I was reading this tutorial on procedurally generating galaxies, and while all the pictures show the galaxy made of dots, the last picture shows the colored nebula, but the tutorial doesn't explain how that's done. Would it be a shader effect? Either way I'd love to know how it can be done.

39 minutes ago, Master thief said:

the last picture shows the colored nebula, but the tutorial doesn't explain how that's done

That seems to be a screen shot from Spore.

40 minutes ago, Master thief said:

Would it be a shader effect?

Maybe. My guess is it's just a bunch of additively-blended sprites though.

Typically you'd lake a low-intensity texture that looks a bit like a cloud, and render a bunch of them with additive blending enabled. That'll give you the cloudy halo. Then render a bunch of bright points over the top to look like individual stars.

It could also be some sort of post-process bloom filter being applied to a bunch of points.

On a side note, if you're interested in creating more physically accurate spiral galaxies, search up these two terms in relation to how stars orbit the galactic centre:

Density Wave Theory

Rotation Curve