rli### [at] everestkcnet news:412ca60c$1@news.povray.org

> from the documentation "Reflected or refracted light is not attenuated
> by distance." is this because it is computationally too expensive, or
> is this just how light works in nature?

So to summ up I suggest

1. global_settings { 
    global_light_fading on  
    global_light_distance 100 // adjust this depending on size of scene
  }

2. with #version <= 3.6 default is:  global_light_fading off

3. global_light_fading  
  a) overwrites light_source defaults to: 
    power   2  
    distance   global_light_distance
  b) make refracted rays also fade
  c) photons... are they acting as radiosity or do they also need fading? 
If they need - turn it on by default

4. defauls can be manualy overwriten ofcourse 

5. perhaps add option fade_refracted ON in light_source{} to allow manualy 
switching on/off fading of refracted ray of each light 


This will not brake old scenes 2),  it will add functionality  3.c)  and 
will make writting scene bit more comfortable  3.a) and 4)

Perhaps macros  will be usefull:
CALCULATE_LIGHT (designated_light, object_distance)  
CALCULATE_LIGHT2(designated_light, object_position, light_position)  


used as:

#local W = <200,0,0>;
#local L = <0,500,0>;
sphere { W 1 pigment { rgb 1 } }
light_source { CALCULATE_LIGHT2(0.5, W, L) }

and sphere would be have resulting color as it was lighten by 
light_source { rgb 0.5 }  no matter where we will put it.

If someone could implement this patch I can help to write manual on it and 
test it (and perhaps help coding) as I find it very usefull in creating 
photorealistick scenes (especialy togeather with radiostity and exposure)


-- 
http://www.raf256.com/3d/
Rafal Maj 'Raf256', home page - http://www.raf256.com/me/
Computer Graphics

Post a reply to this message