TimelineTranslation

Inherits Translation

Members

Name	Documentation	Type	Description	Optional
Keyframes	A table of keyframes, with keys formatted as YYYY-MM-DDTHH:MM:SS and values that are valid Translation objects	Table	Table parameters	No
ShouldInterpolate	If this value is set to ‘true’, an interpolation is applied between the given keyframes. If this value is set to ‘false’, the interpolation is not applied	Boolean	Value of type ‘Boolean’	Yes

Inherited members from Translation

Name	Documentation	Type	Description	Optional
Type	The type of translation that is described in this element. The available types of translations depend on the configuration of the application and can be written to disk on application startup into the FactoryDocumentation	String	Must name a valid Translation type	No

Table parameters for Keyframes

A table of keyframes, with keys formatted as YYYY-MM-DDTHH:MM:SS and values that are valid Translation objects

• Optional: No

Name	Documentation	Type	Description	Optional
*		Table	Translation	No

Asset Examples

local earthTransforms = asset.require("scene/solarsystem/planets/earth/transforms")
local sunTransforms = asset.require("scene/solarsystem/sun/transforms")
local l2 = asset.require("scene/solarsystem/planets/earth/lagrange_points/l2")
local kernels = asset.require("./kernels")
local coreKernels = asset.require("spice/core")



local LaunchTime = "2021 DEC 25 12:20:00"
local DetachTime = "2021 DEC 25 12:50:00"
local L2orbitInsertionTime = "2022 JAN 25 00:00:00"

local JWSTPosition = {
  Identifier = "JWSTPosition",
  Parent = earthTransforms.EarthIAU.Identifier,
  Transform = {
    Translation = {
      Type = "TimelineTranslation",
      ShouldInterpolate = false,
      Keyframes = {
        [LaunchTime] = {
          Type = "SpiceTranslation",
          Target = kernels.ID.JWST,
          Observer = coreKernels.ID.Earth,
          Frame = coreKernels.Frame.Earth
        },
        [DetachTime] = {
          Type = "SpiceTranslation",
          Target = kernels.ID.JWST,
          Observer = coreKernels.ID.Earth,
          Frame = coreKernels.Frame.Galactic
        },
        [L2orbitInsertionTime] = {
          Type = "SpiceTranslation",
          Target = kernels.ID.JWST,
          Observer = l2.ID.L2,
          Frame = coreKernels.Frame.Galactic
        }
      }
    }
  },
  GUI = {
    Name = "JWST Position",
    Path = "/Solar System/Telescopes/JWST",
    Hidden = true
  }
}

local JWSTRotation = {
  Identifier = "JWSTRotation",
  Parent = JWSTPosition.Identifier,
  Transform = {
    Rotation = {
      Type = "FixedRotation",
      Attached = "JWSTRotation",
      XAxis = { 1, 0, 0 },
      XAxisOrthogonal = true,
      YAxisInvert = true,
      YAxis = sunTransforms.SolarSystemBarycenter.Identifier
    }
  },
  GUI = {
    Name = "JWST Rotation",
    Path = "/Solar System/Telescopes/JWST",
    Hidden = true
  }
}


-- Reparent the JWSTPosition node when the data changes
asset.onInitialize(function()
  openspace.addSceneGraphNode(JWSTPosition)
  openspace.addSceneGraphNode(JWSTRotation)

  -- Set correct parent during run-time
  openspace.scriptScheduler.loadScheduledScript(
    DetachTime,
    [[openspace.setParent("JWSTPosition", "EarthCenter")]],
    [[openspace.setParent("JWSTPosition", "EarthIAU")]],
    "",
    1 -- Not default group, never clear this script
  )
  openspace.scriptScheduler.loadScheduledScript(
    L2orbitInsertionTime,
    [[openspace.setParent("JWSTPosition", "L2")]],
    [[openspace.setParent("JWSTPosition", "EarthCenter")]],
    "",
    1 -- Not default group, never clear this script
  )

  -- Set correct parent at the start
  local now = openspace.time.currentTime()
  if now < openspace.time.convertTime(DetachTime) then
    openspace.setParent("JWSTPosition", "EarthIAU")
  elseif now > openspace.time.convertTime(L2orbitInsertionTime) then
    openspace.setParent("JWSTPosition", "L2")
  else
    openspace.setParent("JWSTPosition", "EarthCenter")
  end
end)

asset.onDeinitialize(function()
  openspace.removeSceneGraphNode(JWSTRotation)
  openspace.removeSceneGraphNode(JWSTPosition)
  openspace.scriptScheduler.clear(1)
end)

asset.export(JWSTPosition)
asset.export(JWSTRotation)



asset.meta = {
  Name = "James Webb Space Telescope Transforms",
  Version = "1.0",
  Description = [[
    JWST transforms: JWST position relative to Earth and JWST rotation,
    a fixed rotation so sunshield always points toward the Sun.
  ]],
  Author = "OpenSpace Team",
  URL = "http://openspaceproject.com",
  License = "MIT license"
}