A Sampler class for sampling rays uniformely from a cone. More...

#include <UniformBeamSampler.h>

Inheritance diagram for UniformBeamSampler:

Collaboration diagram for UniformBeamSampler:

Public Member Functions
	UniformBeamSampler (const unsigned int &nbRays=0, const decimal &alpha=(decimal) M_PI, const vec3 &directivity=vec3(0, 0, 1))
	Constructors. More...

	UniformBeamSampler (const UniformBeamSampler &other)

	UniformBeamSampler (UniformBeamSampler *sampler)

virtual Sampler *	Clone ()
	Clone a sample. More...

virtual	~UniformBeamSampler ()
	Destructor. More...

void	next_slice ()

virtual vec3	getSample ()
	Return the sample. More...

virtual bool	isAcceptableSample (vec3 v)
	Return true for an acceptable sample. More...

virtual void	init ()
	Initialize the sample. More...

unsigned int	getRealNbRays () const

void	setOpeningAngle (const decimal &Alpha)

decimal	getOpeningAngle ()

void	setDirectivity (const vec3 &Directivity)

vec3	getDirectivity ()

virtual unsigned int	computeDiffractionNbr (const decimal &thetaCalcul)
	Return the number of rays to launch after a diffraction event. More...

Public Member Functions inherited from Sampler
	Sampler (const unsigned int &nbRays=0, const decimal &Theta=(decimal) M_PIDIV2, const decimal &Phi=(decimal) M_2PI)
	Default constructor. More...

	Sampler (const Sampler &other)
	Copy constructors. More...

	Sampler (Sampler *sampler)

virtual	~Sampler ()
	Destructor. More...

virtual unsigned int	getNbRays () const
	Get/Set the number of rays to launch. More...

virtual void	setNbRays (const unsigned int &nbRays)

decimal	getTheta () const
	Get/Set the polar angle. More...

void	setTheta (const decimal &Theta)

decimal	getPhi () const
	Get/Set the equatorial polar angle. More...

void	setPhi (const decimal &Phi)

Private Member Functions
void	find_number_of_slices ()

Private Attributes
unsigned int	_real_nb_rays
	Real number of rays launched. More...

unsigned int	_slices
	Number of slices. More...

unsigned int	_slice_rays
	Number of remaining rays to launch for the current slice. More...

decimal	_radius
	radius of the current slice More...

decimal	_alpha
	Opening angle of the cone. More...

vec3	_directivity
	Directivity of the beam. More...

unsigned int	_i

unsigned int	_j
	Current indices ( respectively slice index and sample index of the current slice) More...

Repere	_repere
	Repere used to rotate the beam in direction of the directivity. More...

Additional Inherited Members
Protected Attributes inherited from Sampler
unsigned int	_nb_rays
	Number of rays to launch. More...

decimal	_theta
	Global polar angle. More...

decimal	_phi
	Global equatorial angle. More...

Detailed Description

A Sampler class for sampling rays uniformely from a cone.

Principle : Sample points on the spherical cap resulting from the intersection between the unit sphere and the cone of axis z-axis and opening angle alpha. Then rotate the samples so that the axis of the cone points in the direction of the directivity

The cap is divided into horizontal slices on which points are sampled. The angle between consecutive slices is phi. The angle between consecutive samples on the same slice is theta. Theta is computed so that the arc length between neighboring samples on the same slice is equal to the arc length between neihboring slices (hence the uniformity of the samples) This means that the phi angle directly controls the number of slices and indirectly controls the number samples on each one of them. This gives us a nice uniform distribution of the samples but it prevents us from chosing exactly how many samples are generated.

The phi angle (and therefore the number of slices) is choosen so that the real number of samples is at least equal to the desired number of rays (nbRays)

Note : The first sample is always (0,0,1) Therefore, if we launch at least one ray, the first ray is always collinear with the directivity of the source

Ref : This approach is refered as Rusin's discoball Some more details on evenly distributed points on a sphere : http://web.archive.org/web/20120107030109/http://cgafaq.info/wiki/Evenly_distributed_points_on_sphere Comparison with the "golden sector" and the "Saff & Kuijlaar" approaches : https://bendwavy.org/pack/pack.htm

Definition at line 64 of file UniformBeamSampler.h.

Constructor & Destructor Documentation

◆ UniformBeamSampler() [1/3]

UniformBeamSampler::UniformBeamSampler	(	const unsigned int &	nbRays = `0`,
		const decimal &	alpha = `(decimal)M_PI`,
		const vec3 &	directivity = `vec3(0, 0, 1)`
	)

inline

Constructors.

Definition at line 68 of file UniformBeamSampler.h.

◆ UniformBeamSampler() [2/3]

UniformBeamSampler::UniformBeamSampler ( const UniformBeamSampler & other )

inline

Definition at line 77 of file UniformBeamSampler.h.

◆ UniformBeamSampler() [3/3]

UniformBeamSampler::UniformBeamSampler ( UniformBeamSampler * sampler )

inline

Definition at line 91 of file UniformBeamSampler.h.

