POV-Ray : Newsgroups : povray.general : Dumb question regarding Contrast and Saturation Server Time
7 Nov 2024 15:36:37 EST (-0500)
  Dumb question regarding Contrast and Saturation (Message 1 to 7 of 7)  
From: Patrick Dugan
Subject: Dumb question regarding Contrast and Saturation
Date: 31 Jan 2002 17:17:31
Message: <3c59c27b$1@news.povray.org>
I have a few scenes which seem to be "washed out" in terms of contrast and
color saturation.
Is there any "setting" that would improve (increase) those areas?

I typically use both radiosity and photons.

My lighting and camera look like this:

#version 3.5;
global_settings {
   assumed_gamma 2.2
   max_trace_level 25

   radiosity{
      pretrace_start 0.08
      pretrace_end   0.02
      count 80
      nearest_count 5
      error_bound 1
      recursion_limit 2
      low_error_factor 0.5
      gray_threshold 0.0
      minimum_reuse 0.015
      brightness 1
      adc_bailout 0.01/2
      save_file "OutsideIn IIA.rdf"
      load_file "OutsideIn IIA.rdf"
   }

   photons {spacing 0.017 gather 100, 100 expand_thresholds 0.2, 30 autostop
0}

}

camera {
   location <0,0,-3.5>
   look_at  <0,0,0>
   rotate <-20,-10,0>

}

light_source {< -200, 200, -200> color White * 1
    photons {
      refraction on
      reflection on
      area_light
    }
}


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From: Warp
Subject: Re: Dumb question regarding Contrast and Saturation
Date: 31 Jan 2002 17:24:15
Message: <3c59c40f@news.povray.org>
When playing with radiosity you may want to play with radiosity brightness
and #default { finish { diffuse } } (ie. when you increase one you decrease
the other and the other way around). This way you can improve radiosity
lighting a lot and control better the contrast of the image.

-- 
#macro M(A,N,D,L)plane{-z,-9pigment{mandel L*9translate N color_map{[0rgb x]
[1rgb 9]}scale<D,D*3D>*1e3}rotate y*A*8}#end M(-3<1.206434.28623>70,7)M(
-1<.7438.1795>1,20)M(1<.77595.13699>30,20)M(3<.75923.07145>80,99)// - Warp -


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From: Rick [Kitty5]
Subject: Re: Dumb question regarding Contrast and Saturation
Date: 31 Jan 2002 19:38:02
Message: <3c59e36a@news.povray.org>
or you could accept the washed out look, and tweak the contrast in your
paint app of choice - probably quicker anyhow


--

Rick

Kitty5 WebDesign - http://Kitty5.com
POV-Ray News & Resources - http://Povray.co.uk
TEL : +44 (01270) 501101 - FAX : +44 (01270) 251105 - ICQ : 15776037

PGP Public Key
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From: Patrick Dugan
Subject: Re: Dumb question regarding Contrast and Saturation
Date: 31 Jan 2002 19:52:38
Message: <3c59e6d6@news.povray.org>
Well that's what I have been doing but I was hoping there was a way of
getting that same look without post processing.   You're probably right
though it's faster to just accept it and use a paint app...


"Rick [Kitty5]" <ric### [at] kitty5com> wrote in message
news:3c59e36a@news.povray.org...
> or you could accept the washed out look, and tweak the contrast in your
> paint app of choice - probably quicker anyhow
>
>
> --
>
> Rick
>
> Kitty5 WebDesign - http://Kitty5.com
> POV-Ray News & Resources - http://Povray.co.uk
> TEL : +44 (01270) 501101 - FAX : +44 (01270) 251105 - ICQ : 15776037
>
> PGP Public Key
> http://pgpkeys.mit.edu:11371/pks/lookup?op=get&search=0x231E1CEA
>
>


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From: Christopher James Huff
Subject: Re: Dumb question regarding Contrast and Saturation
Date: 31 Jan 2002 23:51:32
Message: <chrishuff-640658.23524331012002@netplex.aussie.org>
Well, I always use "#default {finish {ambient 0}}" in my scenes...no 
need for ambient light on all objects in radiosity scenes, and a fill 
light produces better results in other scenes. You could also put 
"ambient_light 0" in global_settings, but the #default method lets you 
use high-ambient objects for lighting.

-- 
Christopher James Huff <chr### [at] maccom>
POV-Ray TAG e-mail: chr### [at] tagpovrayorg
TAG web site: http://tag.povray.org/


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From: Hugo
Subject: Re: Dumb question regarding Contrast and Saturation
Date: 1 Feb 2002 03:59:10
Message: <3c5a58de$1@news.povray.org>
I want Pov to output the right contrast. This is best. Never mind the time.
But I wonder:  If I change overall diffusion, what about brilliance and
reflection ...?  They don't follow diffuse, do they?  So to make an object
really lighter or darker, without changing it's "features", one should also
modify specular, brilliance and reflection?

Hugo


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From: Christopher James Huff
Subject: Re: Dumb question regarding Contrast and Saturation
Date: 1 Feb 2002 16:42:52
Message: <chrishuff-48F00F.16440601022002@netplex.aussie.org>
In article <3c5a58de$1@news.povray.org>, "Hugo" <hua### [at] post3teledk> 
wrote:

> I want Pov to output the right contrast. This is best. Never mind the time.
> But I wonder:  If I change overall diffusion, what about brilliance and
> reflection ...?  They don't follow diffuse, do they?  So to make an object
> really lighter or darker, without changing it's "features", one should also
> modify specular, brilliance and reflection?

The brilliance keyword controls the falloff rate of the shading, and has 
nothing to do with the diffuse value, and reflection depends on the 
surroundings, whether or not to change it depends on your goal.
I'm not really sure what you're trying to do...I thought your problems 
were with overall contrast, but your message implies either you are 
trying to adjust individual objects or that you misunderstood my 
message. Did you try my suggestion of using no ambient light? My message 
didn't mention changing diffuse at all.

-- 
Christopher James Huff <chr### [at] maccom>
POV-Ray TAG e-mail: chr### [at] tagpovrayorg
TAG web site: http://tag.povray.org/


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