`bedforms`¶

Fields of wind-blown ripples or dunes added to the terrain.

Key	Type	Default	Range	Unit	Description
`wavelength`	number	`1.0`	(0, inf)	m	Crest-to-crest spacing, in metres; each field's varies from 0.8 to 1.2 times it.
`height`	number	`0.1`	[0, inf)	m	Trough-to-crest height, in metres, scaled with each field's wavelength.
`wind_azimuth`	number	`0.0`		rad	Direction the wind blows toward, in radians counter-clockwise from +x (local east on a sphere); crests lie across it.
`azimuth_spread`	number	`0.0`	[0, inf)	rad	Largest difference of each field's wind from the azimuth, in radians.
`lee_fraction`	number	`0.5`	(0, 1)		Share of a wavelength the lee face takes, in (0, 1): 0.5 is symmetric, lower values give a steeper lee face.
`sinuosity`	number	`0.5`	[0, inf)		How far a crest wanders along its length, in wavelengths; 0 gives straight crests.
`cover`	number	`0.0`	[0, 0.9]		Share of the ground under bedform fields, from 0 to 0.9; 0 gives no bedforms.
`field_size`	number	`100.0`	(0, inf)	m	Typical width of a bedform field, in metres.
`seed`	integer	`1`			Seed of the fields and their crests; changing it gives a different layout of the same statistics.
`exposure_spacing`	number	`1.0`	(0, inf)	m	Spacing in metres the ground is read at for the exposure field.

exposure: Leaves out fields whose centres lie on bedrock, the likelier the barer the ground, as sand settles in lows; unset disables it.

Key	Type	Default	Range	Unit	Description
`reach`	number	`12.0`	(0, inf)	m	Distance in metres around a point at which its surroundings are read, to tell rises from lows.
`rise_soil`	number	`0.01`			Height above the surroundings, as a share of the reach, at or below which the ground is soil.
`rise_boulder`	number	`0.035`			Height above the surroundings, as a share of the reach, at or above which the ground is bedrock; above the soil threshold.
`slope_soil`	number	`0.2`			Slope, as rise over run, at or under which soil holds.
`slope_boulder`	number	`0.4`			Slope, as rise over run, at or over which no soil holds and the ground is bedrock; above the soil threshold.
`floor_cover`	number	`0.0`	[0, 1)		Share of level ground that is bedrock too, in noise patches, as on a swept lava floor; from 0 to below 1, and 0 for none.
`floor_patch`	number	`60.0`	(0, inf)	m	Width of the bedrock patches on level ground, in metres.
`seed`	integer	`0`			Seed of the bedrock patches on level ground.

fade: How bedforms too fine for 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": "bedforms",
    "wavelength": 1.0,
    "height": 0.1,
    "wind_azimuth": 0.0,
    "azimuth_spread": 0.0,
    "lee_fraction": 0.5,
    "sinuosity": 0.5,
    "cover": 0.0,
    "field_size": 100.0,
    "seed": 1,
    "exposure": null,
    "exposure_spacing": 1.0,
    "fade": {
        "start_samples": 2.0,
        "end_samples": 4.0,
        "shape": "smoothstep"
    }
}

Used in: example_planets_mars_bedforms, example_planets_mars_exposure, example_planets_mars_sand_fill

bedforms¶

`bedforms`¶