maximum_point_count, double &tolerance) const

const ON_SHA1_Hash	Hash (bool bHashTangentMatching, bool bHashKinkSplitting) const
	Returns a hash of the options that control the output curve geometry. These options are: degree (degree of the output curves), point_count (number of user control points in the output curves), sample_point_count (number of points sampled from the input curves). smoothing When bShowTangentOptions is true, end tangent matching settings are hashed. When bShowSplitAtKinksOption is true, kink parameters are hashed. This hash is useful for determing when previously calculated output curves need to be updated by comparing the hash current options and the hash of options used to calculate the output curves. More...

double	KinkAngleDegrees () const

double	KinkAngleRadians () const

const ON_CurveKinkDefinition	KinkDefinition () const
	When kink splitting is enabled, the kink definition determines what type of target curve tangent of curvature change is considered to be a kink. More...

ON_NurbsCurveFitParameters::KinkSplit	KinkSplitting () const

ON_NurbsCurveFitParameters &	operator= (const ON_NurbsCurveFitParameters &)=default

bool	OptimizeCurve () const

int	PeriodicControlPointCount () const

int	PointCount () const
	Number of distinct control points in the NURBS curve fit. If a range of point counts is possible, this is the minimum number. More...

const ON_2dex	PointCountRange () const
	Get the point count range as an ON_2dex. More...

int	PointCountRangeMaximum () const

int	PointCountRangeMinimum () const

double	PointCountRangeTolerance () const
	When a range of point counts is permitted and PointCountRangeTolerance() > 0, then searching for the NURBS curve fit terminates if the separation is &lt= PointCountRangeTolerance(). More...

class ON_ProgressReporter *	ProgressReporter () const

int	SampleCount () const

void	SetApplyTangentMatchingAtKinks (bool bApplyTangentMatchingAtKinks)
	Control when tangent matching is applied at kinks. Note that this setting does somthing only when some tangent matching option is true and the input curve has kinks. More...

void	SetClosed (bool bClosed)
	Generally, it is best to call SetClosed() once before setting any other options and to leave it unchanged while the other options are adjusted. This is because the relationship betweem the point count and degree options are different for periodic and non-periodic NURBS curves. If every curve created with these options will be closed, then call SetClosed(true). Otherwise call SetClosed(false). More...

void	SetCurvatureBiasCoefficient (double curvature_bias_coefficient)
	Specify a curvature bias coefficient. Positive curvature bias coefficients make the fit curve relatively closer to the target curve in regions where the target curve has relatively higher curvature. In general, use the smallest value that gives the desired result. More...

void	SetCurvatureBiasIntensity (ON_NurbsCurveFitParameters::Intensity curvature_bias_intensity)
	Use one of ON_NurbsCurveFitParameters::Intensity enum values to specify a curvature bias. This method is provided to make it easier to provide an interface that lets a user select reasonable values for the curvature bias coefficient without having to understand the objective function. Positive curvature bias coefficients make the fit curve closer to regions in the target curve with relatively higher curvature. In general, use the smallest value that gives the desired result. More...

void	SetDegree (int degree)

void	SetKinkAngleDegrees (double kink_angle_degrees)

void	SetKinkAngleRadians (double kink_angle_radians)

void	SetKinkSplitting (ON_NurbsCurveFitParameters::KinkSplit kink_splitting)

void	SetOptimizeCurve (bool bOptimizeCurve)

void	SetPointCount (int point_count)
	Sets the point count and, if necessary, reduces the degree so that degree that degree <= ON_NurbsCurveFitParameters::MaximumDegree(point_count, Closed()). More...

void	SetPointCountRange (int minimum_point_count, int maximum_point_count)
	Use SetPointCountRange() if you want the NURBS curve fit with the smallest separation having the point count in the specified range. More...

void	SetPointCountRange (int minimum_point_count, int maximum_point_count, double tolerance)
	Use SetPointCountRange() if you want the NURBS curve fit with the smallest separation having the point count in the specified range. This version of SetPointCountRange() lets you also specify a tolerance. More...

void	SetProgressReporter (class ON_ProgressReporter *progress_reporter)

void	SetSampleCount (int sample_count)

void	SetSmoothingCoefficient (double smoothing_coefficient)
	Specify a smoothing coefficient. More...

void	SetSmoothingIntensity (ON_NurbsCurveFitParameters::Intensity smoothing_intensity)
	Use one of the one of ON_NurbsCurveFitParameters::Intensity enum values to specify a smoothing coefficient. This method is provided to make it easier to provide an interface that lets a user select reasonable values for the smoothing penalty without having to understand the objective fuction calculation. More...

void	SetSubDFriendly (bool bSubDFriendly)

void	SetTangentMatching (ON_NurbsCurveFitParameters::TangentMatch tangent_matching)

void	SetTerminator (class ON_Terminator *terminator)

void	SetUniformityCoefficient (double uniformity_coefficient)
	Specify a uniformity coefficient. Positive uniformity coefficients make the distances between control points more uniform. In general, use the smallest value that gives the desired result. More...

