Components

This section lists all components, together with a description and all the attributes. For each attribute, we provide a description and list its units and possible aliases. We also note the Archetypes that have the component.

A general description of archetypes and components is provided in Data morphology.

All components are: Base, Body, GraphNode, Coordinates, Orientation, Celestial, Magnitude, ProperMotion, SolidAngle, Shape, Trajectory, ModelScaffolding, Model, Volume, Atmosphere, Cloud, RenderFlags, MotorEngine, RefSysTransform, AffineTransformations, Fade, DatasetDescription, Label, RenderType, BillboardSet, Title, Axis, LocationMark, Constel, Boundaries, ParticleSet, StarSet, ParticleExtra, Mesh, Focus, Raymarching, Highlight.

Base

Defines basic attributes common to all objects.

This component is in the following archetypes: SceneGraphNode, Universe.

Base attributes

Attribute

Description

Aliases

id

The ID of the object, typically set automatically by Gaia Sky.

name

A single object name, used to identify the object and as a label text, if any. If the object already has names, this attribute overrides the first one in the name list. The first name in the list is also used as the i18n key for translations.

names

A list of names, used to identify the object. It overrides the full name list. The first name in the list is used as a label text, and as a i18n key.

altName

Adds a new name to the name list of this object, at the end.

altname

opacity

Static opacity value. Typically, this gets overwritten internally in the update process.

componentType

The content type string (or list) for this object. Content types control the visibility of objects. Examples of content types are ‘Planets’, ‘Asteroids’, ‘Stars’, ‘Labels’, etc.

ct, componentTypes

Body

Defines physical body attributes common to all objects.

This component is in the following archetypes: SceneGraphNode, Universe.

Body attributes

Attribute

Description

Aliases

position

The position of the object. This is the position at epoch if the object has a proper motion, or just a static position. Given in the internal reference system and in internal units by default (see aliases for other units).

pos, positionKm, posKm, positionPc, posPc

size

The diameter of the entity (in some archetypes this is the radius). The default attribute uses internal units (see aliases for other units).

sizeKm, sizePc, sizepc, sizeM, sizeAU, diameter, diameterKm, diameterPc

cameraCollision

Enable or disable camera collision with this object’s bounding sphere. This means that the camera is not permitted to enter this object’s radius.

radius

The half-size. See size attribute.

radiusKm, radiusPc

color

The color of the entity, as a RGBA quartet. Used as the general color of the entity. The last value in the list, alpha, also acts as a transparency value. The color is also applied to the object label unless ‘labelColor’ is specified.

labelColor

The color of the label of this entity. If set, the label of this entity uses this color. Otherwise, it uses the global entity color.

labelcolor

GraphNode

Defines attributes pertaining to the scene graph hierarchy.

This component is in the following archetypes: SceneGraphNode, Universe.

GraphNode attributes

Attribute

Description

Aliases

parent

Name of the parent entity in the scene graph. Positions for every object are typically relative to the position of the parent. In some cases, the orientation of the parent is also contemplated.

Coordinates

Defines attributes that provide coordinates and positions to objects.

This component is in the following archetypes: CelestialBody, BackgroundModel, BillboardGroup, Model.

Coordinates attributes

Attribute

Description

Aliases

coordinatesProvider

The coordinates provider object for this object. The coordinates provider computes the position of the object for each time. This is an object containing, at least, the full reference to a Java class that implements IBodyCoordinates in the “impl” attribute. Examples are gaiasky.util.coord.StaticCoordinates or gaiasky.util.coord.OrbitLintCoordinates. See Locations for more information.

coordinates

Orientation

Defines the orientation model of objects. Can be defined as a rigid rotation (given parameters like rotation period, axial tilt, etc.) or via quaternion-based orientations.

This component is in the following archetypes: CelestialBody, Satellite.

