* Frederic Bouvier -- Wednesday 01 April 2009: > ----- "Melchior FRANZ" a écrit : > > Why would a visibility of 22 km only give me half the specularity > > of a visibility of 45 km? On an object that stands a few meters > > in front of me! That basically means, (almost) no more glossiness. > > Maybe I missed something but the visibility is not related to the > distance between the viewer and the object.
Visibility is reduced if there are lots of particles in the air (water drops, dust), and/or if there are tubulences due to heat etc. Of course, this sums up over kilometers, 10 km, 20 km, 50 km. But this sum will be very small over 20 meter in comparsion, and will barely change the glossiness of an object at near distance. And even if visibity changes from 20 km to 40 km will the glossiness not change *at all* in real life. Changes in the far reaching visibility just don't have an effect at these small distances. They will, of course, if the visibility is very close to the object distance. > As far as I understand Erik's intention, there should be no > glossiness in fog or inside a cloud, so setting glossiness to > 0 when visibility is 0 makes sense to me. Yes, *that* makes sense. But that's far from the current halving of the glossiness from 20 km to 45 km visibility. m. ------------------------------------------------------------------------------ _______________________________________________ Flightgear-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/flightgear-devel