void	SetUniformityIntensity (ON_NurbsCurveFitParameters::Intensity uniformity_intensity)
	Use one of ON_NurbsCurveFitParameters::Intensity enum values to specify a uniformity coefficient. This method is provided to make it easier to provide an interface that lets a user select reasonable values for the uniformity coefficient without having to understand the optimization calculation. Positive uniformity coefficients make the distances between control points more uniform. In general, use the smallest value that gives the desired result. More...

double	SmoothingCoefficient () const

ON_NurbsCurveFitParameters::Intensity	SmoothingIntensity () const
	The smoothing penalty in the objective function penalizes triplets of contiguous control points that are not colinear and equally spaced. Use SmoothingCoefficient() to get the numerical coefficient used in the objective function. Use SetSmoothingCoefficient() to set a custom smoothing coefficient. More...

bool	SubDFriendly () const

ON_NurbsCurveFitParameters::TangentMatch	TangentMatching () const

bool	TerminationRequested () const

class ON_Terminator *	Terminator () const

double	UniformityCoefficient () const

ON_NurbsCurveFitParameters::Intensity	UniformityIntensity () const
	The uniformity penalty in the objective function penalizes variation in the distances between control points. Use UniformityCoefficient() to get the numerical coefficient used in the objective function. Use SetUniformityCoefficient() to set a custom uniformity penalty coefficient. More...

bool	VariablePointCount () const

Static Public Member Functions
static ON_NurbsCurveFitParameters::Intensity	IntensityFromInt (int intensity_as_int, ON_NurbsCurveFitParameters::Intensity invalid_input_result)

static ON_NurbsCurveFitParameters::KinkSplit	KinkSplitFromInt (int kink_split_as_int, ON_NurbsCurveFitParameters::KinkSplit invalid_input_result)
	Convert an integer value to the ON_NurbsCurveFitParameters::KinkSplit enum with the same value. More...

static int	MaximumDegreeForPointCount (int point_count, bool bClosed, bool bSubDFreiendly)
	Given a point count and periodic setting, determine the maximum degree. More...

static int	MinimumPointCountForDegree (int degree, bool bClosed, bool bSubDFreiendly)
	Give a degree and periodic setting, determine the minimum point count. More...

static ON_NurbsCurveFitParameters::TangentMatch	TangentMatchFromInt (int tangent_match_as_int, ON_NurbsCurveFitParameters::TangentMatch invalid_input_result)
	Convert an integer value to the ON_NurbsCurveFitParameters::TangentMatch enum with the same value. More...

static bool	ValidInput (size_t sample_point_count, unsigned degree, unsigned control_point_count, bool bClosed, ON_Interval curve_domain)

Static Public Attributes
static constexpr double	ExtremeCurvatureBiasCoefficient = 10.0
	Curvature bias coefficient that corresponds to ON_NurbsCurveFitParameters::Intensity::High. More...

static constexpr double	ExtremeSmoothingCoefficient = 10.0
	Smoothing coefficient that corresponds to ON_NurbsCurveFitParameters::Intensity::Extreme. More...

static constexpr double	ExtremeUniformityCoefficient = 10.0
	Uniformity coefficient that corresponds to ON_NurbsCurveFitParameters::Intensity::High. More...

static constexpr double	HighCurvatureBiasCoefficient = 1.0
	Curvature bias coefficient that corresponds to ON_NurbsCurveFitParameters::Intensity::High. More...

static constexpr double	HighSmoothingCoefficient = 1.0
	Smoothing coefficient that corresponds to ON_NurbsCurveFitParameters::Intensity::High. More...

static constexpr double	HighUniformityCoefficient = 1.0
	Uniformity coefficient that corresponds to ON_NurbsCurveFitParameters::Intensity::High. More...

static constexpr double	LowCurvatureBiasCoefficient = 0.001
	Curvature bias coefficient that corresponds to ON_NurbsCurveFitParameters::Intensity::Low. More...

static constexpr double	LowSmoothingCoefficient = 0.001
	Smoothing coefficient that corresponds to ON_NurbsCurveFitParameters::Intensity::Low. More...

static constexpr double	LowUniformityCoefficient = 0.001

static constexpr double	MaximumCurvatureBiasCoefficient = 10.0
	Maximum permitted curvature bias coefficient. More...

static constexpr double	MaximumSmoothingCoefficient = 10.0
	Maximum permitted smoothing coefficient. More...

static constexpr double	MaximumUniformityCoefficient = 10.0
	Maximum permitted uniformity coefficient. More...

static constexpr double	MediumCurvatureBiasCoefficient = 0.1
	Curvature bias coefficient that corresponds to ON_NurbsCurveFitParameters::Intensity::Medium. More...

static constexpr double	MediumSmoothingCoefficient = 0.1
	Smoothing coefficient that corresponds to ON_NurbsCurveFitParameters::Intensity::Medium. More...

static constexpr double	MediumUniformityCoefficient = 0.1
	Uniformity coefficient that corresponds to ON_NurbsCurveFitParameters::Intensity::Medium. More...

static constexpr double	ModerateCurvatureBiasCoefficient = 0.01
	Curvature bias coefficient that corresponds to ON_NurbsCurveFitParameters::Intensity::Moderate. More...

static constexpr double	ModerateSmoothingCoefficient = 0.01
	Smoothing coefficient that corresponds to ON_NurbsCurveFitParameters::Intensity::Moderate. More...

static constexpr double	ModerateUniformityCoefficient = 0.01

Detailed Description

The NURBS curve fit tool creates a NURBS curve that approximates an existing curve. The ON_NurbsCurveFitParameters class contains the paramters that determine NURBS curve properties (degree, point count, ...) and other fitting contstraints.