Orientation attributes

Attribute

Description

Aliases

rotation

The rotation object for this object. This attribute describes a rigid body rotation. This is given in the form of a map with the attributes angularVelocity, period, axialtilt, inclination, ascendingNode and meridianAngle. See Orientation for more information.

rigidRotation

orientationProvider

Provider class for the quaternion orientations.

provider, attitudeProvider

orientationSource

Location of the data file(s), necessary to initialize the quaternion orientation provider.

attitudeLocation

Celestial

Defines attributes common to all celestial objects (stars, planets, moons, etc.).

This component is in the following archetypes: CelestialBody.

Celestial attributes

Attribute

Description

Aliases

wikiName

The name to look up this object in the wikipedia, if any. If this is set, a ‘+ info’ button appears in the focus info interface when this object is the focus, enabling the user to pull information on the object directly from Gaia Sky and display it in a window.

wikiname

colorBV

The color index B-V of this object. This is only ever used in single particles/stars, and when no ‘color’ attribute has been specified. If that is the case, we convert the B-V index into an RGB color and use it as the object’s global color.

colorbv, colorBv, colorIndex

Magnitude

Defines magnitude attributes, both apparent and absolute.

This component is in the following archetypes: CelestialBody.

Magnitude attributes

Attribute

Description

Aliases

appMag

The apparent magnitude. If it is not given, it is computed automatically from the absolute magnitude (if present) and the distance.

appmag, apparentMagnitude

absMag

The absolute magnitude. If it is not given, it is computed automatically from the apparent magnitude (if present) and the distance. In single stars, the absolute magnitude is used to compute the pseudo-size. See the ‘star rendering’ section for more information.

absmag, absoluteMagnitude

ProperMotion

Defines proper motion attributes.

This component is in the following archetypes: Particle, StarCluster.

ProperMotion attributes

Attribute

Description

Aliases

muAlpha

Proper motion in right ascension, the \mu_{\alpha\star}, in mas/yr.

muAlphaMasYr

muDelta

Proper motion in declination, the \mu_{\delta}, in mas/yr.

muDeltaMasYr

radialVelocity

The radial velocity, in km/s.

rv, rvKms, radialVelocityKms

epochJd

The epoch as a Julian date. For instance, 2015.5 corresponds to a Julian date of 2457206.125.

epochYear

The epoch as a year plus fraction (e.g. 2015.5). This gets converted to a Julian date internally.

SolidAngle

Defines solid angle thresholds for the various rendering modes.

This component is in the following archetypes: CelestialBody, StarCluster, Model.

SolidAngle attributes

Attribute

Description

Aliases

thresholdNone

Solid angle threshold to start rendering this object at all. Mainly for internal use. Gets overwritten during initialization.

thresholdPoint

Solid angle threshold boundary between rendering the object as a point and as a quad. Mainly for internal use. Gets overwritten during initialization.

thresholdQuad

Solid angle threshold boundary between rendering the object as a quad and as a model. Mainly for internal use. Gets overwritten during initialization.

Shape

Defines attributes related to shape objects

This component is in the following archetypes: ShapeObject.

Shape attributes

Attribute

Description

Aliases

track

Shape objects can use the position of other objects as their own. This is useful when, for example, we want to add a wireframe sphere around an object. This attribute contains the name of the object whose position we are to track.

trackName

Trajectory

Defines attributes related to orbits and trajectory objects. See Orbits for more information.

This component is in the following archetypes: Orbit.

Trajectory attributes

Attribute

Description

Aliases

orbitProvider

In Orbit archetype objects, this is the fully-qualified Java class that provides orbit data. This class needs to implement IOrbitDataProvider.

Values:
gaiasky.data.orbit.OrbitalParametersProvider – orbit is defined with orbital elements.
gaiasky.data.orbit.OrbitFileDataProvider – orbit defined from a file of 3D sample points, in Km.
See Orbits for more information.

provider

orbit

The orbit component, containing some additional information, like the orbital elements, the period, etc. See Orbits for a full description of the format and possible values of this attribute.

orientationModel

The orientation model of this orbit.

