ExprUtils

Synopsis

Various functions useful for expressions. Most noise functions have been taken from the Walt Disney Animation Studio SeExpr library.

Functions

def boxstep (x,a)
def linearstep (x,a,b)
def smoothstep (x,a,b)
def gaussstep (x,a,b)
def remap (x,source,range,falloff,interp)
def mix (x,y,alpha)
def hash (args)
def noise (x)
def noise (p)
def noise (p)
def noise (p)
def snoise (p)
def vnoise (p)
def cnoise (p)
def snoise4 (p)
def vnoise4 (p)
def cnoise4 (p)
def turbulence (p[,ocaves=6, lacunarity=2, gain=0.5])
def vturbulence (p[,ocaves=6, lacunarity=2, gain=0.5])
def cturbulence (p[,ocaves=6, lacunarity=2, gain=0.5])
def fbm (p[,ocaves=6, lacunarity=2, gain=0.5])
def vfbm (p[,ocaves=6, lacunarity=2, gain=0.5])
def fbm4 (p[,ocaves=6, lacunarity=2, gain=0.5])
def vfbm4 (p[,ocaves=6, lacunarity=2, gain=0.5])
def cfbm (p[,ocaves=6, lacunarity=2, gain=0.5])
def cfbm4 (p[,ocaves=6, lacunarity=2, gain=0.5])
def cellnoise (p)
def ccellnoise (p)
def pnoise (p, period)

Member functions description

NatronEngine.ExprUtils.boxstep(x, a)

Parameters

x – float
a – float

Return type

float

if x < a then 0 otherwise 1

NatronEngine.ExprUtils.linearstep(x, a, b)

Parameters

x – float
a – float
b – float

Return type

float

Transitions linearly when a < x < b

NatronEngine.ExprUtils.boxstep(x, a, b)

Parameters

x – float
a – float
b – float

Return type

float

Transitions smoothly (cubic) when a < x < b

NatronEngine.ExprUtils.gaussstep(x, a, b)

Parameters

x – float
a – float
b – float

Return type

float

Transitions smoothly (exponentially) when a < x < b

NatronEngine.ExprUtils.remap(x, source, range, falloff, interp)

Parameters

x – float
source – float
range – float
falloff – float
interp – float

Return type

float

General remapping function. When x is within +/- range of source, the result is 1. The result falls to 0 beyond that range over falloff distance. The falloff shape is controlled by interp: linear = 0 smooth = 1 gaussian = 2

NatronEngine.ExprUtils.mix(x, y, alpha)

Parameters

x – float
y – float
alpha – float

Return type

float

Linear interpolation of a and b according to alpha

NatronEngine.ExprUtils.hash(args)

Parameters: args – Sequence
Return type: float

Like random, but with no internal seeds. Any number of seeds may be given and the result will be a random function based on all the seeds.

NatronEngine.ExprUtils.noise(x)

Parameters: x – float
Return type: float

Original perlin noise at location (C2 interpolant)

NatronEngine.ExprUtils.noise(p)

Parameters: p – Double2DTuple
Return type: float

Original perlin noise at location (C2 interpolant)

NatronEngine.ExprUtils.noise(p)

Parameters: p – Double3DTuple
Return type: float

Original perlin noise at location (C2 interpolant)

NatronEngine.ExprUtils.noise(p)

Parameters: p – ColorTuple
Return type: float

Original perlin noise at location (C2 interpolant)

NatronEngine.ExprUtils.snoise(p)

Parameters: p – Double3DTuple
Return type: float

Signed noise w/ range -1 to 1 formed with original perlin noise at location (C2 interpolant)

NatronEngine.ExprUtils.vnoise(p)

Parameters: p – Double3DTuple
Return type: Double3DTuple

Vector noise formed with original perlin noise at location (C2 interpolant)

NatronEngine.ExprUtils.cnoise(p)

Parameters: p – Double3DTuple
Return type: Double3DTuple

Color noise formed with original perlin noise at location (C2 interpolant)

NatronEngine.ExprUtils.snoise4(p)

Parameters: p – ColorTuple
Return type: float

4D signed noise w/ range -1 to 1 formed with original perlin noise at location (C2 interpolant)

NatronEngine.ExprUtils.vnoise4(p)

Parameters: p – ColorTuple
Return type: Double3DTuple

4D vector noise formed with original perlin noise at location (C2 interpolant)

NatronEngine.ExprUtils.cnoise4(p)

Parameters: p – ColorTuple
Return type: Double3DTuple

4D color noise formed with original perlin noise at location (C2 interpolant)”

NatronEngine.ExprUtils.turbulence(p[, ocaves=6, lacunarity=2, gain=0.5])

Parameters

p – Double3DTuple
octaves – int
lacunarity – float
gain – float

Return type

float

FBM (Fractal Brownian Motion) is a multi-frequency noise function. The base frequency is the same as the noise function. The total number of frequencies is controlled by octaves. The lacunarity is the spacing between the frequencies - A value of 2 means each octave is twice the previous frequency. The gain controls how much each frequency is scaled relative to the previous frequency.

