`roughness`¶

Fine roughness from octaves of noise, scaled to a given RMS slope over a baseline.

Key	Type	Default	Range	Unit	Description
`rms_slope`	number	`0.15`	(0, inf)		RMS slope, as rise over run, over the baseline when every octave is resolved; higher values give rougher ground.
`baseline`	number	`0.25`	(0, inf)	m	Baseline the RMS slope is given over, in metres.
`hurst`	number	`0.8`	(0, 1]		Hurst exponent, in (0, 1]: octave amplitudes grow as wavelength^hurst, so lower values put relatively more roughness at short wavelengths.
`max_wavelength`	number	`4.0`	(0, inf)	m	Wavelength of the longest octave, in metres.
`min_wavelength`	number	`0.01`	(0, inf)	m	Wavelength of the shortest octave, in metres; octaves halve from the longest down to it, spanning at most 40 octaves.
`seed`	integer	`1`			Seed of the noise; changing it gives a different pattern of the same roughness.

fade: How octaves too fine to resolve at the sample spacing fade out, by samples per wavelength.

Key	Type	Default	Range	Description
`start_samples`	number	`2.0`	[0, inf)	Samples across a feature's diameter up to which it is left out entirely.
`end_samples`	number	`4.0`	(0, inf)	Samples across a feature's diameter from which it is applied in full; it fades in between the two counts.
`shape`	one of `linear`, `smoothstep`, `smootherstep`, `gaussian`	`"smoothstep"`		Curve of the fade between the start and end sample counts.

Every key with its default

{
    "type": "roughness",
    "rms_slope": 0.15,
    "baseline": 0.25,
    "hurst": 0.8,
    "max_wavelength": 4.0,
    "min_wavelength": 0.01,
    "seed": 1,
    "fade": {
        "start_samples": 2.0,
        "end_samples": 4.0,
        "shape": "smoothstep"
    }
}

Used in: example_albedo_fresh_crater, example_boulders_buried, example_boulders_fragments, example_craters_texture, example_layers_roughness

roughness¶

`roughness`¶