ENH: Colormap Tracks by Variable

[KCollins]

Description

Similar to magnetosphere asset: have a drop down to be able to color-code path by ocean variables (salinity, e.g.)

https://www.gosud.org/Data-access/Products

Potential impact

Useful for model/data comparisons.

Approach

See how the magnetosphere asset does it (click below):

[KCollins]

Ok, here's how the magnetosphere asset does it:

local transforms = asset.require("scene/solarsystem/planets/earth/transforms_gsm_static")



local transferFunction = asset.resource("CMR-illuminance2.txt")

local fieldlinesDirectory = asset.resource({
  Name = "Magnetosphere 2012 event",
  Type = "HttpSynchronization",
  Identifier = "magnetosphere_2012_event",
  Version = 1
})

local EarthMagnetosphere = {
  Identifier = "EarthMagnetosphere",
  Parent = transforms.GeocentricSolarMagnetosphericStatic.Identifier,
  InteractionSphere = 6380000,  -- A value slightly bigger than earth radius
  Renderable = {
    Type = "RenderableFieldlinesSequence",
    SourceFolder = fieldlinesDirectory,
    LineWidth = 1.0,
    ShowAtAllTimes = true,
    AlphaBlendlingEnabled = false,
    InputFileType = "Osfls",    -- OpenSpace Field lines sequence
    MaskingEnabled = true,
    MaskingQuantity = 5,      -- corresponds to "topology"
    MaskingRanges = { { -0, 0 } },  --closed only
    ColorMethod = "By Quantity",
    ColorQuantity = 4, -- speed
    ColorTableRanges = { { 50, 300 } },
    LoadAtRuntime = true,
    ColorTablePaths = { transferFunction },
    ScaleToMeters = 1.0,
    Color = { 1.0, 0.725, 0.75, 0.8 }
  },
  GUI = {
    Path = "/Solar System/Planets/Earth",
    Name = "Magnetosphere"
  }
}


asset.onInitialize(function()
  openspace.addSceneGraphNode(EarthMagnetosphere)
end)

asset.onDeinitialize(function()
  openspace.removeSceneGraphNode(EarthMagnetosphere)
end)

asset.export(EarthMagnetosphere)

asset.meta = {
  Name = "Static generic magnetosphere of fieldlines",
  Description = "Generic static magnetosphere fieldlines. Actual timestep 2012-07-14T00-00-00-000. Defaultly colored by speed; 50-300 km/s",
  Author = "CCMC",
  URL = "",
  License = "CC-BY"
}

Contents of CMR_illuminance2.txt:

width 10
lower 0.0
upper 1.0

mappingkey  0.0     60   38    164  255
mappingkey  0.083   106  43    167  255
mappingkey  0.166   173  54    110  255
mappingkey  0.332   253  64    40   255
mappingkey  0.415   234  117   6    255
mappingkey  0.498   230  169   16   255
mappingkey  0.664   236  236   159  255
mappingkey  0.830   251  251   235  255
mappingkey  0.915   255  255   255  255
mappingkey  1.0     255  255   255  255