Thomas de Groot nous apporta ses lumieres en ce 2007/11/05 03:47:
> "alphaQuad" <alp### [at] earthlinknet> schreef in bericht 
> news:web.472e20902a06dfe95b922c2d0@news.povray.org...
>> "alphaQuad" <alp### [at] earthlinknet> wrote:
>>> dont think I got the hang of it yet
>>
>> here's a curiosity: what can POV do?
>>
>> what about a half moon in the middle of the day?
>>
> 
> This has been solved very nicely by Bill Pragnell (look for a message  dated 
> november 23, 2005, I think in this same ng) and I have used the trick in 
> several of my scenes. I took some notes which I reproduce here:
> 
> 1) use a hollow sphere around your scene (or use inverse) set background to 
> black
> 2) give it the required color gradient you would give a sky_sphere, but use 
> a partial transparency, ambient 1, diffuse 0
> 3) put the moon and the light source (sun) outside of this sphere: the parts 
> in shadow will have the same color as the local sky
> 4) if you want to use radiosity: use an interior_texture on your sphere. The 
> ouside texture should be rgb 0, with transmit=1
> 
> note 1: you may have to experiment a bit with the transparency and/or the 
> gradient colors to get the desired effect.
> note 2: instead of a sphere, you can use other objects of course: a plane or 
> a cube or whatever.
> 
> Hope this helps
> 
> Thomas
> 
> 
Additional note: the sphere center don't need to be at the camera location or on 
the ground. A more realistic result can be done with a flatened sphere with it's 
center moved down like: (good for you clouds)
sphere{0,10000 scale<1,0.5,1>translate -2500*y texture{...}}

-- 
Alain
-------------------------------------------------
   I know I'm not sexy. When I put my underwear on I can hear the Fruit- 
of-the-Loom guys giggling.
	Rodney Dangerfield

Post a reply to this message