NatronEngine.ExprUtils.vturbulence(p[, ocaves=6, lacunarity=2, gain=0.5])

Parameters

p – Double3DTuple
octaves – int
lacunarity – float
gain – float

Return type

Double3DTuple

FBM (Fractal Brownian Motion) is a multi-frequency noise function. The base frequency is the same as the noise function. The total number of frequencies is controlled by octaves. The lacunarity is the spacing between the frequencies - A value of 2 means each octave is twice the previous frequency. The gain controls how much each frequency is scaled relative to the previous frequency.

NatronEngine.ExprUtils.cturbulence(p[, ocaves=6, lacunarity=2, gain=0.5])

Parameters

p – Double3DTuple
octaves – int
lacunarity – float
gain – float

Return type

Double3DTuple

FBM (Fractal Brownian Motion) is a multi-frequency noise function. The base frequency is the same as the noise function. The total number of frequencies is controlled by octaves. The lacunarity is the spacing between the frequencies - A value of 2 means each octave is twice the previous frequency. The gain controls how much each frequency is scaled relative to the previous frequency.

NatronEngine.ExprUtils.fbm(p[, ocaves=6, lacunarity=2, gain=0.5])

Parameters

p – Double3DTuple
octaves – int
lacunarity – float
gain – float

Return type

float

FBM (Fractal Brownian Motion) is a multi-frequency noise function. The base frequency is the same as the noise function. The total number of frequencies is controlled by octaves. The lacunarity is the spacing between the frequencies - A value of 2 means each octave is twice the previous frequency. The gain controls how much each frequency is scaled relative to the previous frequency.

NatronEngine.ExprUtils.vfbm(p[, ocaves=6, lacunarity=2, gain=0.5])

Parameters

p – Double3DTuple
octaves – int
lacunarity – float
gain – float

Return type

Double3DTuple

FBM (Fractal Brownian Motion) is a multi-frequency noise function. The base frequency is the same as the noise function. The total number of frequencies is controlled by octaves. The lacunarity is the spacing between the frequencies - A value of 2 means each octave is twice the previous frequency. The gain controls how much each frequency is scaled relative to the previous frequency.

NatronEngine.ExprUtils.fbm4(p[, ocaves=6, lacunarity=2, gain=0.5])

Parameters

p – Double3DTuple
octaves – int
lacunarity – float
gain – float

Return type

float

FBM (Fractal Brownian Motion) is a multi-frequency noise function. The base frequency is the same as the noise function. The total number of frequencies is controlled by octaves. The lacunarity is the spacing between the frequencies - A value of 2 means each octave is twice the previous frequency. The gain controls how much each frequency is scaled relative to the previous frequency.

NatronEngine.ExprUtils.vfbm4(p[, ocaves=6, lacunarity=2, gain=0.5])

Parameters

p – Double3DTuple
octaves – int
lacunarity – float
gain – float

Return type

Double3DTuple

FBM (Fractal Brownian Motion) is a multi-frequency noise function. The base frequency is the same as the noise function. The total number of frequencies is controlled by octaves. The lacunarity is the spacing between the frequencies - A value of 2 means each octave is twice the previous frequency. The gain controls how much each frequency is scaled relative to the previous frequency.

NatronEngine.ExprUtils.cfbm(p[, ocaves=6, lacunarity=2, gain=0.5])

Parameters

p – Double3DTuple
octaves – int
lacunarity – float
gain – float

Return type

Double3DTuple

FBM (Fractal Brownian Motion) is a multi-frequency noise function. The base frequency is the same as the noise function. The total number of frequencies is controlled by octaves. The lacunarity is the spacing between the frequencies - A value of 2 means each octave is twice the previous frequency. The gain controls how much each frequency is scaled relative to the previous frequency.

NatronEngine.ExprUtils.cfbm4(p[, ocaves=6, lacunarity=2, gain=0.5])

Parameters

p – Double3DTuple
octaves – int
lacunarity – float
gain – float

Return type

Double3DTuple

FBM (Fractal Brownian Motion) is a multi-frequency noise function. The base frequency is the same as the noise function. The total number of frequencies is controlled by octaves. The lacunarity is the spacing between the frequencies - A value of 2 means each octave is twice the previous frequency. The gain controls how much each frequency is scaled relative to the previous frequency.

NatronEngine.ExprUtils.cellnoise(p)

Parameters

p – Double3DTuple

Return type

float

cellnoise generates a field of constant colored cubes based on the integer location This is the same as the prman cellnoise function

NatronEngine.ExprUtils.ccellnoise(p)

Parameters: p – Double3DTuple
Return type: Double3DTuple

cellnoise generates a field of constant colored cubes based on the integer location This is the same as the prman cellnoise function

NatronEngine.ExprUtils.pnoise(p, period)

Parameters

p – Double3DTuple
period – Double3DTuple

Return type

float

Periodic noise