Planetary

Generated from the schema registry by ernie schema --markdown.

Terrain

Heights displacing a body's surface, or a plane.

Prim type · Inherits Gprim

Attribute	Type	Description	Fallback	Values	Source
ernie:terrain:body	rel	The Sphere whose surface the heights displace, along its geodetic normals; unset, a plane in the terrain's xy plane.	""		Ernie
ernie:terrain:heights	float tensor, rank 2 or 3	float32 (rows, columns) heights in metres, the first row the northern; on a body, (6, n + 1, n + 1) cube faces.			Ernie
ernie:terrain:heights:file	asset	Heights as a raster (TIFF, PDS3, PNG or JPEG) in place of the array, paged as views need them.	""		Ernie
ernie:terrain:heights:unit	double	Metres in a unit of the file's values: 1000 for kilometres.	1.0	> 0	Ernie
ernie:terrain:heights:reference	double	Metres subtracted from the file's values: the radius, for files of radii.	0.0		Ernie
ernie:terrain:noData	double	The height marking missing cells; unauthored, every cell is a height.	0.0		Ernie
ernie:terrain:origin	double2	A plane's north-west corner in its x and y, metres.	[0.0,0.0]		Ernie
ernie:terrain:cellSize	double	Metres between a plane's heights.	1.0	> 0	Ernie
ernie:terrain:exaggeration	double	Scales the heights as drawn.	1.0	≥ 0	Ernie
ernie:terrain:finestCell	double	Metres: a body's LOD refines below its heights, bilinearly, to quads this size; 0 stops at the heights'.	1.0	≥ 0	Ernie
ernie:terrain:colorMode	token	shaded: its material, lit; colormap: a height ramp, unlit; shadedColormap: both; hillshade: a GIS hillshade, grey and unlit.	"shaded"	shaded, colormap, shadedColormap, hillshade	Ernie
ernie:terrain:hillshade:azimuth	double	Degrees clockwise from north of the hillshade's light; GIS's 315, from the north-west.	315.0	≥ 0, ≤ 360	Ernie
ernie:terrain:hillshade:altitude	double	Degrees above the horizon of the hillshade's light.	45.0	≥ 0, ≤ 90	Ernie

{
  "$schema": "https://alexmaietta.github.io/ernie/schema/ernie-scene.schema.json",
  "prims": {
    "/World/Terrain": {
      "typeName": "Terrain",
      "ernie:terrain:heights:unit": 1.0,
      "ernie:terrain:heights:reference": 0.0,
      "ernie:terrain:noData": 0.0,
      "ernie:terrain:origin": [0.0, 0.0],
      "ernie:terrain:cellSize": 1.0,
      "ernie:terrain:exaggeration": 1.0,
      "ernie:terrain:finestCell": 1.0,
      "ernie:terrain:colorMode": "shaded",
      "ernie:terrain:hillshade:azimuth": 315.0,
      "ernie:terrain:hillshade:altitude": 45.0
    }
  }
}

Atmosphere

The air around a body: its constituents, haze and clouds.

Prim type · Inherits Xformable

Attribute	Type	Description	Fallback	Values	Source
ernie:atmosphere:body	rel	The Sphere it surrounds.	""		Ernie
ernie:atmosphere:preset	token	Its physical model: Earth's air, ozone and haze, or Mars's carbon dioxide and dust.	"earth"	earth, mars	Ernie
ernie:atmosphere:top	double	Metres above the surface it reaches; Earth's 100 km.	100000.0	≥ 0	Ernie
ernie:atmosphere:groundAlbedo	double	The ground's reflectance for light scattered in the air.	0.3	≥ 0, ≤ 1	Ernie
ernie:atmosphere:hazeOpticalDepth	double	Earth: the haze's vertical optical depth at 550 nm.	0.1	≥ 0	Ernie
ernie:atmosphere:ozoneColumn	double	Earth: total column ozone, Dobson units.	300.0	≥ 0	Ernie
ernie:atmosphere:sodiumColumn	double	Earth: mesospheric sodium atoms per square metre, lit 92 km up by a 589 nm laser as a guide star.	40000000000000.0	≥ 0	Ernie
ernie:atmosphere:dustOpticalDepth	double	Mars: the dust's vertical optical depth at 880 nm.	0.5	≥ 0	Ernie
ernie:atmosphere:cloudTop	double	Metres below which clouds block light grazing the limb, darkening its shadow as in a lunar eclipse; 0 clear.	0.0	≥ 0	Ernie
ernie:atmosphere:cloudCover	double	The fraction of the limb the clouds cover.	0.5	≥ 0, ≤ 1	Ernie
ernie:polarization:degree	double	The sky's greatest degree of linear polarization, 90 degrees from the sun.	0.75	≥ 0, ≤ 1	Ernie

