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From: Ken
Subject: Media and Opposite Colors
Date: 27 Sep 1999 22:00:59
Message: <37F020F8.D16F95EC@pacbell.net>
How does one calculate an opposite color for use in absorbing and
emitting media ?

  Advanced user question ?

-- 
Ken Tyler
1100+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html


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From: TonyB
Subject: Re: Media and Opposite Colors
Date: 27 Sep 1999 23:08:07
Message: <37f03117@news.povray.org>
(1 - OriginalColor)    ?


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From: Ken
Subject: Re: Media and Opposite Colors
Date: 28 Sep 1999 00:36:34
Message: <37F0456B.8467E790@pacbell.net>
TonyB wrote:
> 
> (1 - OriginalColor)    ?

Won't work...

rgb<1,0,0> - rgb<1,0,0> = black.

The opposite of red is not black at least so I suspect.

-- 
Ken Tyler
1100+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html


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From: Ron Parker
Subject: Re: Media and Opposite Colors
Date: 28 Sep 1999 00:38:53
Message: <slrn7v00cq.32p.parkerr@linux.parkerr.fwi.com>
On Mon, 27 Sep 1999 21:34:51 -0700, Ken <tyl### [at] pacbellnet> wrote:
>
>
>TonyB wrote:
>> 
>> (1 - OriginalColor)    ?
>
>Won't work...
>
>rgb<1,0,0> - rgb<1,0,0> = black.

1 is not rgb <1,0,0>; I'm pretty sure it's rgbft <1,1,1,1,1>.
You want rgb <1,1,1> - OriginalColor.


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From: Ken
Subject: Re: Media and Opposite Colors
Date: 28 Sep 1999 00:41:53
Message: <37F046AB.651C076F@pacbell.net>
Ron Parker wrote:

> You want rgb <1,1,1> - OriginalColor.

so -

rgb<1,1,1> - rgb<1,0,0> = rgb <0,1,1> = opposite color ?

-- 
Ken Tyler
1100+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html


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From: Ron Parker
Subject: Re: Media and Opposite Colors
Date: 28 Sep 1999 00:42:34
Message: <slrn7v00jm.32p.parkerr@linux.parkerr.fwi.com>
On Mon, 27 Sep 1999 21:40:11 -0700, Ken <tyl### [at] pacbellnet> wrote:
>
>
>Ron Parker wrote:
>
>> You want rgb <1,1,1> - OriginalColor.
>
>so -
>
>rgb<1,1,1> - rgb<1,0,0> = rgb <0,1,1> = opposite color ?

Exactly.

Cyan is the opposite of red.


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From: Ken
Subject: Re: Media and Opposite Colors
Date: 28 Sep 1999 00:44:07
Message: <37F04732.87C5DD95@pacbell.net>
Ron Parker wrote:

> Cyan is the opposite of red.

Cyan = opposite of red = ok fine by me.

Thank you for your assistance gentlemen.

-- 
Ken Tyler
1100+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html


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From: Bob Hughes
Subject: Re: Media and Opposite Colors
Date: 28 Sep 1999 00:46:48
Message: <37f04838@news.povray.org>
I was trying this out to do it an easy way and stumbled into errors
concerning the color vector, int( ) and #if ( ). It would be fine were
it not for the negative vector created when switching back to original
color.  I didn't know vectors weren't allowed in these (and whatever
else there might be too).

// white pointlight at camera position
#declare LCX = 0;
#declare LCY = 0;
#declare LCZ = -10;

light_source { <LCX,LCY,LCZ> color rgb <1.5,1.5,1.5>
}
camera {
  location  <LCX,LCY,LCZ>
  angle 30
  look_at   <0,0,0>
}

// zero or 1 (more than 1 not acceptable)
#declare EAF=0;
// original color to calc opposite of
#declare OC=.5; // <.1,.3,.9>;  vector does not go into int( )
// opposite color vector (or not) [int(EAF-OC) errors wanting float
only]
#declare RGB=EAF-OC;
 // convert to positive if negative [#if (RGB errors wanting float)]
 #if (RGB<0) #declare RGB=-1*RGB; #end

box {-1,1 pigment {color rgb RGB} rotate <30,45,60>}

Bob

TonyB <ben### [at] panamaphoenixnet> wrote in message
news:37f03117@news.povray.org...
> (1 - OriginalColor)    ?
>
>


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From: Nieminen Juha
Subject: Re: Media and Opposite Colors
Date: 28 Sep 1999 05:35:03
Message: <37f08bc7@news.povray.org>
Ken <tyl### [at] pacbellnet> wrote:

:> (1 - OriginalColor)    ?

: rgb<1,0,0> - rgb<1,0,0> = black.

  Since when 1 has been equal to <1,0,0>?

-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/


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From: Ken
Subject: Re: Media and Opposite Colors
Date: 28 Sep 1999 05:39:43
Message: <37F08C7B.38B811B@pacbell.net>
Nieminen Juha wrote:
> 
> Ken <tyl### [at] pacbellnet> wrote:
> 
> :> (1 - OriginalColor)    ?
> 
> : rgb<1,0,0> - rgb<1,0,0> = black.
> 
>   Since when 1 has been equal to <1,0,0>?

Read the rest of the thread and the answer shall be revealed to you...

-- 
Ken Tyler
1100+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html


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