Values:
default – the default orientation.
extrasolar_system – orientation for extrasolar systems. See Orbits for more information.

model

onlyBody

In object-less orbits (orbits not attached to any object), it may be interesting to not render the orbit itself as a line, but only a point at the head of that orbit in the current time. If this attribute is set to true, the orbit is rendered as a single point at the head. Useful essentially to render many particles using orbital elements. This attribute is deprecated, use bodyRepresentation instead.

onlybody

bodyRepresentation

The body representation type for this orbit/trajectory. This only works with orbits defined via orbital elements.

Values:
only_orbit – the body is not visually represented at all.
only_body – only the body is visually represented, no line.
body_and_orbit – both body and orbit line are represented.

bodyColor

Body color. Color to use to represent the body in orbital elements trajectories, when the bodyRepresentation attribute enables the representation of the body for this trajectory.

pointColor, pointcolor

pointSize

The size of the point at the head of the trajectory in object-less orbits (orbits that are not attached to any object). Examples of this are asteroids, where orbits are defined via the orbital elements, and not all orbits are attached to an asteroid object for performance purposes. In these cases, the size of the point at the head of the orbit is set in this property.

pointsize

closedLoop

Define whether the loop must be closed or not (i.e. join the end point with the start point). Defaults to true, which is the value for periodic orbits.

orbitTrail

Whether to fade the orbit as it gets further away from the head (or object), in the opposite direction of travel. By default, the head is mapped to an opacity of 1, and the tail is mapped to an opacity of 0.

orbittrail, trail

trailMap

Modify the tail mapping value in case orbitTrail is set to true. This mapping parameter defines the location in the orbit (in [0,1]) where we map the opacity value of 0. The default value is 0. Set it to 0.5 to have a trail from the object to half the orbit. This enables having shorter trails, while improving the performance due to less lines being rendered.

trailMinOpacity

Minimum opacity level of the whole orbit in trail mode. Only active if orbitTrail is set to true. This parameter defines the minimum opacity of the orbit (in [0,1]). This enables having trails where the faint end maps to an opacity larger than zero, thus getting to see the whole orbit at all times.

newMethod

Internal parameter. Changes the way in which transformations are applied to the orbit objects. Asteroids have this set to true.

newmethod

numSamples

Override the number of samples to be used for this orbit. Gaia Sky computes the number of samples internally, but in some cases it may be necessary to override it to give orbits more detail.

orbitScaleFactor

Multiplicative factor to scale the orbit data points when they are being loaded.

multiplier

fadeDistanceUp

Override the distance at which the orbit becomes totally invisible. In internal units. If not overridden, this is computed internally from the radius of the attached body.

fadeDistanceDown

Override the distance at which the orbit starts to fade out. In internal units. If not overridden, this is computed internally from the radius of the attached body.

refreshRate

For orbits that need to be refreshed (i.e. not implemented as orbital elements, but via samples), this is the orbit refresh rate, in [0,1]. Set to 0 to recompute only every period, and set to 1 to recompute as often as possible. Set to negative to use the default re-computation heuristic. This can help reduce the visible seams that occur in the transitions from the trajectory lines computed in the period to the current period in orbits which are very open.

ModelScaffolding

Defines attributes related objects with 3D models.

This component is in the following archetypes: ModelBody, Star.

ModelScaffolding attributes

Attribute

Description

Aliases

referencePlane

The reference plane to use for this model object.

