round particles pattern

[Espermaschine]

This is something i have been thinking over for a long time.

How to fill a selection with random little dots, like particles, all roughly the same size, but not exactly, and no overlap.

Could be used for a particle shadow like here:

   

Tried something with the G'MIC Box Fitting and Morphological (Erosion) filters.
Still not 100% to my liking.

   

[rich2005]

Maybe all or part of

1. Filter -> Render -> Clouds -> Difference Clouds
2. This is a g'mic filter Details -> Spotify with iteration & gamma values bumped up
3. Gaussian blur (3) then threshold (maybe should have used greater blur)
4. Colours -> Colourify

   

[Espermaschine]

Not bad, but i need something packed more tightly.
Yours is like snow.

BTW, what does 'Scale' mean in the G'MIC context ???
I never know what it is, or does...

[Ofnuts]

My take, which is, roughly,  1) produce nicely aligned spots, and 2) stir.

1. create a 5x5 image with a 3x3 red circle on a black background, and copy to the clipboard
   
2. create target image, fill layer with "clipboard' pattern, which shoukld give you regularly spaced red dots.
   
3. create two layers; on each:
   
   1. Filters>Render>Clouds>Solid noise, and use a fairly small details size (X&Y sliders fully to the right). For the second layer, use a new seed to make it different from the first
      
   2. Randomize the result a bit (I use "Curves"' with a big sine curve (4 wavelenghts across the width)
      
   3. Filter>Blur>Pixelize and use the size of the red dot pattern
      
4. Filters>Map>Displace map on the "dots" layer, using the other two for X and Y displacement (2px for the pattern size I used)
   

   

With attached XCF.GZ, and the Curves setting I used to randomize the SolidNoise output (add at the end of your .gimp-2.8/tool-options/gimp-curves-tool.settings)

[Espermaschine]

^
Wow !

Would have never thought of using a displacement map.

EDIT: the import of the curves does not work for me. I can import the txt file but nothing happens curves-wise...
same with putting it in the curves folder, or removing the .txt ending...