In article <44a46aca$1@news.povray.org>, ele### [at] netscapenet 
says...
> Patrick Elliott nous apporta ses lumieres en ce 29/06/2006 16:22:
> 
> > Anyway.. I seem to remember discussions of problems with trying to 
> > simulate sunlight, etc. Mainly, no matter how far away you place a 
> > light, it never produces a parallel path, or at least not without 
> > placing it so far away that the light never gets to the objects. But, i
f 
> > I understand Sky_Sphere right, it acts on the color of a pixel if the
 
> > ray goes effectively infinite.. So, my first thought was something like
:
> > 
> > Sky_Light {
> >   X, Y, Z
> >   // 0 = point light, 1 = unit disc.
> >   size {0/1
> >         [scale <x,y>]}
> >   pigment {...}
> >   falloff 0->1
> > }
> > 
> > Where X,Y,Z is the "direction" from origin the light would appear on th
e 
> > sky_sphere, size is either a point or unit sized disc, which in the 
> > later case can be scaled, and there is a falloff, which lets you 
> > determine how fast the light shrinks. The only problem was.. How to mak
e 
> > it work with the sky_spheres own pattern, so I thought:
> > 
> > Sky_Light {
> >   X, Y, Z
> >   // 0 = point light, 1 = unit disc.
> >   size {0/1
> >         [scale <x,y>]}
> >   pigment {...}
> >   [mask_pattern {...}]
> >   falloff 0->1
> > }
> > 
> Why don't you use parallel in the light's description? It makes all the r
ays of light effectively 
> parallel, thus simulating a light source that is situated at "infinity".
> light_source{Location, Colour parallel point_at PointAt}
> 
Umm. Other than not realizing that existed... lol Still, you might be 
able to do a lot more with my concept, for example, a point source is a) 
not an accurate presentation of the sun, b) not sized right and c) 
doesn't add any light from the sky itself. What I was thinking in terms 
of was a light that could be made to have a bright center, a quick fall 
off near its edge, but the rest of the sky still "bright" from it, 
though faded towards the far edges of the horizon. The theory being that 
for some cases, this might give more control over what it actually 
produces. As things currently stand, any light will tend to effect a 
sky_sphere more or less equally across its entire surface, which it 
seems to me isn't quite right.

Anyway, it was just an idea. I think it could be used to do some 
interesting stuff, maybe.

-- 
void main () {

    call functional_code()
  else
    call crash_windows();
}

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