Values:
ecliptic
galactic
equatorial

refPlane, refplane

randomize

A list with the components of this model that need to be randomized via procedural generation. Can contain ‘model’, ‘atmosphere’, and/or ‘cloud’.

seed

In case the ‘randomize’ attribute is defined, this attribute defines the RNG seed to use.

sizeScaleFactor

Scale factor to apply to the 3D model of this object. Mainly used internally. Using the model or object attributes directly to specify the size is recommended.

sizescalefactor

locVaMultiplier

Solid angle multiplier for children location objects (Loc) of this object. If set, this scales the solid angle of the object for children locations.

locvamultiplier

locThresholdLabel

Threshold label value for children locations. Mainly used internally, should not be touched externally.

locThOverFactor, locthoverfactor

selfShadow

Whether to render self-shadows for this object.

shadowValues

Deprecated as of Gaia Sky 3.6.1.

shadowvalues

Model

Defines the actual model of objects with 3D models. See Model for more information.

This component is in the following archetypes: ModelBody, Star, StarCluster, MeshObject, BackgroundModel, RecursiveGrid, StarGroup, Model, VRDeviceModel.

Model attributes

Attribute

Description

Aliases

model

Model definition for this object. See the Model documentation for more information.

Volume

Defines a volume to be rendered inside a model, typically a bounding box.

This component is in the following archetypes: Volume.

Volume attributes

Attribute

Description

Aliases

vertexShader

The vertex shader to use. Prefix with $data to use a shader in a dataset. Defaults to the PBR vertex shader.

fragmentShader

The fragment shader to use. Prefix with $data to use a shader in a dataset.

Atmosphere

Defines the atmosphere of a planet or moon. See the Atmospheric scattering parameters documentation for more information.

This component is in the following archetypes: Planet.

Atmosphere attributes

Attribute

Description

Aliases

atmosphere

Atmosphere definition for this object. See the Atmospheric scattering parameters documentation for more information.

Cloud

Defines the cloud layer of a planet or moon. See the Clouds documentation for more information.

This component is in the following archetypes: Planet.

Cloud attributes

Attribute

Description

Aliases

cloud

Cloud layer definition for this object. See the Clouds documentation for more information.

RenderFlags

Defines rendering flags.

This component is in the following archetypes: GenericSpacecraft.

RenderFlags attributes

Attribute

Description

Aliases

renderQuad

Whether to render this entity as a billboard (quad).

renderquad

MotorEngine

Defines machines for the spacecraft mode.

This component is in the following archetypes: Spacecraft.

MotorEngine attributes

Attribute

Description

Aliases

machines

Provides machine definitions for the spacecraft mode. Check out the spacecraft object definition in the default data pack for more information.

RefSysTransform

Defines an arbitrary reference system transformation via a 4x4 matrix. See Reference system transformations for more information.

This component is in the following archetypes: Orbit, GenericCatalog, MeshObject, BackgroundModel, RecursiveGrid, Axes, Model.

RefSysTransform attributes

Attribute

Description

Aliases

transformFunction

Defines a transformation matrix to apply to the position of the object. The name of the transformation to apply.

Values:
equatorialToEcliptic
eclipticToEquatorial
equatorialToGalactic
galacticToEquatorial
eclipticToGalactic
galacticToEcliptic
See Reference system transformations for more information.

transformName

transformMatrix

The 16 values of the 4x4 transformation matrix, in column-major order. See Reference system transformations for more information.

transformValues

AffineTransformations

Defines arbitrary affine transformations, applied in the order they are defined. See Affine transformations for more information.

This component is in the following archetypes: ModelBody, Orbit, GenericCatalog, MeshObject, OctreeWrapper, Model.

AffineTransformations attributes

Attribute

Description

Aliases

matrix

A generic 4x4 matrix transform that will be applied to the sequence of affine transformations. The matrix values need to be in column-major order. See Affine transformations for more information.

transformMatrix

translate

A translation vector, in internal units (see aliases for other units). See Affine transformations for more information.

translatePc, translateKm

rotate

A rotation axis and angle, in degrees. The vector is expected as [X, Y, Z, angle]. See Affine transformations for more information.

scale

A scale transformation. Can be a 3-vector or a single value. See Affine transformations for more information.

transformations

Describe the transformations directly in a map, with ‘impl’, and whatever attributes. The usage of the attributes ‘translate’, ‘scale’ and ‘rotate’ is strongly recommended over this.

