POV-Ray : Newsgroups : povray.general : Shadow density Server Time
4 Nov 2024 13:00:07 EST (-0500)
  Shadow density (Message 1 to 7 of 7)  
From: user
Subject: Shadow density
Date: 24 Oct 2008 09:55:02
Message: <web.4901d2f89d477d5ce2381b720@news.povray.org>
Hi All!

Please help me anybody slove some issue. How I do to increase hilight in
shadowed areas without increasing global hightlight?

Thanks.


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From: Thomas de Groot
Subject: Re: Shadow density
Date: 24 Oct 2008 10:40:41
Message: <4901de69@news.povray.org>
"user" <ser### [at] gmailcom> schreef in bericht 
news:web.4901d2f89d477d5ce2381b720@news.povray.org...
> Hi All!
>
> Please help me anybody slove some issue. How I do to increase hilight in
> shadowed areas without increasing global hightlight?
>
> Thanks.
>
>

Radiosity is the best answer. If you want something faster (for testing for 
instance) use an additional, shadowless light. For instance:

//start code
//main light:
light_source {
  <0, 0, 0>            // light's position (translated below)
  color rgb <1, 1, 1>*2  // light's color
  translate <-100, 10, -100>
}

//fill-in light:
light_source {
  <0, 0, 0>            // light's position (translated below)
  color rgb <1, 1, 1>*0.3  // light's color
  translate <100, 10, -100>
  shadowless
}

//end code

Thomas


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From: Dan Connelly
Subject: Re: Shadow density
Date: 24 Oct 2008 10:45:56
Message: <4901dfa4$1@news.povray.org>
user wrote:
> Hi All!
> 
> Please help me anybody slove some issue. How I do to increase hilight in
> shadowed areas without increasing global hightlight?
> 
> Thanks.
> 
> 

I don't understand the question.  You balance ambient against the strength of external
lights.  Or, if you use radiosity, you adjust the strength.

You probably want to consider radiosity.


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From: Stephen
Subject: Re: Shadow density
Date: 24 Oct 2008 12:05:24
Message: <ihs3g4hs7ttv5hhmndhv0r85b3cbjg6mdn@4ax.com>
On Fri, 24 Oct 2008 09:51:52 EDT, "user" <ser### [at] gmailcom> wrote:

>Hi All!
>
>Please help me anybody slove some issue. How I do to increase hilight in
>shadowed areas without increasing global hightlight?
>

As well as what Thomas and Dan have said, a light group might be of use if it is
just one area you want to lighten. You would use it as a "fill light" that only
affects what is in the group.

See 3.4.8  Light Groups in the help.
-- 

Regards
     Stephen


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From: Chris B
Subject: Re: Shadow density
Date: 24 Oct 2008 12:55:40
Message: <4901fe0c@news.povray.org>
"user" <ser### [at] gmailcom> wrote in message
news:web.4901d2f89d477d5ce2381b720@news.povray.org...
> Hi All!
>
> Please help me anybody slove some issue. How I do to increase hilight in
> shadowed areas without increasing global hightlight?
>
> Thanks.
>

In addition to what everyone else has already said you could:

Increase the ambient value on just the objects that the shadows are falling
on by using the ambient keyword in the finish blocks of the texture
statements for just those objects.

Add a light source in the vacinity of the objects that you wish to 
illuminate more, with a fade_distance on the light source to prevent it from 
illuminating areas further away.

And my favourite :-):
You can use two coincident copies of an object that casts a shadow, one with 
no_shadow, the other with no_image. Then you can do whatever you like with 
its shadows. You can produce partial shadows or very diffuse shadows from a 
point light source. Or you can play tricks. The example below uses a filter 
to tamper with the light as it passes through the 'no_image' copy of the 
object, saturating anything blue in the 'shadowed' area.

Regards,
Chris B.

camera {location <0,2,-4> look_at 0}
light_source {<-1,50,10>, rgb 0.4}

plane {y,0 pigment {checker}}

sphere {<0,1.5,0>,1
  no_shadow
  pigment {rgb 1}
}

sphere {<0,1.5,0>,1
  no_image
  no_reflection
  pigment {rgbf <0,0,2,1>}
}


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From: Warp
Subject: Re: Shadow density
Date: 24 Oct 2008 15:36:34
Message: <490223c2@news.povray.org>
Chris B <nom### [at] nomailcom> wrote:
> Add a light source in the vacinity of the objects that you wish to 
> illuminate more, with a fade_distance on the light source to prevent it from 
> illuminating areas further away.

http://warp.povusers.org/povtips/

-- 
                                                          - Warp


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From: user
Subject: Re: Shadow density
Date: 27 Oct 2008 06:00:00
Message: <web.49058fefb038f6fee2381b720@news.povray.org>
Thanks for all. I'm sorry that I was not post a message more datail. Hovewer you
gave me useful answers.


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