Kepler Translation

In order to implement a Kepler Translation, you will need to obtain the following values:

Eccentricity, SemiMajorAxis, Inclination, AscendingNode, ArgumentOfPeriapsis, MeanAnomaly, Epoch, Period (values for this example were taken from here: https://www.princeton.edu/~willman/planetary_systems/Sol/Pluto)

You will create an asset file to draw a trail, the trail will use the KeplerTranstion to decide where its points are. Once you have created the file, you will add the asset to OpenSpace.

Create an Asset File

For this example, you will create a file and put it at data/assets/keplertranslation.asset in the OpenSpace directory structure. This asset file will create a renderable trail displaying the orbit.

--keplertranslationexample.asset
local assetHelper = asset.require('util/asset_helper')
local sunTransforms = asset.require('scene/solarsystem/sun/transforms')

local PlutoKeplerTrail = {
  Identifier = "PlutoKeplerTrail",
  Parent = sunTransforms.SolarSystemBarycenter.Identifier,
  Renderable = {
    Type = "RenderableTrailOrbit",
    Translation = {
      Type = "KeplerTranslation",
      Eccentricity = 0.24883,
      SemiMajorAxis = 5906438091.0,
      Inclination = 17.14001,
      AscendingNode = 110.30,
      ArgumentOfPeriapsis = 113.76,
      MeanAnomaly = 0.003973966,
      Epoch = "2000 01 01 00:00:00",
      Period = 7821583948.8,
    },
    Color = { 0.00, 0.62, 1.00 },
    Period = 7821583948.8,
    Resolution = 86000
  },
  GUI = {
    Name = "Pluto Kepler Trail",
    Path = "/Solar System/Dwarf Planets/Pluto"
  }
}

assetHelper.registerSceneGraphNodesAndExport(asset, { PlutoKeplerTrail })

Add the Asset to OpenSpace

The final step is to simply add this asset to OpenSpace for rendering. This can be done by either:

Including the asset in a .scene file before starting OpenSpace: asset.require('keplertranslationexample')
Typing in the ` console while OpenSpace is running: openspace.asset.add('keplertranslationexample')