THIS SOFTWARE IS PROVIDED "AS IS" WITHOUT EXPRESS OR IMPLIED WARRANTY. ALL IMPLIED WARRANTIES OF FITNESS FOR ANY PARTICULAR PURPOSE AND OF MERCHANTABILITY ARE HEREBY DISCLAIMED.

For complete openNURBS copyright information see http://www.opennurbs.org.

Member Enumeration Documentation

◆ anonymous enum

anonymous enum : int

Enumerator
MinimumDegree
MaximumDegree
DefaultDegree
MinimumClampedPointCount
MinimumClosedPointCount
MaximumPointCount
DefaultSampleCount
MinimumSampleCount	Minimum number of points to sample from input curves and pass to the fitter that creates the output NURBS curve.
MaximumSampleCount	Maximum number of points to sample from input curves and pass to the fitter that creates the output NURBS curve.

◆ Intensity

enum ON_NurbsCurveFitParameters::Intensity : unsigned char

strong

The Intensity enum is used to select a predefined or a custom value for the smoothing, uniformity, and curvature bias coefficients.

Enumerator
None
Low
Moderate
Medium
High
Extreme
Custom

◆ KinkSplit

enum ON_NurbsCurveFitParameters::KinkSplit : unsigned char

strong

The KinkSplit enum is used to determine how target curve kinks (abrupt changes in target or curvature) are handled during rebuilding.

Enumerator
None	All target curve kinks are ignored and rebuilt curves will be G2.
AtG1Changes	The rebuilt curve is permitted have a tangent change at locations where the target curve has tangent changes. Curvature changes in the target curve are ignored.
AtLargeG2Changes	The rebuilt curve is permitted have a tangent or curvature changes at locations where the target curve has a tangent or large curvature changes.
AtMediumG2Changes	The rebuilt curve is permitted have a tangent or curvature changes at locations where the target curve has a tangent or medium curvature changes.
AtSmallG2Changes	The rebuilt curve is permitted have a tangent or curvature changes at locations where the target curve has a tangent or small curvature changes. This option is the most sensitive to splitting at any tangent or curvature kink.

◆ TangentMatch

enum ON_NurbsCurveFitParameters::TangentMatch : unsigned char

strong

The TangentMatch enum is used to constrain the tangents of the rebuilt curve to match those of the target curve.

Enumerator
None	Ignore target curve start and end tangent directions.
AtStart	Match the target curve start tangent direction.
AtEnd	Match the target curve end tangent direction.
AtStartAndEnd	Match the target curve start and end tangent direction.

Constructor & Destructor Documentation

◆ ON_NurbsCurveFitParameters() [1/2]

ON_NurbsCurveFitParameters::ON_NurbsCurveFitParameters ( )

default

◆ ~ON_NurbsCurveFitParameters()

ON_NurbsCurveFitParameters::~ON_NurbsCurveFitParameters ( )

default

◆ ON_NurbsCurveFitParameters() [2/2]

ON_NurbsCurveFitParameters::ON_NurbsCurveFitParameters ( const ON_NurbsCurveFitParameters & )

default

Member Function Documentation

◆ ApplyTangentMatchingAtKinks()

bool ON_NurbsCurveFitParameters::ApplyTangentMatchingAtKinks ( ) const

Control when tangent matching is applied at kinks. Note that this setting does somthing only when some tangent matching option is true and the input curve has kinks.

Returns: If true, the TangentMatchStart() and TangentMatchEnd() settings are applied at kinks. Otherwise, the tangent matching applies only to the ends of curves.

◆ ClampedControlPointCount()

int ON_NurbsCurveFitParameters::ClampedControlPointCount ( ) const

Number of control points if the NURBS curve will be clamped. Number of total control points if the NURBS curve will be periodic. This number is >= PointCount() Includes SubDFriendly constrained points and the duplicated point for a clamped closed curve.

◆ Closed()

bool ON_NurbsCurveFitParameters::Closed ( ) const

Returns: True if every curve created with these options will be periodic.

◆ ConstrainedPointCount()

int ON_NurbsCurveFitParameters::ConstrainedPointCount ( ) const

If Closed() is true, the number of constrained points is (TangentMatchStart() || TangentMatchEnd() ? 1 : 0)

(TangentMatchStart()?1:0)
(TangentMatchEnd()?1:0). If Closed() is false, the number of constrained points is 2
(SubDFriendly() ? 2 : 0)
(TangentMatchStart()?1:0)
(TangentMatchEnd()?1:0).