◆ ~UniformBeamSampler()

virtual UniformBeamSampler::~UniformBeamSampler ( )

inlinevirtual

Destructor.

Definition at line 111 of file UniformBeamSampler.h.

Member Function Documentation

◆ Clone()

virtual Sampler* UniformBeamSampler::Clone ( )

inlinevirtual

Clone a sample.

Reimplemented from Sampler.

Definition at line 105 of file UniformBeamSampler.h.

◆ computeDiffractionNbr()

virtual unsigned int UniformBeamSampler::computeDiffractionNbr ( const decimal & theta )

inlinevirtual

Return the number of rays to launch after a diffraction event.

Reimplemented from Sampler.

Definition at line 207 of file UniformBeamSampler.h.

◆ find_number_of_slices()

void UniformBeamSampler::find_number_of_slices ( )

inlineprivate

Definition at line 215 of file UniformBeamSampler.h.

◆ getDirectivity()

vec3 UniformBeamSampler::getDirectivity ( )

inline

Definition at line 202 of file UniformBeamSampler.h.

◆ getOpeningAngle()

decimal UniformBeamSampler::getOpeningAngle ( )

inline

Definition at line 189 of file UniformBeamSampler.h.

◆ getRealNbRays()

unsigned int UniformBeamSampler::getRealNbRays ( ) const

inline

Definition at line 176 of file UniformBeamSampler.h.

◆ getSample()

virtual vec3 UniformBeamSampler::getSample ( )

inlinevirtual

Return the sample.

Reimplemented from Sampler.

Definition at line 125 of file UniformBeamSampler.h.

◆ init()

virtual void UniformBeamSampler::init ( )

inlinevirtual

Initialize the sample.

Reimplemented from Sampler.

Definition at line 157 of file UniformBeamSampler.h.

◆ isAcceptableSample()

virtual bool UniformBeamSampler::isAcceptableSample ( vec3 v )

inlinevirtual

Return true for an acceptable sample.

Reimplemented from Sampler.

Definition at line 152 of file UniformBeamSampler.h.

◆ next_slice()

void UniformBeamSampler::next_slice ( )

inline

Definition at line 114 of file UniformBeamSampler.h.

◆ setDirectivity()

void UniformBeamSampler::setDirectivity ( const vec3 & Directivity )

inline

Definition at line 195 of file UniformBeamSampler.h.

◆ setOpeningAngle()

void UniformBeamSampler::setOpeningAngle ( const decimal & Alpha )

inline

Definition at line 182 of file UniformBeamSampler.h.

Member Data Documentation

◆ _alpha

decimal UniformBeamSampler::_alpha

private

Opening angle of the cone.

Definition at line 251 of file UniformBeamSampler.h.

◆ _directivity

vec3 UniformBeamSampler::_directivity

private

Directivity of the beam.

Definition at line 252 of file UniformBeamSampler.h.

◆ _i

unsigned int UniformBeamSampler::_i

private

Definition at line 253 of file UniformBeamSampler.h.

◆ _j

unsigned int UniformBeamSampler::_j

private

Current indices ( respectively slice index and sample index of the current slice)

Definition at line 254 of file UniformBeamSampler.h.

◆ _radius

decimal UniformBeamSampler::_radius

private

radius of the current slice

Definition at line 250 of file UniformBeamSampler.h.

◆ _real_nb_rays

unsigned int UniformBeamSampler::_real_nb_rays

private

Real number of rays launched.

Definition at line 247 of file UniformBeamSampler.h.

◆ _repere

Repere UniformBeamSampler::_repere

private

Repere used to rotate the beam in direction of the directivity.

Definition at line 255 of file UniformBeamSampler.h.

◆ _slice_rays

unsigned int UniformBeamSampler::_slice_rays

private

Number of remaining rays to launch for the current slice.

Definition at line 249 of file UniformBeamSampler.h.

◆ _slices

unsigned int UniformBeamSampler::_slices

private

Number of slices.

Definition at line 248 of file UniformBeamSampler.h.

The documentation for this class was generated from the following file:

/home/docs/checkouts/readthedocs.org/user_builds/code-tympan-fbessou/checkouts/latest/Tympan/geometric_methods/AcousticRaytracer/Geometry/UniformBeamSampler.h

Public Member Functions

Private Member Functions

Private Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ UniformBeamSampler() [1/3]

◆ UniformBeamSampler() [2/3]

◆ UniformBeamSampler() [3/3]

◆ ~UniformBeamSampler()

Member Function Documentation

◆ Clone()

◆ computeDiffractionNbr()

◆ find_number_of_slices()

◆ getDirectivity()

◆ getOpeningAngle()

◆ getRealNbRays()

◆ getSample()

◆ init()

◆ isAcceptableSample()

◆ next_slice()

◆ setDirectivity()

◆ setOpeningAngle()

Member Data Documentation

◆ _alpha

◆ _directivity

◆ _i

◆ _j

◆ _radius

◆ _real_nb_rays

◆ _repere

◆ _slice_rays

◆ _slices