Fade

Defines the properties that control the fading in and out of the object.

This component is in the following archetypes: Billboard, FadeNode, RecursiveGrid, Text2D, OctreeWrapper.

Fade attributes

Attribute

Description

Aliases

fadeIn

The starting and ending fade-in distances, in parsecs, from the reference system origin (unless ‘fadeObjectName’ or ‘fadePosition’ are defined, in which case the distances are relative to the given object or position), where the object starts and ends its fade-in transition.

fadein

fadeInMap

The alpha/opacity values to which the fade-in starting and ending distances are mapped. They default to [0,1].

fadeOut

The starting and ending fade-out distances, in parsecs, from the reference system origin (unless ‘fadeObjectName’ or ‘fadePosition’ are defined, in which case the distances are relative to the given object or position), where the object starts and ends its fade-out transition.

fadeout

fadeOutMap

The alpha/opacity values to which the fade-out starting and ending distances are mapped. They default to [1,0].

fadeObjectName

The name of the object to be used to compute the current distance for the fade in and out operations.

positionobjectname

fadePosition

The position, in the internal reference system and internal units, to be used to compute the current distance for the fade in and out operations.

DatasetDescription

Contains metadata about the dataset represented by this object. All objects with this component get an entry in the datasets list.

This component is in the following archetypes: GenericCatalog, MeshObject, OctreeWrapper.

DatasetDescription attributes

Attribute

Description

Aliases

catalogInfo

A map containing the metadata for the catalog represented by this object. The map can contain the attributes ‘name’, ‘description’, ‘type’ (INTERNAL|SCRIPT|LOD|SAMP|UI), ‘nParticles’, ‘sizebytes’. See Catalog formats for more information.

datasetInfo, cataloginfo

addDataset

Whether to add the dataset to the dataset manager or not. Typically used with star and particle sets that already belong to a higher-level dataset.

addToDatasetManager

Label

Defines attributes that control how labels are processed and rendered. See Labels for more information.

This component is in the following archetypes: CelestialBody, StarCluster, Orbit, FadeNode, BackgroundModel, RecursiveGrid, Text2D, Loc, StarGroup, Constellation, CosmicRuler, ShapeObject, KeyframesPathObject.

Label attributes

Attribute

Description

Aliases

label

A boolean to disable or enable label rendering for this object.

label2d

Unused, here for backwards compatibility.

labelPosition

Override the position at which to render this label, in the internal reference system and internal units (see aliases for more unit options). If this is not given, the position of the object is used.

labelposition, labelPositionPc, labelPositionKm

renderLabel

Defaults to true, this flag enables or disables the actual rendering of the label in the attached object.

forceLabel

Force-display the label of this object, regardless of its solid angle. If ‘true’, the label for this object is always displayed.

labelFactor

Factor to apply to the size of the label for this object.

labelBias

Bias to compute the label visibility. >1 to increase visibility.

labelMax

Internal rendering factor, should not be set externally.

textScale

Internal rendering factor, should not be set externally.

RenderType

Defines attributes that control rendering operations for this object.

This component is in the following archetypes: ModelBody, Particle, BackgroundModel, RecursiveGrid, Model.

RenderType attributes

Attribute

Description

Aliases

renderGroup

This is an internal property used to fine-tune exactly the environment and shader to use to render the object. See RenderGroup.java for more information.

rendergroup

BillboardSet

Defines attributes related to billboard set objects.

This component is in the following archetypes: BillboardGroup.

BillboardSet attributes

Attribute

Description

Aliases

data

A list of BillboardDataset objects. Mainly used for the Milky Way model. Each object contains ‘impl’, ‘file’, ‘type’, ‘size’, ‘intensity’, ‘layers’, and ‘maxsizes’. See the Milky Way object in the universe.json file in the default data pack for an example.

