I'm working on an alien planet design in Photoshop, and I'm wondering if there are any brushes or techniques for easily creating that "city lights from space" effect? I'm hoping to create a randomized field that I can apply to various images, mimicking the clusters (i.e. big cities), smaller lights (i.e. towns), and lines (i.e. roads) to create a convincing sense of civilization.

enter image description here

It doesn't need to conform to any coastlines, etc, as I can handle that later with masks. Just a black background with grayscale pinpoints, following this type of structure, in a random pattern.

Ideally, it would be easy enough to produce that I could crank out several versions quickly, and the pinpoints would be of varying lightness so that I could filter by a luma value (e.g. "everything above 50% lightness") to simulate varying levels of population density on the same landscape (i.e. "here's a planet barely colonized, and here's that same planet densely colonized").

Does a system like that exist?

  • 1
    Filter > Noise > Add Noiseon a white layer then invert.
    – Scott
    Aug 14, 2015 at 21:01
  • 2
    I feel like you could do something like that by creating a brush similar to the one in this answer: graphicdesign.stackexchange.com/a/37521/2332 and maybe another circle brush with like scatter and size jitter ( for the slightly more visible dots ). Then just brush away.. You could perhaps do it slightly more automatically, but to me brushing in the lights manually sounds like a viable idea.
    – Joonas
    Aug 14, 2015 at 21:17
  • 1
    As your question seems to be more about modelling population densities than about the actual visualisation, you might get a better answer at Worldbuilding. Moreover I want to note that I do not think you can see any road on your example image (just settlements lining up along roads) and that I do not think you can handle coastlines with masking as there is an increase of population near them which can be clearly seen in your example image.
    – Wrzlprmft
    Aug 14, 2015 at 21:26
  • @Wrzlprmft My question is not at all about modeling population densities, it's about making an effect for a photoshop project. I don't care about statistics and such, beyond just making the effect realistic. And yes, "settlements lining up along roads" it obviously what I meant by "roads". No 30ft-wide stretch of concrete is going to be visible in an image like that.
    – Nerrolken
    Aug 14, 2015 at 22:23
  • 1
    Run the filter on multiple layers... resize, merge, repeat. Google will show you hundreds of tutorials on creating "star fields". That's essentially what you are asking for.
    – Scott
    Aug 14, 2015 at 23:30


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