Returns: Number of constrained points.

◆ CurvatureBiasCoefficient()

double ON_NurbsCurveFitParameters::CurvatureBiasCoefficient ( ) const

◆ CurvatureBiasIntensity()

ON_NurbsCurveFitParameters::Intensity ON_NurbsCurveFitParameters::CurvatureBiasIntensity ( ) const

Curvature bias adds a bias to fit target points with relatively higher curvatures more closely. Use CurvatureBiasCoefficient() to get the numerical coefficient used in the objective function. Use SetCurvatureBiasCoefficient() to set a custom curvature bias coefficient.

Returns: The intensity of the curvature bias in the objective function.

◆ Degree()

int ON_NurbsCurveFitParameters::Degree ( ) const

◆ GetPointCountRange()

void ON_NurbsCurveFitParameters::GetPointCountRange	(	int &	minimum_point_count,
		int &	maximum_point_count,
		double &	tolerance
	)		const

◆ Hash()

const ON_SHA1_Hash ON_NurbsCurveFitParameters::Hash	(	bool	bHashTangentMatching,
		bool	bHashKinkSplitting
	)		const

Returns a hash of the options that control the output curve geometry. These options are: degree (degree of the output curves), point_count (number of user control points in the output curves), sample_point_count (number of points sampled from the input curves). smoothing When bShowTangentOptions is true, end tangent matching settings are hashed. When bShowSplitAtKinksOption is true, kink parameters are hashed. This hash is useful for determing when previously calculated output curves need to be updated by comparing the hash current options and the hash of options used to calculate the output curves.

Parameters

bHashTangentMatching	If the set of input curves contain at least one that is open, then pass true to include end tangent matching settings in the hash.
bHashKinkSplitting	If the set of input curves have kinks, then pass true to include kink splitting settings in the hash.

Returns: A hash of the options that control the output curve geometry.

◆ IntensityFromInt()

static ON_NurbsCurveFitParameters::Intensity ON_NurbsCurveFitParameters::IntensityFromInt	(	int	intensity_as_int,
		ON_NurbsCurveFitParameters::Intensity	invalid_input_result
	)

static

◆ KinkAngleDegrees()

double ON_NurbsCurveFitParameters::KinkAngleDegrees ( ) const

◆ KinkAngleRadians()

double ON_NurbsCurveFitParameters::KinkAngleRadians ( ) const

◆ KinkDefinition()

const ON_CurveKinkDefinition ON_NurbsCurveFitParameters::KinkDefinition ( ) const

When kink splitting is enabled, the kink definition determines what type of target curve tangent of curvature change is considered to be a kink.

Returns: Current kink definition.

◆ KinkSplitFromInt()

static ON_NurbsCurveFitParameters::KinkSplit ON_NurbsCurveFitParameters::KinkSplitFromInt	(	int	kink_split_as_int,
		ON_NurbsCurveFitParameters::KinkSplit	invalid_input_result
	)

static

Convert an integer value to the ON_NurbsCurveFitParameters::KinkSplit enum with the same value.

Parameters

kink_split_as_int
invalid_input_result	If kink_split_as_int does not match an KinkSplit enum value, then this value is returned.

Returns

◆ KinkSplitting()

ON_NurbsCurveFitParameters::KinkSplit ON_NurbsCurveFitParameters::KinkSplitting ( ) const

Returns: Types of target curve kinks that get separate rebuilding on either side of the kink.

◆ MaximumDegreeForPointCount()

static int ON_NurbsCurveFitParameters::MaximumDegreeForPointCount	(	int	point_count,
		bool	bClosed,
		bool	bSubDFreiendly
	)

static

Given a point count and periodic setting, determine the maximum degree.

Parameters

point_count	Number of indpendent control points in the output NURBS curve.
bClosed	True if the output NURBS curve will be periodic.

Returns: Maximum permitted degree.

◆ MinimumPointCountForDegree()

static int ON_NurbsCurveFitParameters::MinimumPointCountForDegree	(	int	degree,
		bool	bClosed,
		bool	bSubDFreiendly
	)

static

Give a degree and periodic setting, determine the minimum point count.

Parameters

degree	Degree of output NURBS curve.
bClosed	True if the output NURBS curve will be closed.

Returns: Minimum permitted point count.

◆ operator=()

ON_NurbsCurveFitParameters& ON_NurbsCurveFitParameters::operator= ( const ON_NurbsCurveFitParameters & )

default

◆ OptimizeCurve()

bool ON_NurbsCurveFitParameters::OptimizeCurve ( ) const

◆ PeriodicControlPointCount()

int ON_NurbsCurveFitParameters::PeriodicControlPointCount ( ) const

Number of total control points if the NURBS curve will be periodic. This number is >= PointCount() and includes periodic duplicates.

◆ PointCount()

int ON_NurbsCurveFitParameters::PointCount ( ) const

Number of distinct control points in the NURBS curve fit. If a range of point counts is possible, this is the minimum number.

Returns: Number of distinct control points in the NURBS curve fit.