Title

Defines attributes related to two-dimensional titles.

This component is in the following archetypes: Text2D.

Title attributes

Attribute

Description

Aliases

scale

Scale factor to scale up or down the title.

lines

Whether to render frame lines above and below the title or not.

align

The horizontal alignment of the title. Center (1), left (8) or right (16).

Axis

Defines attributes related to reference system axes.

This component is in the following archetypes: Axes.

Axis attributes

Attribute

Description

Aliases

axesColors

A 3x3 matrix with the color for each of the axes in the reference system.

LocationMark

Defines attributes related to location objects. Location objects usually mark special points on the surface of objects, like cities, craters, etc. They have a label (text) and an optoinal marker. The label color is defined in the attribute ‘labelColor’, and the marker color is defined in the attribute ‘color’. See Locations for more information.

This component is in the following archetypes: Loc.

LocationMark attributes

Attribute

Description

Aliases

location

A 2-dimensional position [longitude, latitude] on the surface of the parent, in degrees.

tooltipText

Descriptive text to display as a tooltip when the mouse hovers over the location mark. Only locations with markers display tooltips.

link

A link (URL) to an external resource, preferrably Wikipedia, with more information about this location.

locationType

Additional categorization of locations. This is used only in the UI so that all locations in the same category can be turned on and off at the same time with a single click.

ignoreSolidAngleLimit

Ignore the solid angle upper limit when determining the visibility of this location. Setting this to true causes the location to not disappear, regardless of the camera distance.

locationMarkerTexture

Location marker texture (image). Set to ‘none’ to disable maker. Possible values are ‘none’, ‘default’, ‘flag’, ‘city’, or a path to a PNG image. If the path directs to a data package, the format is ‘$data/[package-name]/path/to/file.png’.

markerTexture

distFactor

Factor to apply to the radius of the parent object to get distance from the center of the object, in case of non-spherical parent objects. This modulates the distance of the location from the center of the object (radius), as the locations are given in [longitude, latitude, radius]. If this is not specified, the radius is that of the parent object. If you want the location to show at double the radius distance, use 2.0.

Constel

Defines attributes related to constellation objects.

This component is in the following archetypes: Constellation.

Constel attributes

Attribute

Description

Aliases

ids

Contains a list of segments (a list of lists of points) with the HIP identifiers for each of the stars of this constellation.

Boundaries

Defines attributes related to constellation boundary objects.

This component is in the following archetypes: ConstellationBoundaries.

Boundaries attributes

Attribute

Description

Aliases

boundaries

Contains a list of lists of sky coordinates (\alpha, \delta), in degrees, defining the lines of the constellation boundaries.

boundariesEquatorial

ParticleSet

Defines attributes related to particle set objects, which contain a point cloud.

This component is in the following archetypes: ParticleGroup.

ParticleSet attributes

Attribute

Description

Aliases

provider

The class to be used to load the data. This class must implement IParticleGroupDataProvider. This should have the fully-qualified class name. For instance, gaiasky.data.group.STILDataProvider.

providerParams

Parameters to be passed into the provider class.

providerparams

meanPosition

The mean position of this particle set, in the internal reference system and internal units (see aliases for more units). If not given, this is computed automatically from the particle positions.

meanPositionKm, meanPositionPc, pos, posKm, posPc, position

dataFile

The path to the data file with the particles to be loaded by the provider.

datafile

factor

A multiplicative factor to apply to the positions of all particles during loading.

numLabels

Number of labels to render for this particle group. Defaults to the configuration setting.

profileDecay

The profile decay of the particles in the shader. Controls how sudden is the color and intensity falloff from the center.

profiledecay

colorNoise

Noise factor for the color, in [0,1]. This randomly generates colors from the main color. The larger the color noise, the more different the generated colors from the main color.

colornoise

particleSizeLimits

Minimum and maximum solid angle limits of the particles in radians. They are used as (dist * tan(\alpha_{min}), dist * tan(\alpha_{max})). The minimum and maximum values must be in [0,1.57].

