Description

Geometric object representing a NURBS spline.

#include <ChLineNurbs.h>

Inheritance diagram for chrono::geometry::ChLineNurbs:

Collaboration diagram for chrono::geometry::ChLineNurbs:

Public Member Functions
	ChLineNurbs ()
	Constructor. By default, a segment (order = 1, two points on X axis, at -1, +1)

	ChLineNurbs (int morder, std::vector< ChVector<> > &mpoints, ChVectorDynamic<> mknots=0, ChVectorDynamic<> weights=0)
	Constructor from a given array of control points. More...

	ChLineNurbs (const ChLineNurbs &source)

virtual ChLineNurbs *	Clone () const override
	"Virtual" copy constructor (covariant return type).

virtual int	Get_complexity () const override
	Tell the complexity.

virtual void	Evaluate (ChVector<> &pos, const double parU) const override
	Evaluates a point on the line, given parametric coordinate U. More...

virtual void	Derive (ChVector<> &dir, const double parU) const override
	Evaluates a tangent versor, given parametric coordinate. More...

double	ComputeUfromKnotU (const double u) const
	When using Evaluate() etc. More...

double	ComputeKnotUfromU (const double U) const
	When using Evaluate() etc. More...

std::vector< ChVector<> > &	Points ()
	Access the points.

ChVectorDynamic &	Weights ()
	Access the weights.

ChVectorDynamic &	Knots ()
	Access the knots.

int	GetOrder ()
	Get the order of spline.

virtual void	SetupData (int morder, std::vector< ChVector<> > &mpoints, ChVectorDynamic<> mknots=0, ChVectorDynamic<> weights=0)
	Initial easy setup from a given array of control points. More...

virtual void	ArchiveOUT (ChArchiveOut &marchive) override
	Method to allow serialization of transient data to archives.

virtual void	ArchiveIN (ChArchiveIn &marchive) override
	Method to allow de-serialization of transient data from archives.

Public Member Functions inherited from chrono::geometry::ChLine
	ChLine (const ChLine &source)

virtual GeometryType	GetClassType () const override
	"Virtual" copy constructor (covariant return type). More...

virtual bool	Get_closed () const
	Tell if the curve is closed.

virtual void	Set_closed (bool mc)

virtual void	Set_complexity (int mc)

virtual int	GetManifoldDimension () const override
	This is a line.

bool	FindNearestLinePoint (ChVector<> &point, double &resU, double approxU, double tol) const
	Find the parameter resU for the nearest point on curve to "point".

virtual double	Length (int sampling) const
	Returns curve length. Typical sampling 1..5 (1 already gives correct result with degree1 curves)

virtual ChVector	GetEndA () const
	Return the start point of the line. More...

virtual ChVector	GetEndB () const
	Return the end point of the line. More...

double	CurveCurveDist (ChLine *compline, int samples) const
	Returns adimensional information on "how much" this curve is similar to another in its overall shape (does not matter parametrization or start point). More...

double	CurveSegmentDist (ChLine *complinesegm, int samples) const
	Same as before, but returns "how near" is complinesegm to whatever segment of this line (does not matter the percentual of line). More...

double	CurveCurveDistMax (ChLine *compline, int samples) const
	Same as above, but instead of making average of the distances, these functions return the maximum of the distances...

double	CurveSegmentDistMax (ChLine *complinesegm, int samples) const

virtual bool	DrawPostscript (ChFile_ps *mfle, int markpoints, int bezier_interpolate)
	Draw into the current graph viewport of a ChFile_ps file.

