HI!

I'm trying to create a little omnidirectional light only for closer objects
and I try with:

light_source {< 0, 0,  0> color White
   fade_distance 0 fade_power 0
   area_light <0.1, 0, 0>, <0, 0, 0.1>, 3, 3
}

but this light up all the objects in the scene!!

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"danyolgiax" <d.o### [at] gmailcom> wrote:
> HI!
>
> I'm trying to create a little omnidirectional light only for closer objects
> and I try with:
>
> light_source {< 0, 0,  0> color White
>    fade_distance 0 fade_power 0
>    area_light <0.1, 0, 0>, <0, 0, 0.1>, 3, 3
> }
>
> but this light up all the objects in the scene!!

You want either spotlights or cylindrical lights (most likely sptolights,
see: 3.4.7.2  Spotlights in the docs). Area lights are essentially just an
array of point lights so are not omni directional (unless you build a shade
around them, which is another option, depending on your needs)

-tgq

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news:web.4443afe8538e3be258dbbb6b0@news.povray.org...
> HI!
>
> I'm trying to create a little omnidirectional light only for closer
objects
> and I try with:
>
> light_source {< 0, 0,  0> color White
>    fade_distance 0 fade_power 0
>    area_light <0.1, 0, 0>, <0, 0, 0.1>, 3, 3
> }
>
> but this light up all the objects in the scene!!

The more realistic setting (for a close light) for fade_power is 2 (i.e.
fading with the square of distance)
fade_distance depends on the scale of your scene but I still let it at
default value

Marc

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danyolgiax <d.o### [at] gmailcom> wrote:
>    fade_distance 0 fade_power 0

  Well, fade_power 0 means that the light doesn't fade. Logical.

-- 
                                                          - Warp

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danyolgiax nous apporta ses lumieres en ce 17/04/2006 11:10:
> HI!
> 
> I'm trying to create a little omnidirectional light only for closer objects
> and I try with:
> 
> light_source {< 0, 0,  0> color White
>    fade_distance 0 fade_power 0
>    area_light <0.1, 0, 0>, <0, 0, 0.1>, 3, 3
> }
> 
> but this light up all the objects in the scene!!
> 
> 
> 
> 
fade_power 0 means NO fading. It's the default value.
fade_distance 0 don't make any sense. Try a small to very small,but non-zero, value.
Best bet: fade_power 2 fade_distance 0.1 (or less) and increase the brightness of the
light as much 
as needed, like 100 to 10000.
You can use a fade_power larger than 2, like 3 or 4 or even more.
You can also use a light_group where you link the closer objects with your light. Add
"global_lights 
on" if you want it to also be lighted by other light.

-- 
Alain
-------------------------------------------------
Christian Science: Shit happening is all in your mind.

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"Trevor G Quayle" <Tin### [at] hotmailcom> wrote:
> "danyolgiax" <d.o### [at] gmailcom> wrote:
> > HI!
> >
> > I'm trying to create a little omnidirectional light only for closer objects
> > and I try with:
> >
> > light_source {< 0, 0,  0> color White
> >    fade_distance 0 fade_power 0
> >    area_light <0.1, 0, 0>, <0, 0, 0.1>, 3, 3
> > }
> >
> > but this light up all the objects in the scene!!
>
> You want either spotlights or cylindrical lights (most likely sptolights,
> see: 3.4.7.2  Spotlights in the docs). Area lights are essentially just an
> array of point lights so are not omni directional (unless you build a shade
> around them, which is another option, depending on your needs)
>
> -tgq

oops, I think I misread everything here (and mixed up my omni/uni
directionals) ignore my comments!

As the others said play with fade_distance/fade_power and/or light groups.

See "3.4.7.9  Light Fading" and have a look at the function and how the the
variables affect the fading response.
-tgq

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