particlesizelimits, particleSizeLimitsDeg

colorMin

The color of the particles at the closest distance, as RGBA. If this is set, the color of the particles gets interpolated from colorMin to colorMax depending on the distance of the particles to the origin.

colorMax

The color of the particles at the maximum distance, as RGBA. If this is set, the color of the particles gets interpolated from colorMin to colorMax depending on the distance of the particles to the origin.

colorFromTexture

If true, color of this particle depends on the texture assigned to it. This is useful when using ‘textureAttribute’, for instance, where the texture is assigned depending on the value of an attribute for this object. This feature requires a non-zero ‘colorNoise’, as it is used to generate the colors.

fixedAngularSize

Set a fixed angular size for all particles in this set, as a solid angle in radians (see aliases for other units).

fixedAngularSizeDeg, fixedAngularSizeRad

renderSetLabel

Enable or disable the global label of this particle set. If true, the name of this particle set is rendered at the given label position.

renderParticles

Disable particle rendering by setting this to false. Labels, in case of star sets, will still be rendered.

texture

Texture file to render the particles of this group. This can also point to a directory, in which case all the image files within are used (they must have the same dimensions). If this is provided, profileDecay is ignored.

textures

List of texture files to render the particles of this group. If more than one texture is provided, each particle is assigned a texture randomly. This can also point to one or more directories, in which case all the image files within are used. All images must have the same dimensions. If this is provided, profileDecay is ignored.

textureAttribute

If present, this attribute is used to assign textures to particles. It should be an integer attribute in [1,n], where n is the number of textures. If the value of the attribute is out of this range, it is clamped. The attribute value is used as an index to query the texture array, where the textures are sorted using the natural order of their file names. If the attribute is of any other type, Gaia Sky will do its best to use it to assign textures as well, but no guarantees.

modelFile

Path to the model file to use (obj, obj.gz g3db, g3dj, gltf, glb). If present, the modelType and modelParams attributes are ignored. The model should have only positions (vector-3), normals (vector-3), and texture coordinates (vector-2) as vertex attributes. Only the first mesh of the model is used. Textures, lighting and material are ignored. This is only used in extended particle groups.

modelType

The model type to use for this particle set.

Values:
quad – render billboards.
sphere render UV spheres.
icosphere render icosahedron-based spheres.
Defaults to ‘quad’. This is only used in extended particle groups. To enable extended particle groups, you need to set ‘type’ to ‘PARTICLES_EXT’ in the ‘providerParams’ map.

modelParams

Model parameters in a map. Usually, the ‘diameter’, ‘width’, ‘height’, ‘recursion’ or ‘quality’ go here. For more info, see the gaiasky.util.ModeCache class. This is only used in extended particle groups.

modelPrimitive

The GL primitive to use.

Values:
GL_TRIANGLES
GL_TRIANGLE_STRIP
GL_TRIANGLE_FAN
GL_LINES
GL_LINE_STRIP
GL_LINE_LOOP
Defaults to GL_TRIANGLES. The GL_LINE primitives enable wireframe rendering, which is currently only supported by sphere and ico-sphere model types. This is only used in extended particle groups.

proximityDescriptorsLocation

Location of directory that contains descriptor JSON files that bear the names of objects in the dataset. These get loaded whenever the camera gets close to a particle.

proximityDescriptors, descriptorsLocation

proximityThreshold

Solid angle above which the proximity descriptor loading is triggered.

proximityThresholdDeg, proximityThresholdRad

StarSet

Defines attributes related to star set objects, which contain a star catalog or group.

This component is in the following archetypes: StarGroup.