◆ PointCountRange()

const ON_2dex ON_NurbsCurveFitParameters::PointCountRange ( ) const

Get the point count range as an ON_2dex.

Returns: PointCountRange().i = PointCountRangeMinimum() PointCountRange().j = PointCountRangeMinimum()

◆ PointCountRangeMaximum()

int ON_NurbsCurveFitParameters::PointCountRangeMaximum ( ) const

Returns: Maximum number of distinct control points in the NURBS curve fit.

◆ PointCountRangeMinimum()

int ON_NurbsCurveFitParameters::PointCountRangeMinimum ( ) const

Returns: Minimum number of distinct control points in the NURBS curve fit.

◆ PointCountRangeTolerance()

double ON_NurbsCurveFitParameters::PointCountRangeTolerance ( ) const

When a range of point counts is permitted and PointCountRangeTolerance() > 0, then searching for the NURBS curve fit terminates if the separation is &lt= PointCountRangeTolerance().

Returns: The desired or target separation value used when a ranged of point counts is permitted.

◆ ProgressReporter()

class ON_ProgressReporter* ON_NurbsCurveFitParameters::ProgressReporter ( ) const

◆ SampleCount()

int ON_NurbsCurveFitParameters::SampleCount ( ) const

◆ SetApplyTangentMatchingAtKinks()

void ON_NurbsCurveFitParameters::SetApplyTangentMatchingAtKinks ( bool bApplyTangentMatchingAtKinks )

Control when tangent matching is applied at kinks. Note that this setting does somthing only when some tangent matching option is true and the input curve has kinks.

Parameters

bApplyTangentMatchAtKinks If true, the TangentMatchStart() and TangentMatchEnd() settings are applied at kinks. Otherwise, the tangent matching applies only to the ends of curves.

◆ SetClosed()

void ON_NurbsCurveFitParameters::SetClosed ( bool bClosed )

Generally, it is best to call SetClosed() once before setting any other options and to leave it unchanged while the other options are adjusted. This is because the relationship betweem the point count and degree options are different for periodic and non-periodic NURBS curves. If every curve created with these options will be closed, then call SetClosed(true). Otherwise call SetClosed(false).

Parameters

bClosed Pass true if every curve created with these options will be closed. Otherwise, pass false.

◆ SetCurvatureBiasCoefficient()

void ON_NurbsCurveFitParameters::SetCurvatureBiasCoefficient ( double curvature_bias_coefficient )

Specify a curvature bias coefficient. Positive curvature bias coefficients make the fit curve relatively closer to the target curve in regions where the target curve has relatively higher curvature. In general, use the smallest value that gives the desired result.

Parameters

uniformity_coefficient Valid values are in the range 0 <= uniformity_coefficient <= ON_NurbsCurveFitParameters::MaximumCurvatuerBiasCoefficient. If curvature_bias_coefficient is not valid, then curvature bias is set to ON_NurbsCurveFitParameters::Uniformity::None.

◆ SetCurvatureBiasIntensity()

void ON_NurbsCurveFitParameters::SetCurvatureBiasIntensity ( ON_NurbsCurveFitParameters::Intensity curvature_bias_intensity )

Use one of ON_NurbsCurveFitParameters::Intensity enum values to specify a curvature bias. This method is provided to make it easier to provide an interface that lets a user select reasonable values for the curvature bias coefficient without having to understand the objective function. Positive curvature bias coefficients make the fit curve closer to regions in the target curve with relatively higher curvature. In general, use the smallest value that gives the desired result.

Parameters

curvature_bias_intensity One of ON_NurbsCurveFitParameters::Intensity enum values. If ON_NurbsCurveFitParameters::Intensity::Custom is passed in and a preexisting custom curvature bias has not been specified using SetCurvatureBiasCoefficient(), then CurvatureBiasIntensity() is set to none. If you want to set a custom uniformity coefficient, use SetCurvatureBiasCoefficient(x).

◆ SetDegree()

void ON_NurbsCurveFitParameters::SetDegree ( int degree )

◆ SetKinkAngleDegrees()

void ON_NurbsCurveFitParameters::SetKinkAngleDegrees ( double kink_angle_degrees )

◆ SetKinkAngleRadians()

void ON_NurbsCurveFitParameters::SetKinkAngleRadians ( double kink_angle_radians )

◆ SetKinkSplitting()

void ON_NurbsCurveFitParameters::SetKinkSplitting ( ON_NurbsCurveFitParameters::KinkSplit kink_splitting )

Parameters

kink_splitting Specifies what type of target curve kinks get separate rebuilding on either side of the kink.

◆ SetOptimizeCurve()

void ON_NurbsCurveFitParameters::SetOptimizeCurve ( bool bOptimizeCurve )

◆ SetPointCount()

void ON_NurbsCurveFitParameters::SetPointCount ( int point_count )

Sets the point count and, if necessary, reduces the degree so that degree that degree <= ON_NurbsCurveFitParameters::MaximumDegree(point_count, Closed()).

