`sand_shadow`¶

Sand shadows: a tapering sand tail in the lee of each boulder of the nearest boulder layer before this one; lays sand over the material map.

Key	Type	Default	Range	Unit	Description
`wind_azimuth`	number	`0.0`		rad	Where the wind blows toward, in radians counter-clockwise from +x (local east on a body).
`length_ratio`	number	`1.1`	(0, inf)		Length of a tail beyond its boulder over the boulder's width; 1.1 is the reattachment length behind a dome, and modelled shadow dunes run 1.3 to 5.6, longer in lighter winds.
`flank_angle`	number	`0.5585053606381855`	(0, 1.5708)	rad	Slope of a tail's flanks, in radians, at most the angle of repose (about 32 deg for dry sand); sets the tail's height with the boulder's width.
`min_diameter`	number	`0.0`	[0, inf)	m	Smallest boulder with a tail, in metres.
`cover_thickness`	number	`0.02`	(0, inf)	m	Sand depth that fully covers the ground in the material map, in metres.

fade: How tails behind boulders too small for the sample spacing fade out, by samples across the boulder.

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": "sand_shadow",
    "wind_azimuth": 0.0,
    "length_ratio": 1.1,
    "flank_angle": 0.5585053606381855,
    "min_diameter": 0.0,
    "cover_thickness": 0.02,
    "fade": {
        "start_samples": 2.0,
        "end_samples": 4.0,
        "shape": "smoothstep"
    }
}

Used in: example_planets_mars_sand_shadows

sand_shadow¶

`sand_shadow`¶