ExprUtils¶
Inherits Double2DParam
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
 x –

NatronEngine.ExprUtils.
linearstep
(x, a, b)¶ Parameters:  x –
float
 a –
float
 b –
float
Return type: float
Transitions linearly when a < x < b
 x –

NatronEngine.ExprUtils.
boxstep
(x, a, b) Parameters:  x –
float
 a –
float
 b –
float
Return type: float
Transitions smoothly (cubic) when a < x < b
 x –

NatronEngine.ExprUtils.
gaussstep
(x, a, b)¶ Parameters:  x –
float
 a –
float
 b –
float
Return type: float
Transitions smoothly (exponentially) when a < x < b
 x –

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
 x –

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
 x –

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 multifrequency 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.
 p –

NatronEngine.ExprUtils.
vturbulence
(p[, ocaves=6, lacunarity=2, gain=0.5])¶ Parameters:  p –
Double3DTuple
 octaves –
int
 lacunarity –
float
 gain –
float
Return type: FBM (Fractal Brownian Motion) is a multifrequency 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.
 p –

NatronEngine.ExprUtils.
cturbulence
(p[, ocaves=6, lacunarity=2, gain=0.5])¶ Parameters:  p –
Double3DTuple
 octaves –
int
 lacunarity –
float
 gain –
float
Return type: FBM (Fractal Brownian Motion) is a multifrequency 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.
 p –

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 multifrequency 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.
 p –

NatronEngine.ExprUtils.
vfbm
(p[, ocaves=6, lacunarity=2, gain=0.5])¶ Parameters:  p –
Double3DTuple
 octaves –
int
 lacunarity –
float
 gain –
float
Return type: FBM (Fractal Brownian Motion) is a multifrequency 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.
 p –

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 multifrequency 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.
 p –

NatronEngine.ExprUtils.
vfbm4
(p[, ocaves=6, lacunarity=2, gain=0.5])¶ Parameters:  p –
Double3DTuple
 octaves –
int
 lacunarity –
float
 gain –
float
Return type: FBM (Fractal Brownian Motion) is a multifrequency 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.
 p –

NatronEngine.ExprUtils.
cfbm
(p[, ocaves=6, lacunarity=2, gain=0.5])¶ Parameters:  p –
Double3DTuple
 octaves –
int
 lacunarity –
float
 gain –
float
Return type: FBM (Fractal Brownian Motion) is a multifrequency 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.
 p –

NatronEngine.ExprUtils.
cfbm4
(p[, ocaves=6, lacunarity=2, gain=0.5])¶ Parameters:  p –
Double3DTuple
 octaves –
int
 lacunarity –
float
 gain –
float
Return type: FBM (Fractal Brownian Motion) is a multifrequency 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.
 p –

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
 p –