Description

Geometric object representing a NURBS spline.

#include <ChLineNurbs.h>

Inheritance diagram for chrono::ChLineNurbs:

Collaboration diagram for chrono::ChLineNurbs:

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

	ChLineNurbs (int order, const std::vector< ChVector3d > &points, const ChVectorDynamic<> knots=nullptr, const ChVectorDynamic<> weights=nullptr)
	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	GetComplexity () const override
	Get the complexity.

virtual ChVector3d	Evaluate (double U) const override
	Return a point on the line, given parametric coordinate U (in [0,1]).

virtual ChVector3d	GetTangent (double parU) const override
	Return the tangent unit vector at the parametric coordinate U (in [0,1]).

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

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

std::vector< ChVector3d > &	Points ()
	Access the points.

ChVectorDynamic &	Weights ()
	Access the weights.

ChVectorDynamic &	Knots ()
	Access the knots.

int	GetOrder ()
	Get the order of spline.

virtual void	Setup (int order, const std::vector< ChVector3d > &points, const ChVectorDynamic<> knots=nullptr, const ChVectorDynamic<> weights=nullptr)
	Initial easy setup from a given array of control points. More...

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

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

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

virtual Type	GetType () const override
	"Virtual" copy constructor (covariant return type). More...

virtual bool	IsClosed () const
	Get if the curve is closed.

virtual void	SetClosed (bool mc)

virtual void	SetComplexity (int mc)

virtual int	GetManifoldDimension () const override
	Return dimensionality of this object. More...

bool	FindNearestLinePoint (const ChVector3d &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 ChVector3d	GetEndA () const
	Return the start point of the line. More...

virtual ChVector3d	GetEndB () const
	Return the end point of the line. More...

double	CurveCurveDist (const ChLine *compline, int samples) const
	Return adimensional information on "how much" this curve is similar to another in its overall shape. More...

double	CurveSegmentDist (const 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 (const 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 (const ChLine *complinesegm, int samples) const

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

virtual ChAABB	GetBoundingBox () const
	Compute bounding box along the directions of the shape definition frame. More...

void	InflateBoundingBox (ChAABB &bbox) const
	Enlarge the given existing bounding box with the bounding box of this object.

virtual double	GetBoundingSphereRadius () const
	Returns the radius of a bounding sphere for this geometry. More...

virtual ChVector3d	Barycenter () const
	Compute center of mass.

virtual void	Update ()
	Generic update of internal data.

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

Protected Attributes inherited from chrono::ChLine
bool	closed

int	complexityU

Constructor & Destructor Documentation

◆ ChLineNurbs()

chrono::ChLineNurbs::ChLineNurbs	(	int	order,
		const std::vector< ChVector3d > &	points,
		const ChVectorDynamic<> *	knots = `nullptr`,
		const ChVectorDynamic<> *	weights = `nullptr`
	)

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

order	order p: 1= linear, 2=quadratic, etc.
points	control points, size n. Required: at least n >= p+1
knots	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::ChLineNurbs::ComputeKnotUfromU ( double U ) const

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, by calling this.

◆ ComputeUfromKnotU()

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

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, by calling this.

◆ Setup()

void chrono::ChLineNurbs::Setup	(	int	order,
		const std::vector< ChVector3d > &	points,
		const ChVectorDynamic<> *	knots = `nullptr`,
		const ChVectorDynamic<> *	weights = `nullptr`
	)

virtual

Initial easy setup from a given array of control points.