Parameters

point_count

◆ SetPointCountRange() [1/2]

void ON_NurbsCurveFitParameters::SetPointCountRange	(	int	minimum_point_count,
		int	maximum_point_count
	)

Use SetPointCountRange() if you want the NURBS curve fit with the smallest separation having the point count in the specified range.

Parameters

minimum_point_count
maximum_point_count

◆ SetPointCountRange() [2/2]

void ON_NurbsCurveFitParameters::SetPointCountRange	(	int	minimum_point_count,
		int	maximum_point_count,
		double	tolerance
	)

Use SetPointCountRange() if you want the NURBS curve fit with the smallest separation having the point count in the specified range. This version of SetPointCountRange() lets you also specify a tolerance.

Parameters

minimum_point_count
maximum_point_count
tolerance	tolerance >= 0. If you are willing to accept any separation below a certain value, pass that value as tolerance. Otherwise pass 0.0.

◆ SetProgressReporter()

void ON_NurbsCurveFitParameters::SetProgressReporter ( class ON_ProgressReporter * progress_reporter )

◆ SetSampleCount()

void ON_NurbsCurveFitParameters::SetSampleCount ( int sample_count )

◆ SetSmoothingCoefficient()

void ON_NurbsCurveFitParameters::SetSmoothingCoefficient ( double smoothing_coefficient )

Specify a smoothing coefficient.

Parameters

smoothing_coefficient Valid values are in the range 0 <= smoothing_coefficient <= ON_NurbsCurveFitParameters::MaximumCustomSmoothingCoefficient. If smoothing_coefficient is not valid, then smoothing intensity is set to ON_NurbsCurveFitParameters::Smoothing::None.

◆ SetSmoothingIntensity()

void ON_NurbsCurveFitParameters::SetSmoothingIntensity ( ON_NurbsCurveFitParameters::Intensity smoothing_intensity )

Use one of the one of ON_NurbsCurveFitParameters::Intensity enum values to specify a smoothing coefficient. This method is provided to make it easier to provide an interface that lets a user select reasonable values for the smoothing penalty without having to understand the objective fuction calculation.

Parameters

smoothing_intensity One of ON_NurbsCurveFitParameters::Intensity enum values. If ON_NurbsCurveFitParameters::Intensity::Custom is passed in and a preexisting custom smoothing penalty has not been specified using SetSmoothingCoefficient(), then SmothingIntensity() is set to none. If you want to set a custom smoothing coefficient, use SetSmoothingCoefficient(smoothing_coefficient).

◆ SetSubDFriendly()

void ON_NurbsCurveFitParameters::SetSubDFriendly ( bool bSubDFriendly )

◆ SetTangentMatching()

void ON_NurbsCurveFitParameters::SetTangentMatching ( ON_NurbsCurveFitParameters::TangentMatch tangent_matching )

◆ SetTerminator()

void ON_NurbsCurveFitParameters::SetTerminator ( class ON_Terminator * terminator )

◆ SetUniformityCoefficient()

void ON_NurbsCurveFitParameters::SetUniformityCoefficient ( double uniformity_coefficient )

Specify a uniformity coefficient. Positive uniformity coefficients make the distances between control points more uniform. In general, use the smallest value that gives the desired result.

Parameters

uniformity_coefficient Valid values are in the range 0 <= uniformity_coefficient <= ON_NurbsCurveFitParameters::MaximumUniformityCoefficient. If uniformity_coefficient is not valid, then uniformity is set to ON_NurbsCurveFitParameters::Uniformity::None.

◆ SetUniformityIntensity()

void ON_NurbsCurveFitParameters::SetUniformityIntensity ( ON_NurbsCurveFitParameters::Intensity uniformity_intensity )

Use one of ON_NurbsCurveFitParameters::Intensity enum values to specify a uniformity coefficient. This method is provided to make it easier to provide an interface that lets a user select reasonable values for the uniformity coefficient without having to understand the optimization calculation. Positive uniformity coefficients make the distances between control points more uniform. In general, use the smallest value that gives the desired result.

Parameters

uniformity_intensity One of ON_NurbsCurveFitParameters::Intensity enum values. If ON_NurbsCurveFitParameters::Intensity::Custom is passed in and a preexisting custom uniformity penalty has not been specified using SetUniformityCoefficient(), then UniformityIntensity() is set to none. If you want to set a custom uniformity coefficient, use SetUniformityCoefficient(x).

◆ SmoothingCoefficient()

double ON_NurbsCurveFitParameters::SmoothingCoefficient ( ) const

Returns: The value of the smoothing penalty coefficient used in the objective function. 0 indicates no smoothing penalty. Values > 0 and <= ON_NurbsCurveFitParameters::MaximumCustomSmoothingCoefficient indicate a smoothing penalty will be applied. NaN indicates invalid settings and no smoothing penalty will be applied. Note that a smoothing penalty only applies when ther are 3 or more control points in the NURBS curve fit.

◆ SmoothingIntensity()

ON_NurbsCurveFitParameters::Intensity ON_NurbsCurveFitParameters::SmoothingIntensity ( ) const

The smoothing penalty in the objective function penalizes triplets of contiguous control points that are not colinear and equally spaced. Use SmoothingCoefficient() to get the numerical coefficient used in the objective function. Use SetSmoothingCoefficient() to set a custom smoothing coefficient.

