PerlinSDF< T > Class Template Reference

Ken Perlins gradient noise function. More...

#include <EBGeometry_AnalyticDistanceFunctions.hpp>

Inheritance diagram for PerlinSDF< T >:

Collaboration diagram for PerlinSDF< T >:

Public Member Functions
	PerlinSDF (const T a_noiseAmplitude, const Vec3T< T > a_noiseFrequency, const T a_noisePersistence, const unsigned int a_noiseOctaves) noexcept
	Full constructor.
virtual	~PerlinSDF () noexcept
	Destructor (does nothing)
virtual T	signedDistance (const Vec3T< T > &a_point) const noexcept override
	Signed distance function. Generates a distance on [0,curAmplitude].
template<class URNG >
void	shuffle (URNG &g) noexcept
	Shuffle the permutation with the input RNG.
std::array< int, 512 > &	getPermutationTable () noexcept
	Get the internal permutation table.
Public Member Functions inherited from SignedDistanceFunction< T >
	SignedDistanceFunction ()=default
	Disallowed, use the full constructor.
virtual	~SignedDistanceFunction ()=default
	Destructor (does nothing)
virtual T	value (const Vec3T< T > &a_point) const noexcept override final
	Implementation of ImplicitFunction::value.
virtual Vec3T< T >	normal (const Vec3T< T > &a_point, const T &a_delta) const noexcept
	Signed distance normal vector.
Public Member Functions inherited from ImplicitFunction< T >
	ImplicitFunction ()=default
	Disallowed, use the full constructor.
virtual	~ImplicitFunction ()=default
	Destructor (does nothing)
T	operator() (const Vec3T< T > &a_point) const noexcept
	Alternative signature for the value function.
template<class BV >
BV	approximateBoundingVolumeOctree (const Vec3T< T > &a_initialLowCorner, const Vec3T< T > &a_initialHighCorner, const unsigned int a_maxTreeDepth, const T &a_safety=0.0) const noexcept
	Compute an approximation to the bounding volume for the implicit surface, using octrees.

Protected Member Functions
virtual T	lerp (const T t, const T a, const T b) const noexcept
	Ken Perlin's lerp function.
virtual T	fade (const T t) const noexcept
	Ken Perlin's fade function.
T	grad (const int hash, const T x, const T y, const T z) const noexcept
	Ken Perlins grad function.
T	noise (const Vec3T< T > &a_point) const noexcept
	Octave noise function.

Protected Attributes
Vec3T< T >	m_noiseFrequency
	Noise frequency.
T	m_noiseAmplitude
	Noise amplitude.
T	m_noisePersistence
	Noise persistence.
std::array< T, 512 >	m_permutationTable
	Permutation table.
unsigned int	m_noiseOctaves
	Number of noise octaves.

Detailed Description

template<class T>
class PerlinSDF< T >

Ken Perlins gradient noise function.

Constructor & Destructor Documentation

PerlinSDF()

template<class T >

PerlinSDF< T >::PerlinSDF ( const T  a_noiseAmplitude, const Vec3T< T >  a_noiseFrequency, const T  a_noisePersistence, const unsigned int  a_noiseOctaves  )

inlinenoexcept

Full constructor.

Parameters

[in]	a_noiseAmplitude	Noise amplitude
[in]	a_noiseFrequency	Spatial noise frequency along the three Cartesian axes
[in]	a_noisePersistence	Noise amplitude drop-off and frequency increase for octave noise. Should be < 1
[in]	a_noiseOctaves	Number of octaves. Should be > 0

Member Function Documentation

fade()

template<class T >

virtual T PerlinSDF< T >::fade ( const T  t ) const

inlineprotectedvirtualnoexcept

Ken Perlin's fade function.

Parameters

[in]

t

Input parameter

getPermutationTable()

template<class T >

std::array< int, 512 > & PerlinSDF< T >::getPermutationTable ( )

inlinenoexcept

Get the internal permutation table.

Returns

m_permutationTable.

grad()

template<class T >

T PerlinSDF< T >::grad ( const int  hash, const T  x, const T  y, const T  z  ) const

inlineprotectednoexcept

Ken Perlins grad function.

Parameters

[in]	hash	Input parameter
[in]	x	Input parameter
[in]	y	Input parameter
[in]	z	Input parameter

lerp()

template<class T >

virtual T PerlinSDF< T >::lerp ( const T  t, const T  a, const T  b  ) const

inlineprotectedvirtualnoexcept

Ken Perlin's lerp function.

Parameters

[in]	t	Input parameter
[in]	a	Input parameter
[in]	b	Input parameter

noise()

template<class T >

T PerlinSDF< T >::noise ( const Vec3T< T > &  a_point ) const

inlineprotectednoexcept

Octave noise function.

Parameters

[in]

a_point

Input point

shuffle()

template<class T >

template<class URNG >

void PerlinSDF< T >::shuffle ( URNG &  g )

inlinenoexcept

Shuffle the permutation with the input RNG.

URNG should be a uniform random number generator, e.g.

Parameters

[in]

g

Uniform random number generator (e.g., std::mt19937)

Note

When using parallel calculations it is exceptionally important that the input RNG is the same across all threads/ranks. Otherwise, the user must manually ensure that the permutation table is the same. Failure to do so implies that each thread/rank generates it's own gradient noise and there is correspondingly no single geometry.

signedDistance()

template<class T >

virtual T PerlinSDF< T >::signedDistance ( const Vec3T< T > &  a_point ) const

inlineoverridevirtualnoexcept

Signed distance function. Generates a distance on [0,curAmplitude].

Parameters

[in]

a_point

Input point

Implements SignedDistanceFunction< T >.

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

• /home/runner/work/EBGeometry/EBGeometry/Source/EBGeometry_AnalyticDistanceFunctions.hpp