Public Member Functions inherited from chrono::geometry::ChGeometry
	ChGeometry (const ChGeometry &source)

virtual void	GetBoundingBox (double &xmin, double &xmax, double &ymin, double &ymax, double &zmin, double &zmax, ChMatrix33<> *Rot=nullptr) const
	Compute bounding box. More...

virtual void	InflateBoundingBox (double &xmin, double &xmax, double &ymin, double &ymax, double &zmin, double &zmax, ChMatrix33<> *Rot=NULL) const
	Enlarge a previous existing bounding box. More...

virtual double	Size () const
	Returns the radius of the sphere which can enclose the geometry.

virtual ChVector	Baricenter () const
	Compute center of mass It should be overridden by inherited classes.

virtual void	CovarianceMatrix (ChMatrix33<> &C) const
	Compute the 3x3 covariance matrix (only the diagonal and upper part) It should be overridden by inherited classes.

virtual void	Update ()
	Generic update of internal data. More...

Public Attributes
std::vector< ChVector<> >	points

ChVectorDynamic	weights

ChVectorDynamic	knots

int	p

Additional Inherited Members
Public Types inherited from chrono::geometry::ChGeometry
enum	GeometryType { NONE, SPHERE, BOX, CYLINDER, TRIANGLE, CAPSULE, CONE, LINE, LINE_ARC, LINE_BEZIER, LINE_CAM, LINE_PATH, LINE_POLY, LINE_SEGMENT, ROUNDED_BOX, ROUNDED_CYLINDER, ROUNDED_CONE, TRIANGLEMESH, TRIANGLEMESH_CONNECTED, TRIANGLEMESH_SOUP }
	Enumeration of geometric objects.

Protected Attributes inherited from chrono::geometry::ChLine
bool	closed

int	complexityU

Constructor & Destructor Documentation

◆ ChLineNurbs()

chrono::geometry::ChLineNurbs::ChLineNurbs	(	int	morder,
		std::vector< ChVector<> > &	mpoints,
		ChVectorDynamic<> *	mknots = `0`,
		ChVectorDynamic<> *	weights = `0`
	)

Constructor from a given array of control points.

Input data is copied. If the knots are not provided, a uniformly spaced knot vector is made. If the weights are not provided, a constant weight vector is made.

Parameters

morder	order p: 1= linear, 2=quadratic, etc.
mpoints	control points, size n. Required: at least n >= p+1
mknots	knots, size k. Required k=n+p+1. If not provided, initialized to uniform.
weights	weights, size w. Required w=n. If not provided, all weights as 1.

Member Function Documentation

◆ ComputeKnotUfromU()

double chrono::geometry::ChLineNurbs::ComputeKnotUfromU ( const double U ) const

inline

When using Evaluate() etc.

you need U parameter to be in 0..1 range, but knot range is not necessarily in 0..1. So you can convert U->u, where u is in knot range, calling this:

◆ ComputeUfromKnotU()

double chrono::geometry::ChLineNurbs::ComputeUfromKnotU ( const double u ) const

inline

When using Evaluate() etc.

you need U parameter to be in 0..1 range, but knot range is not necessarily in 0..1. So you can convert u->U, where u is in knot range, calling this:

◆ Derive()

void chrono::geometry::ChLineNurbs::Derive	(	ChVector<> &	dir,
		const double	parU
	)		const

overridevirtual

Evaluates a tangent versor, given parametric coordinate.

Parameter U always work in 0..1 range. Computed value goes into the 'pos' reference.

Reimplemented from chrono::geometry::ChLine.

◆ Evaluate()

void chrono::geometry::ChLineNurbs::Evaluate	(	ChVector<> &	pos,
		const double	parU
	)		const

overridevirtual

Evaluates a point on the line, given parametric coordinate U.

Parameter U always work in 0..1 range, even if knots are not in 0..1 range. So if you want to use u' in knot range, use ComputeUfromKnotU(). Computed value goes into the 'pos' reference. It must be implemented by inherited classes.

Implements chrono::geometry::ChLine.

◆ SetupData()

void chrono::geometry::ChLineNurbs::SetupData	(	int	morder,
		std::vector< ChVector<> > &	mpoints,
		ChVectorDynamic<> *	mknots = `0`,
		ChVectorDynamic<> *	weights = `0`
	)

virtual

Initial easy setup from a given array of control points.