noise_worley: Worley (cell) noise generator

In thomasp85/ambient: A Generator of Multidimensional Noise

Worley (cell) noise generator

Description

Worley noise, sometimes called cell (or cellular) noise, is quite distinct due to it's kinship to voronoi tesselation. It is created by sampling random points in space and then for any point in space measure the distance to the closest point. The noise can be modified further by changing either the distance measure or by combining multiple distances. The noise algorithm was developed by Steven Worley in 1996 and has been used to simulated water and stone textures among other things.

Usage

noise_worley(
  dim,
  frequency = 0.01,
  distance = "euclidean",
  fractal = "none",
  octaves = 3,
  lacunarity = 2,
  gain = 0.5,
  value = "cell",
  distance_ind = c(1, 2),
  jitter = 0.45,
  pertubation = "none",
  pertubation_amplitude = 1
)

gen_worley(
  x,
  y = NULL,
  z = NULL,
  frequency = 1,
  seed = NULL,
  distance = "euclidean",
  value = "cell",
  distance_ind = c(1, 2),
  jitter = 0.45,
  ...
)

Arguments

dim	The dimensions (height, width, (and depth)) of the noise to be generated. The length determines the dimensionality of the noise.
frequency	Determines the granularity of the features in the noise.
distance	The distance measure to use, either 'euclidean' (default), 'manhattan', or 'natural' (a mix of the two)
fractal	The fractal type to use. Either 'none', 'fbm' (default), 'billow', or 'rigid-multi'. It is suggested that you experiment with the different types to get a feel for how they behaves.
octaves	The number of noise layers used to create the fractal noise. Ignored if fractal = 'none'. Defaults to 3.
lacunarity	The frequency multiplier between successive noise layers when building fractal noise. Ignored if fractal = 'none'. Defaults to 2.
gain	The relative strength between successive noise layers when building fractal noise. Ignored if fractal = 'none'. Defaults to 0.5.
value	The noise value to return. Either 'value' (default) A random value associated with the closest point 'distance' The distance to the closest point 'distance2' The distance to the nth closest point (n given by distance_ind[1]) 'distance2add' Addition of the distance to the nth and mth closest point given in distance_ind 'distance2sub' Substraction of the distance to the nth and mth closest point given in distance_ind 'distance2mul' Multiplication of the distance to the nth and mth closest point given in distance_ind 'distance2div' Division of the distance to the nth and mth closest point given in distance_ind
distance_ind	Reference to the nth and mth closest points that should be used when calculating value.
jitter	The maximum distance a point can move from its start position during sampling of cell points.
pertubation	The pertubation to use. Either 'none' (default), 'normal', or 'fractal'. Defines the displacement (warping) of the noise, with 'normal' giving a smooth warping and 'fractal' giving a more eratic warping.
pertubation_amplitude	The maximal pertubation distance from the origin. Ignored if pertubation = 'none'. Defaults to 1.
x, y, z	Coordinates to get noise value from
seed	The seed to use for the noise. If NULL a random seed will be used
...	ignored

Value

For noise_worley() a matrix if length(dim) == 2 or an array if length(dim) == 3. For gen_worley() a numeric vector matching the length of the input.

References

Worley, Steven (1996). A cellular texture basis function. Proceedings of the 23rd annual conference on computer graphics and interactive techniques. pp. 291–294. ISBN 0-89791-746-4

Examples

# Basic use
noise <- noise_worley(c(100, 100))

plot(as.raster(normalise(noise)))

# Using the generator and another value metric
grid <- long_grid(seq(1, 10, length.out = 1000), seq(1, 10, length.out = 1000))
grid$noise <- gen_worley(grid$x, grid$y, value = 'distance')
plot(grid, noise)

thomasp85/ambient documentation built on Sept. 14, 2022, 8:02 a.m.