JD Fenech wrote:
> 
> I'm willing to attempt something.
> 
> However, my openGL experience is very limited (read: I have an idea of the
> general principle, but very little programming experience with it.)
> 
> As for Hollywood space movies: that's the last thing I want. Besides, the best
> ones of those were made before film was in color, and thus had no colored
> stars =P
> 
> Thanks for the interest,
> JD
> 

Actually, I don't think you need to know that much about OpenGL. Stars
are drawn in lighting disabled mode, which means that the color you
specify (in RGBA, values) is actually the color being drawn. i.e.,
OpenGL doesn't do any color calculations. Second, we don't use (m)any
raw OpenGL calls anymore inside FlightGear, but make use of much of the
ssg (simple scene graph) part of plib. You may wish to start reading
some of plib's documentation, which you can find at:
http://plib.sourceforge.net/ 

Note that the actual star rendering isn't done in FlightGear itself, but
in SimGear, the accompanying general purpose simulation library. Take a
look at Simgear/simgear/sky/stars.cxx. around line 228 you find
something like:

sgSetVec4( color, 1.0, 1.0, 1.0, alpha );

If you wish to make all the stars completely red, try something like 

sgSetVec4( color, 1.0, 0.5, 0.5, alpha );

and then do a

make
make install 

in SimGear and Finally a 

make

in FlightGear. 

There's more to it, e.g., if you use very low RGB values the stars get
clipped and don't show up. I haven't really figured out how this
happens. But you can play with these values a bit, to get the idea. 

B.t.w., making even minor changes in SimGear forces a complete recompile
of FlightGear. What I do mostly is to change directory to
FlightGear/src/Main and do a "make" here. This only recompiles the top
level directory and relinks the updated SimGear libs. 

B.t.w.2. This is getting pretty much a developers list topic. Maybe we
should move the conversation over to the other list. 

Regards,
Durk

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