Re: [Flightgear-devel] Moonlight

[Thorsten R. <tho...@sc...>]

> Still, this is not to be confused with a subjective phenomenon.

I don't think anyone said 'subjective phenomenon' - the word used was  
'perception'.

> But I really
> still do not at all understand the argument for shifting this into
> FGData!

Because ALS has what you call 'eye physics' and I 'perception' pulled  
inside the GLSL code whereas Classic and Rembrandt do not (the difference  
is for instance in how light from different sources is added).

  Especially if this is later used to create a new (or
> replacement) OSG light source, where it needs to be on the c++ side
> where the scene graph is set up.

ALS is ultimately going to do the same which it does with the sun light  
source for the same reasons (attenuation and perception are computed  
inside the GLSL code): take the position info and discard the color info.



> I'll try to nevertheless create a set of system tests to ensure that
> Durk's code, Curt's code, and my small additions will work as expected
> for the lifetime of the FlightGear project.  If I can set up exact
> starting conditions where the /sim/time/moon-angle-rad value is
> exactly 0, pi/2, etc., then this will be very easy to debug and fix.

Look, move the moon rendered in FG towards the horizon. That's not  
complicated to do - you find it in the sky and just fast-forward/backward  
time till it's there.

Anyway, I don't get the impression you're taking this as a bug report, but  
I can't work with the moonlight info as it comes out of the code now and  
trying in vain to convince you that there's a need for action or fiddling  
with code you believe is correct is not a good use of my time. I'll do an  
ad-hoc fix of all the issues using property rules, and you can test your  
code at your leisure.

* Thorsten