

Is this your work? I really like your visual results, congratulations!
I would like to piggyback your post to share my attempt at the same problem, if you don’t mind. I used one sprite with one shader for each celestial body, no viewports, but also no shadows.
https://git.fabioiotti.com/bruce965/space-capture






Adjusting the weights is how training works.
If you are thinking about adjusting the number of weights, that’s also a technique. The issue is that (afaik) it can only be trained through genetic algorithms, which take longer than backpropagation.
(This information might be incomplete/incorrect.)