Global city lights.

[bigben]

Looking back through some of my old posts I found this: http://www.planetside.co.uk/forums/index.php/topic,2686.0.html  (Note to self... Check if vector data from OSM can be used for "lower altitude stuff)  I also had a clip of my subsequent lighting setup and here is a file with my global lights setup.  It includes a couple of low res image masks.  These can be switched with higher res images of your own.

Apart from providing some control over the intensity and distribution of the lights it also breaks the mask image up into small circles so the it looks a little more like lights rather than large areas of illuminated surface.

Key nodes:

• Luminosity amount: Dimmer switch for the lights. 0.5-1 are visible from space. Up to 20 will light clouds from below.
• 
  Adjust Lights image 1: Colour adjust node that can tweak the distribution of the lights.  Decreasing the gamma will accentuate the variation between dim and bright regions of lights. Increasing black level will turn off dimmer areas.
• Sun position group should have the same settings as the sun's position, and Planet center = the planet's center
  
• To allow lights over bodies of water (e.g. oil rigs) bypass the water mask by connecting Voronoi billows to circles to the input of Mask by angle from sun (I'll be releasing higher res versions of my water mask later)
  
• Demo angle range mask sets the boundary between light off/lights on in relation to the sun's position

Enjoy

[bigben]

I've been using the black marble 2012 image previously. Will have to update this to the 2017 version.  https://earthobservatory.nasa.gov/Features/NightLights/page3.php  Fortunately available as GEOTIFF this time

[Dune]

Very cool of you to share, Ben. Thanks so much!

[bigben]

You're welcome.  Here's a test render with a 36K version of the 2016 city lights image. Luminance cranked up to 20. Cloud base at 1km.  The global cloud shader is new to me so I still have some new settings to get my head around.  I had to increase the density to get the clouds to show up a bit more on the night side. Maybe some tweaks to the lighting settings as well. Might end up with a duplicate cloud layer with one setting for the day side and one for the night.

[Ariel DK]

Nice stuff Ben, for your global clouds, try to set
- ambient to 0.02
in the lighting tab:
- light propagation to 0
- propagation mix to 0.1
- fake scatering to 4
- uncheck "Darker unresolve scattering"
- and decrease density to 0.005

That must to work for day and night side (or at least it's a begin)
is better to try with two clouds layer, and large render times

[bigben]

Thanks. I'll give those a try. 

[Oshyan]

Excellent, thanks for sharing! But might I suggest putting your notes and suggestions for use into a text file in the zip as well? I haven't looked at the TGD yet so it might already be in note nodes, so ignore me if so.

- Oshyan

[bigben]

Yes, text file in the ZIP is probably a good idea too.

...
- and decrease density to 0.005

This one I'm not so sure about.  The main tweak I had to do previously was increase the density. At very low densities the clouds disappear in shadows

[Ariel DK]

But they disappear completely? The clouds are more brighter now, so you dont want to lost some details in the day side.
also is good remember that doesn't exist a completely DARK side of the earth. in my scene, the city lights provide enough
light to the clouds, but Im also using an aditional source light (moon bright), and even so, is necessary increase just a little
bit the camera exposition (as in real life) to see every detail