{
  "$schema": "https://alexmaietta.github.io/ernie/schema/ernie-scene.schema.json",
  "prims": {
    "/World/Atmosphere": {
      "typeName": "Atmosphere",
      "ernie:atmosphere:preset": "earth",
      "ernie:atmosphere:top": 100000.0,
      "ernie:atmosphere:groundAlbedo": 0.3,
      "ernie:atmosphere:hazeOpticalDepth": 0.1,
      "ernie:atmosphere:ozoneColumn": 300.0,
      "ernie:atmosphere:sodiumColumn": 40000000000000.0,
      "ernie:atmosphere:dustOpticalDepth": 0.5,
      "ernie:atmosphere:cloudTop": 0.0,
      "ernie:atmosphere:cloudCover": 0.5,
      "ernie:polarization:degree": 0.75
    }
  }
}

StarField

The stars, from a catalogue or arrays, at infinity: a light, unbounded.

Prim type · Inherits NonboundableLightBase

Attribute	Type	Description	Fallback	Values	Source
ernie:stars:magnitudeLimit	double	Stars fainter than this are left out.	99.0		Ernie
ernie:stars:zeroPoint	double	Lux of a magnitude 0 star (Allen's Astrophysical Quantities).	2.54e-06	> 0	Ernie
ernie:stars:magnitude	float[]	float32 (stars): apparent visual (Johnson V) magnitudes.			Ernie
ernie:stars:rightAscension	float[]	float32 (stars), degrees, in the catalogue's frame.			Ernie
ernie:stars:declination	float[]	float32 (stars), degrees, in the catalogue's frame.			Ernie
ernie:stars:direction	float[n, 3]	float32 (stars, 3) unit directions in its own space, in place of right ascension and declination.			Ernie
ernie:stars:colorIndex	float[]	float32 (stars): B-V colour indices, giving each star's temperature.			Ernie
ernie:stars:temperature	float[]	float32 (stars) kelvin, in place of the colour indices; without either, the Sun's 5772 K.			Ernie

{
  "$schema": "https://alexmaietta.github.io/ernie/schema/ernie-scene.schema.json",
  "prims": {
    "/World/StarField": {
      "typeName": "StarField",
      "ernie:stars:magnitudeLimit": 99.0,
      "ernie:stars:zeroPoint": 2.54e-06
    }
  }
}

GroundPlane

An infinite plane in its xy plane, facing +z.

Prim type · Inherits Gprim

Attribute	Type	Description	Fallback	Values	Source
ernie:checker	bool	Multiplies its material's albedo by checker squares.	false		Ernie
ernie:checker:size	double	Metres along a square's edge.	1.0	> 0	Ernie
ernie:checker:color0	color3d	Linear RGB.	[1.0,1.0,1.0]	≥ 0	Ernie
ernie:checker:color1	color3d	Linear RGB.	[0.5,0.5,0.5]	≥ 0	Ernie

{
  "$schema": "https://alexmaietta.github.io/ernie/schema/ernie-scene.schema.json",
  "prims": {
    "/World/GroundPlane": {
      "typeName": "GroundPlane",
      "ernie:checker": false,
      "ernie:checker:size": 1.0,
      "ernie:checker:color0": [1.0, 1.0, 1.0],
      "ernie:checker:color1": [0.5, 0.5, 0.5]
    }
  }
}