Returns: The intensity of the smoothing penalty in the objective function.

◆ SubDFriendly()

bool ON_NurbsCurveFitParameters::SubDFriendly ( ) const

◆ TangentMatchFromInt()

static ON_NurbsCurveFitParameters::TangentMatch ON_NurbsCurveFitParameters::TangentMatchFromInt	(	int	tangent_match_as_int,
		ON_NurbsCurveFitParameters::TangentMatch	invalid_input_result
	)

static

Convert an integer value to the ON_NurbsCurveFitParameters::TangentMatch enum with the same value.

Parameters

tangent_match_as_int
invalid_input_result	If tangent_match_as_int does not match an TangentMatch enum value, then this value is returned.

Returns

◆ TangentMatching()

ON_NurbsCurveFitParameters::TangentMatch ON_NurbsCurveFitParameters::TangentMatching ( ) const

◆ TerminationRequested()

bool ON_NurbsCurveFitParameters::TerminationRequested ( ) const

◆ Terminator()

class ON_Terminator* ON_NurbsCurveFitParameters::Terminator ( ) const

◆ UniformityCoefficient()

double ON_NurbsCurveFitParameters::UniformityCoefficient ( ) const

Returns: The value of the uniformity penalty coefficient used in the objective function. 0 indicates no uniformity penalty. Values > 0 and <= ON_NurbsCurveFitParameters::MaximumCustomUniformityCoefficient indicate uniformity penalty will be applied. NaN indicates invalid settings and no uniformity penalty will be applied. Note that uniformity penalty only applies when there are 3 or more control points in the NURBS curve fit.

◆ UniformityIntensity()

ON_NurbsCurveFitParameters::Intensity ON_NurbsCurveFitParameters::UniformityIntensity ( ) const

The uniformity penalty in the objective function penalizes variation in the distances between control points. Use UniformityCoefficient() to get the numerical coefficient used in the objective function. Use SetUniformityCoefficient() to set a custom uniformity penalty coefficient.

Returns: The intensity of the uniformity penalty in the objective function.

◆ ValidInput()

static bool ON_NurbsCurveFitParameters::ValidInput	(	size_t	sample_point_count,
		unsigned	degree,
		unsigned	control_point_count,
		bool	bClosed,
		ON_Interval	curve_domain
	)

static

◆ VariablePointCount()

bool ON_NurbsCurveFitParameters::VariablePointCount ( ) const

Returns: Returns true if the best fit in a range of point counts should be returned.

Member Data Documentation

◆ ExtremeCurvatureBiasCoefficient

constexpr double ON_NurbsCurveFitParameters::ExtremeCurvatureBiasCoefficient = 10.0

staticconstexpr

Curvature bias coefficient that corresponds to ON_NurbsCurveFitParameters::Intensity::High.

◆ ExtremeSmoothingCoefficient

constexpr double ON_NurbsCurveFitParameters::ExtremeSmoothingCoefficient = 10.0

staticconstexpr

Smoothing coefficient that corresponds to ON_NurbsCurveFitParameters::Intensity::Extreme.

◆ ExtremeUniformityCoefficient

constexpr double ON_NurbsCurveFitParameters::ExtremeUniformityCoefficient = 10.0

staticconstexpr

Uniformity coefficient that corresponds to ON_NurbsCurveFitParameters::Intensity::High.

◆ HighCurvatureBiasCoefficient

constexpr double ON_NurbsCurveFitParameters::HighCurvatureBiasCoefficient = 1.0

staticconstexpr

Curvature bias coefficient that corresponds to ON_NurbsCurveFitParameters::Intensity::High.

◆ HighSmoothingCoefficient

constexpr double ON_NurbsCurveFitParameters::HighSmoothingCoefficient = 1.0

staticconstexpr

Smoothing coefficient that corresponds to ON_NurbsCurveFitParameters::Intensity::High.

◆ HighUniformityCoefficient

constexpr double ON_NurbsCurveFitParameters::HighUniformityCoefficient = 1.0

staticconstexpr

Uniformity coefficient that corresponds to ON_NurbsCurveFitParameters::Intensity::High.

◆ LowCurvatureBiasCoefficient

constexpr double ON_NurbsCurveFitParameters::LowCurvatureBiasCoefficient = 0.001

staticconstexpr

Curvature bias coefficient that corresponds to ON_NurbsCurveFitParameters::Intensity::Low.

◆ LowSmoothingCoefficient

constexpr double ON_NurbsCurveFitParameters::LowSmoothingCoefficient = 0.001

staticconstexpr

Smoothing coefficient that corresponds to ON_NurbsCurveFitParameters::Intensity::Low.

◆ LowUniformityCoefficient

constexpr double ON_NurbsCurveFitParameters::LowUniformityCoefficient = 0.001

staticconstexpr

<summary<coefficient> Uniformity coefficient that corresponds to ON_NurbsCurveFitParameters::Intensity::Low.

