struct FBM

Structure

FBM

A generic fractal brownian motion noise generator, capable of overlaying multiple instances of procedural noise at increasing frequencies.

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Symbols

Initializers

init(amplitude:Double, frequency:Double, seed:Int = 0)

Creates an instance with the given amplitude, frequency, and random seed values. This initializer creates an instance of fractal noise with a single octave, and is equivalent to creating an instance of the underlying noise generator.

init(amplitude:Double, frequency:Double, octaves:Int, persistence:Double = 0.75, lacunarity:Double = 2, seed:Int = 0)

Creates an instance with the given number of octaves of noise. The given amplitude is the amplitude of the first octave of noise, and is multiplied by persistence for each successive octave. The given frequency is the frequency of the first octave of noise, and is multiplied by the lacunarity for each successive octave. The seed value is passed through to the first octave of noise, and is incremented for each successive octave.

Instance methods

func evaluate(_ x:Double, _ y:Double) -> Double

Evaluates the noise field at the given coordinate. For three-dimensional and higher noise fields, the z and w coordinates, if applicable, are set to zero.

func evaluate(_ x:Double, _ y:Double, _ z:Double) -> Double

Evaluates the noise field at the given coordinate. For two-dimensional noise fields, the z coordinate is ignored. For four-dimensional noise fields, the w coordinate is set to zero.

func evaluate(_ x:Double, _ y:Double, _ z:Double, _ w:Double) -> Double

Evaluates the noise field at the given coordinate. For three-dimensional and lower noise fields, the z and w coordinates are ignored, if necessary. No existing noise generator in the library currently supports true four-dimensional evaluation.

func sample_area(width:Int, height:Int) -> [(Double, Double, Double)]

Evaluates the noise field over the given area, starting from the origin, and extending over the first quadrant, taking unit steps in both directions. Although the x and y coordinates are returned, the output vector is guaranteed to be in row-major order.

func sample_area_saturated_to_u8(width:Int, height:Int, offset:Double = 0.5) -> [UInt8]

Evaluates the noise field over the given area, starting from the origin, and extending over the first quadrant, storing the values in a row-major array of samples. The samples are clamped, but not scaled, to the range 0 ... 255.

func sample_volume(width:Int, height:Int, depth:Int) -> [(Double, Double, Double, Double)]

Evaluates the noise field over the given volume, starting from the origin, and extending over the first octant, taking unit steps in all three directions. Although the x, y, and z coordinates are returned, the output vector is guaranteed to be in xy-plane-major, and then row-major order.

func sample_volume_saturated_to_u8(width:Int, height:Int, depth:Int, offset:Double = 0.5) -> [UInt8]

Evaluates the noise field over the given volume, starting from the origin, and extending over the first octant, storing the values in a xy-plane-major, and then row-major order array of samples. The samples are clamped, but not scaled, to the range 0 ... 255.

Relationships

Generic constraints

Generator:Noise

Conforms to

Noise