It's very cool that you got a 5 million star catalog working--how fast did Celestia run? The octree visibility culling algorithm used by Celestia should scale very well, but I haven't tried it myself.
It run at (approximately) 10-2 fps (depended on the amount of stars visible)
I think it could run much faster when I introduce more different star sizes (result: more culling, less visible stars)
If I have understood the concept of an octree, it would be possible to calculate for each of the "branches" a brighness value, so that it could be rendered as a nebulous object from large distances.
btw, all the screenshots I made were taken with a very wide fov, so that i could zoom in to the galaxy close enough that the stras in the back didn't disappear. If you watch these stars on normal settings from some thousand light years, you see absolutely nothing.
The "color" calculated from the star types and brightness in an octree branch could be a soultion, but as I said, I need to familiarize myself with the code to see if that's possible.
@Chris: Yes, I meant that :-) In the catalog there are only obscure numbers around 800 or 1400, (showed my Hex-Editor)
@chris (2nd time): we could use the galaxy definition file for random star distribution, put it in the code and make it switchable so that users can switch the irreal stars off.
You'd have to add an algorithm, though, that removes all irreal stars visible from earth (we have stars there already :-)
I'll come back Sunday evening (Middle European Time :-)
Sirius
Wow...If you add Chris's galactic nebula formation model that would look even more realistic...
.
