Hello 0mega42, if you know how to create and work with equirectangular projection I can help you update your codes and integrate with 2.1.
Here is a sample code for overwriting planet image;
local nauvis_pd = data.raw.planet["nauvis"].platform_surface_render_parameters.platform_backdrop
nauvis_pd.planet_surface = {
filename = "__planet-settings__/graphics/earth-day-equirectangular.png",
width = 4096,
height = 2048
}
nauvis_pd.planet_emission = {
filename = "__planet-settings__/graphics/earth-night-equirectangular.png",
width = 4096,
height = 2048
}
nauvis_pd.emission_scales_with_shadow = true
You can checkout my new mod for more fine tuning: https://mods.factorio.com/mod/planet-settings