Erik Hofman <[EMAIL PROTECTED]> said: > Take a look at this screenshot. The shaded part of the aircraft (and > buildings but thats hard to see) is much too bright. It's almost like it > is about four our earlier (and very foggy): > > > http://www.a1.nl/~ehofman/fgfs/download/f104-dawn.jpg > > What I'm trying to do now is get every lighting state to a completely > sunny day with almost unlimited visibility. From there the state should > be adjusted based on visibility, number of cloud layers and cloud types. > > That would be much easier to start with. >
Well just don't throw the cockpit out, that's part of the scene too. That particular time of day, the light changes really fast, possibly much faster than we're doing it. Here's a couple of screenshots from that other simulator. Their lighting seems pretty good, btw: http://www.microsoft.com/games/flightsimulator/img/screens1/ss4.jpg http://www.microsoft.com/games/flightsimulator/img/screens1/ss15.jpg It looks like, given the position of the sun, your screenshot is too dark overall. The sun is actually well above the horizon and probably a degree or two higher than the first msfs example, but ours is still quite a bit darker. In general all times of day appear too dark on my display now. Making the lighting brighter would provide more contrast against the ambient levels as well. In any case I'm open to suggestions on how we can do better lighting of the cockpit. With the lower ambient light levels the cockpit always appears way too dark except when the sun is directly behind. Lighting and shading is tricky because of the way that the human iris and brain adjusts for different levels. Late day photographs always appear to have darker shaded sides than "realistic", unless the photographer has taken care to slightly overexpose the image. For this reason, matching to photographs won't give you a more realistic appearance, but a more photograph like appearance. True ambient light levels are due to reflections of light off other surfaces, but ambient lighting in opengl is useful for lightening the dark side so that it appears more like the real thing. At dawn the dark side of buildings contrasts to the bright sunlit sides, but you can still actually see the color of the buildings quite clearly. If you are standing with the sun in your eyes however, the shaded sides will appear very dark at the same time of day. But representing this effect on a screen is quite complex. Consider that facing the sun, the dark side of the building will appear to get lighter if the human viewer focuses on the dark areas, or blocks the sun itself with a hand or visor, or the sun temporarily falls behind a pillar in the aircraft. That is why I took the approach of setting the ambient lighting high enough to make dark sides (and the cockpit) visible, while leaving enough contrast in there to give the terrain some depth. The values probably could be tweaked, especially with the recent changes in lighting, but inevitably we'll be looking at tradeoffs. Best, Jim _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
