[Flightgear-devel] Nightsky

[Renk T. <tho...@jy...>]

I've been making some progress with rendering from orbit

http://users.jyu.fi/~trenk/pics/earthview_new12.jpg

but I'm still trying to wrap my head around what the sky does. Is there anyone who understands what I am seeing?

My Windows binary of ~ a month ago shows the skydome below 310.000 ft or so, then exits it and I see fog-grey. Then comes a zone of red sky (which is a rendering artefact caused by the lack of atmosphere definition, the added layer patch is not yet in this binary) but up at 1.000.000 ft, I actually get to see black skies and even sometimes stars come out when the sun is below the horizon(!).

My Linux binary of 3 days ago shows fog grey all the way up from 310.000 ft to as far as I tested - no red (as expected since this was fixed), but also no black and no stars.

So there is a beautiful starry sky implemented somewhere, and it'd be nice to just use it. Does anyone understand what precisely we render at high altitude and where the starry sky comes from, and can we somehow always render it above 300.000 ft?

Alternatively I could give Earthview its own star sphere (to be textured freely...), but then that might hide sun and moon from the view, I don't recall where they are physically located, and having a working moon in the sky is definitely a nice feature.

I realize that this is a bit of an exotic use of FG and probably not so many people want to do spaceflight, but if there's a simple way to get a nice night sky at high altitude, I would much appreciate some help.

* Thorsten