Lee Qid wrtote > > Hi there, > > let me join this discussion: > > Very good summary indeed. Pretty much what I was just writing. > If you want to get a feel of specular highlights, look at car-paint, > and observe what is reflected on the metal that actually causes the > highlights. You will find that it is the sun, street-lights or lit > billboards. Basically anything emitting a lot of light. > As for causastics, I'd say that you add the it to the ambience. You > could try and sum up and average the diffuse colours of the scenery > tiles every once in a while to get the causastic part for the ambient > colour, if you like. > > You may also want to look at your fog implementation. It may yield a > clue on how to determine the amount of light passing through depending > on the altitude of the object and density of the fog. You can also try > to modify the size and brightness of the highlight, depending on the > cloud cover _above_ the object (overcast <-> clear). >
What I take from this discussion so far is that the modeller should determine the diffuse colour of a material and its shininess. The modeller should normally set the ambient and specular colours to be the same as the diffuse colour, unless it's an odd material. FlightGear should adjust the ambient, diffuse and specular colours according to the incident light intensity, amount and type of scattering etc. In direct sunlight diffuse colour should be slightly yellow, while ambient colour should be slightly blue. Specular highlights should shade towards the colour of the incident light. Where the lighting is almost all ambient, fog or cloud, there should be no specular reflection, and the ambient colour should be a (light) grey shade. I'm not clear about how much ambient light there should be in any situation, but, to me right now there isn't enough with the default model. The effect of visibility on the diffuse and specular setting looks OK in very low visibility, but at high visibility it looks very odd - far too little ambient, while at medium visibility specular refection is too low. I think that outside the fog situation the visibility should have little or no effect on diffuse or specular values. I look forward to seeing if a log relationship is better. And we need shadows to complete the effect! Vivian ------------------------------------------------------------------------------ _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
