On Saturday 02 August 2003 15:23, Curtis L. Olson wrote: > Erik Hofman writes: > > Curtis L. Olson wrote: > > > Erik Hofman writes: > > > > > >> > > >>Hi, > > >> > > >>I've updated the lighting to reflect the following: > > >> > > >>scene_ambient = fog_color * ambient > > >>scene_diffuse = fog_color * diffuse > > >>scene_specular = sun_color * specular > > >> > > >>As I said, this is still just a test, but I like to know every bodies > > >>opinion so far. > > > > > > > > > Why? This doesn't seem right to me? Is there some basis in reality > > > for this change? > > > > What does seem right to you? > > Surely not the way it was before ... > > Fog color is determined by a lookup table based on sun angle. > > Scene lighting is also determined by a lookup table based on sun > angle. > > If you multiply those, you'll end up with the sun angle being factored > in twice. > > Also, if our terrain textures are taken from photos, they will already > have proper sun illumination factored in. > > Could you explain what you think is lacking and why you think this > will help? Maybe I'm missing something? > > Curt. > -- > Curtis Olson IVLab / HumanFIRST Program FlightGear Project > Twin Cities curt 'at' me.umn.edu curt 'at' flightgear.org > Minnesota http://www.menet.umn.edu/~curt http://www.flightgear.org
Is specular here referring to the specular high-light colour? Specular colour, in that sense, as i understand it, is going to be dependent upon the colour of the direct light source and the colour of the object that filters it, so it makes some sense to me that the sun (or moon) colour figures into specular. I'm not sure about the distinction between ambient and diffuse here. I'd say that ambient should be everything minus direct - basically white minus the sun colour, and I'd guess that diffuse should be a combination of the two with a bias towards the direct colour as this is second order reflected light, much like the sort of light you get on an overcast day (you actually get more accurate colours in photgraphy in an overcast than in sunlight). Anyway, in practice it's difficult to assess true colours as our eyes, or minds rather, do a pretty good job of correcting the the colours - for example we don't easily detect the colour casts from either incandescent or flourescent lighting with our eyes but it's very apparent in a photgraph - hence specific films for daylight, incandescent and flourescent lighting. Working something out for FG will be a tricky because it won't look right unless you match the brains interpretation of the colours, which as I said, is 'normalised' and not accurate. LeeE _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