StarSet attributes

Attribute

Description

Aliases

provider

The class to be used to load the data. This class must implement IParticleGroupDataProvider. This should have the fully-qualified class name. For instance, gaiasky.data.group.STILDataProvider.

providerParams

Parameters to be passed into the provider class.

providerparams

meanPosition

The mean position of this particle set, in the internal reference system and internal units (see aliases for more units). If not given, this is computed automatically from the particle positions.

meanPositionKm, meanPositionPc, pos, posKm, posPc, position

dataFile

The path to the data file with the particles to be loaded by the provider.

datafile

factor

A multiplicative factor to apply to the positions of all particles during loading.

profileDecay

The profile decay of the particles in the shader. Controls how sudden is the color and intensity falloff from the center.

profiledecay

colorNoise

Noise factor for the color, in [0,1]. This randomly generates colors from the main color. The larger the color noise, the more different the generated colors from the main color.

colornoise

particleSizeLimits

Minimum and maximum solid angle limits of the particles in radians. They are used as (dist * tan(\alpha_{min}), dist * tan(\alpha_{max})). The minimum and maximum values must be in [0,1.57].

particlesizelimits, particleSizeLimitsDeg

colorMin

The color of the particles at the closest distance, as RGBA. If this is set, the color of the particles gets interpolated from colorMin to colorMax depending on the distance of the particles to the origin.

colorMax

The color of the particles at the maximum distance, as RGBA. If this is set, the color of the particles gets interpolated from colorMin to colorMax depending on the distance of the particles to the origin.

fixedAngularSize

Set a fixed angular size for all particles in this set, as a solid angle in radians (see aliases for other units).

fixedAngularSizeDeg, fixedAngularSizeRad

renderParticles

Disable particle rendering by setting this to false. Labels, in case of star sets, will still be rendered.

epochJd

The epoch for the positions of this star group as a Julian date.

epoch

variabilityEpochJd

The light curve epoch for the variable stars in this star group as a Julian date.

variabilityEpoch

numLabels

Number of labels to render for this star group. Defaults to the configuration setting.

ParticleExtra

Defines attributes related to single particles and single star objects.

This component is in the following archetypes: Particle.

ParticleExtra attributes

Attribute

Description

Aliases

primitiveRenderScale

Artificial scale factor for the size of this particle during rendering.

tEff

Effective temperature of the star or body, in Kelvin.

teff

Mesh

Defines attributes related to meshes and iso-density surfaces. See Mesh objects for more information.

This component is in the following archetypes: MeshObject.

Mesh attributes

Attribute

Description

Aliases

shading

Shading mode for the mesh.

Values:
additive – additive blending.
dust – opaque mesh with dither transparency at the edges.
regular – regular general-purpose PBR shader.

additiveBlending

Sets the shading mode to ‘additive’.

additiveblending

Focus

Defines attributes related to objects that can be focussed.

This component is in the following archetypes: CelestialBody, StarCluster, ParticleGroup, StarGroup, Model.

Focus attributes

Attribute

Description

Aliases

focusable

Defines whether the object is focusable or not. Non-focusable objects do not appear in the search results and can’t be selected with the mouse. By default, this is true.

Raymarching

Defines attributes related to ray-marched objects.

This component is in the following archetypes: Invisible.

Raymarching attributes

Attribute

Description

Aliases

shader

Path to the fragment shader GLSL file to use to render this object. The fragment shader is processed for each pixel in the image, and must produce a ray-marched representation of the object. The file must have one of the following extensions: .glsl, .frag, .fragment, .glslf, .fsh. The fragment shader file is typically distributed with the dataset, and has the form $data/[dataset-name]/path/to/file.glsl.

raymarchingShader

additionalTexture

Texture file to pass to the raymarching shader as additional texture. This is usually a noise texture, but can be anything, really.

raymarchingTexture

Highlight

Defines attributes that apply to the visual representation of particle and star sets.

This component is in the following archetypes: GenericCatalog, OctreeWrapper.

Highlight attributes

Attribute

Description

Aliases

pointScaling

Scale factor taht applies to the the visual representation for each object of this dataset.