◆ MaximumCurvatureBiasCoefficient

constexpr double ON_NurbsCurveFitParameters::MaximumCurvatureBiasCoefficient = 10.0

staticconstexpr

Maximum permitted curvature bias coefficient.

◆ MaximumSmoothingCoefficient

constexpr double ON_NurbsCurveFitParameters::MaximumSmoothingCoefficient = 10.0

staticconstexpr

Maximum permitted smoothing coefficient.

◆ MaximumUniformityCoefficient

constexpr double ON_NurbsCurveFitParameters::MaximumUniformityCoefficient = 10.0

staticconstexpr

Maximum permitted uniformity coefficient.

◆ MediumCurvatureBiasCoefficient

constexpr double ON_NurbsCurveFitParameters::MediumCurvatureBiasCoefficient = 0.1

staticconstexpr

Curvature bias coefficient that corresponds to ON_NurbsCurveFitParameters::Intensity::Medium.

◆ MediumSmoothingCoefficient

constexpr double ON_NurbsCurveFitParameters::MediumSmoothingCoefficient = 0.1

staticconstexpr

Smoothing coefficient that corresponds to ON_NurbsCurveFitParameters::Intensity::Medium.

◆ MediumUniformityCoefficient

constexpr double ON_NurbsCurveFitParameters::MediumUniformityCoefficient = 0.1

staticconstexpr

Uniformity coefficient that corresponds to ON_NurbsCurveFitParameters::Intensity::Medium.

◆ ModerateCurvatureBiasCoefficient

constexpr double ON_NurbsCurveFitParameters::ModerateCurvatureBiasCoefficient = 0.01

staticconstexpr

Curvature bias coefficient that corresponds to ON_NurbsCurveFitParameters::Intensity::Moderate.

◆ ModerateSmoothingCoefficient

constexpr double ON_NurbsCurveFitParameters::ModerateSmoothingCoefficient = 0.01

staticconstexpr

Smoothing coefficient that corresponds to ON_NurbsCurveFitParameters::Intensity::Moderate.

◆ ModerateUniformityCoefficient

constexpr double ON_NurbsCurveFitParameters::ModerateUniformityCoefficient = 0.01

staticconstexpr

<summary<coefficient> Uniformity coefficient that corresponds to ON_NurbsCurveFitParameters::Intensity::Moderate.

Public Types

Public Member Functions

Static Public Member Functions

Static Public Attributes

Detailed Description

Member Enumeration Documentation

◆ anonymous enum

◆ Intensity

◆ KinkSplit

◆ TangentMatch

Constructor & Destructor Documentation

◆ ON_NurbsCurveFitParameters() [1/2]

◆ ~ON_NurbsCurveFitParameters()

◆ ON_NurbsCurveFitParameters() [2/2]

Member Function Documentation

◆ ApplyTangentMatchingAtKinks()

◆ ClampedControlPointCount()

◆ Closed()

◆ ConstrainedPointCount()

◆ CurvatureBiasCoefficient()

◆ CurvatureBiasIntensity()

◆ Degree()

◆ GetPointCountRange()

◆ Hash()

◆ IntensityFromInt()

◆ KinkAngleDegrees()

◆ KinkAngleRadians()

◆ KinkDefinition()

◆ KinkSplitFromInt()

◆ KinkSplitting()

◆ MaximumDegreeForPointCount()

◆ MinimumPointCountForDegree()

◆ operator=()

◆ OptimizeCurve()

◆ PeriodicControlPointCount()

◆ PointCount()

◆ PointCountRange()

◆ PointCountRangeMaximum()

◆ PointCountRangeMinimum()

◆ PointCountRangeTolerance()

◆ ProgressReporter()

◆ SampleCount()

◆ SetApplyTangentMatchingAtKinks()

◆ SetClosed()

◆ SetCurvatureBiasCoefficient()

◆ SetCurvatureBiasIntensity()

◆ SetDegree()

◆ SetKinkAngleDegrees()

◆ SetKinkAngleRadians()

◆ SetKinkSplitting()

◆ SetOptimizeCurve()

◆ SetPointCount()

◆ SetPointCountRange() [1/2]

◆ SetPointCountRange() [2/2]

◆ SetProgressReporter()

◆ SetSampleCount()

◆ SetSmoothingCoefficient()

◆ SetSmoothingIntensity()

◆ SetSubDFriendly()

◆ SetTangentMatching()

◆ SetTerminator()

◆ SetUniformityCoefficient()

◆ SetUniformityIntensity()

◆ SmoothingCoefficient()

◆ SmoothingIntensity()

◆ SubDFriendly()

◆ TangentMatchFromInt()

◆ TangentMatching()

◆ TerminationRequested()

◆ Terminator()

◆ UniformityCoefficient()

◆ UniformityIntensity()

◆ ValidInput()

◆ VariablePointCount()

Member Data Documentation

◆ ExtremeCurvatureBiasCoefficient

◆ ExtremeSmoothingCoefficient

◆ ExtremeUniformityCoefficient

◆ HighCurvatureBiasCoefficient

◆ HighSmoothingCoefficient