SimplexTurbulence2 Class Reference

Fractal Brownian motion from a simplex noise function. More...

#include <turbulence.h>

Inheritance diagram for SimplexTurbulence2:

Public Member Functions
	SimplexTurbulence2 ()
	Unit turbulence.
	SimplexTurbulence2 (const double &, const double &, const double &, const double &=0.5, const double &=0.5, int=8, const Vector2 &=Vector::Null)
	Create a scaled turbulence.
	~SimplexTurbulence2 ()
	Empty.
double	Value (const Vector2 &) const
	Compute the simplex noise at a given point.
double	GetAlpha () const
	Return the amplitude dampening coefficient.
double	GetLambda () const
	Return the wavelength dampening coefficient.
double	GetOctaves () const
	Number of octaves.
double	K () const
	Return the global Lipschitz constant.
double	Maximum () const
	Return the maximum of the turbulence.
virtual ScalarField2	Sample (const Array2 &) const
	Create a discrete scalar field by sampling a given domain.

Protected Member Functions
double	UnitAt (const Vector2 &) const
	Compute the turbulence value at a given point.
Protected Member Functions inherited from SimplexNoise2
	SimplexNoise2 ()
	Empty.
	~SimplexNoise2 ()
	Empty.
double	K () const
	Return the global Lipschitz constant of the noise.
Protected Member Functions inherited from AnalyticScalarField2
Matrix	Local (const Vector2 &) const
	Compute the local neighborhood in the one-ring aroung a point.
	AnalyticScalarField2 (bool=true)
	Constructor.
virtual Vector2	Gradient (const Vector2 &) const
	Compute the gradient of the field.
virtual Matrix2	Hessian (const Vector2 &) const
	Compute the hessian at a given point.
bool	Inside (const double &) const
	Check if the value is considered as inside or outside.
void	Curvature (const Vector2 &, double &, double &) const
	Compute the gaussian and mean curvatures.
virtual Box2	GetBox () const
	Return the bounding box.

Protected Attributes
double	alpha = 0.5
	Amplitude attenuation coefficient.
double	lambda = 0.5
	Wavelength amplification coefficient.
int	octaves = 8
	Number of octaves.
Vector2	t = Vector2::Null
	Translation.
double	v0 = 0.0
	Base value.
double	a0 = 1.0
	Base amplitude.
double	l0 = 1.0
	Wavelength.
Protected Attributes inherited from AnalyticScalarField2
bool	sign = true
	Sign convention, used for normal computation.
Box2	box = Box2::Infinity
	Domain, set as infinite for base class.

Static Protected Attributes
static const Matrix2	R2 = Matrix2::Rotation(4.0 * Math::Pi / 19.0)
	Random incremental rotation in the plane.
Static Protected Attributes inherited from SimplexNoise2
static const Vector2	grad2 [8]
	Array of gradients.
static const int	perm [512]
	Permutation table, 256 entries duplicated once to avoid modulo computations.
static const double	G2 = (3.0 - sqrt(3.0)) / 6.0
	Unskew factors for planar case.
Static Protected Attributes inherited from AnalyticScalarField2
static const double	epsilon = 1e-6
	\epsilon; value for partial derivatives

Friends
std::ostream &	operator<< (std::ostream &s, const SimplexTurbulence2 &noise)
	Overloaded.

Detailed Description

Fractal Brownian motion from a simplex noise function.

A turbulence field is characterized by the number of octaves, the attenuation of the amplitude of the noise summed at every step, and by the amplification of the wavelength.

Constructor & Destructor Documentation

SimplexTurbulence2()

SimplexTurbulence2::SimplexTurbulence2 ( const double & v, const double & a, const double & l, const double & alpha = 0.5, const double & lambda = 0.5, int octaves = 8, const Vector2 & t = Vector::Null )

explicit

Create a scaled turbulence.

Parameters

v,a,l	Base value, amplitude and wavelength.
alpha	Amplitude attenuation factor (~0.5, should be less than 1.0).
lambda	Wavelength attenuation factor (~0.5, should be less than 1.0).
octaves	Number of octaves.
t	Translation offset.

Member Function Documentation

K()

double SimplexTurbulence2::K

(

)

const

Return the global Lipschitz constant.

See also

Noise::K()

Sample()

ScalarField2 AnalyticScalarField2::Sample ( const Array2 & a ) const

virtual

Create a discrete scalar field by sampling a given domain.

Parameters

a

Domain.

Reimplemented from AnalyticScalarField2.

UnitAt()

double SimplexTurbulence2::UnitAt ( const Vector2 & p ) const

protected

Compute the turbulence value at a given point.

Sums a series of scaled noise functions.

Parameters

p

Point.

Value()

double SimplexTurbulence2::Value ( const Vector2 & p ) const

virtual

Compute the simplex noise at a given point.

Parameters

p

Point.

Reimplemented from SimplexNoise2.

Friends And Related Symbol Documentation

operator<<

std::ostream & operator<< ( std::ostream & s, const SimplexTurbulence2 & noise )

friend

Overloaded.

Parameters

s	Stream.
noise	The noise.