POV-Ray : Newsgroups : povray.general : making perfectly transparent object with color Server Time
25 Dec 2024 01:27:42 EST (-0500)
  making perfectly transparent object with color (Message 1 to 3 of 3)  
From: yoon
Subject: making perfectly transparent object with color
Date: 17 Jul 2006 12:04:07
Message: <44bbb4f7@news.povray.org>
At first, make a white ball and then make a red box, which is bigger than
the ball, in front of the ball.

If I use the command "filter" or "transmit", I could see the ball through
the box.

But the color of ball(white) seem to be redder and dimmer than its original
because the light traverse through the red box.

If I put more red boxes in front of the ball, I will not be able to see the
ball because many boxes screen the light emitted from the white ball.

How can I see the white ball even if there are many boxes between the ball
and the camera?

Thank you.

JH



-- 
==========================================
 Yonsei University, Department of Astronomy
 Seoul, South Korea
 Graduate Student, Room #703
 Joo Heon Yoon in GEM
 jhy### [at] galaxyyonseiackr
==========================================


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From: Trevor G Quayle
Subject: Re: making perfectly transparent object with color
Date: 17 Jul 2006 13:45:00
Message: <web.44bbcbfa8936040dc150d4c10@news.povray.org>
"yoon" <jhy### [at] galaxyyonseiackr> wrote:
> At first, make a white ball and then make a red box, which is bigger than
> the ball, in front of the ball.
>
> If I use the command "filter" or "transmit", I could see the ball through
> the box.
>
> But the color of ball(white) seem to be redder and dimmer than its original
> because the light traverse through the red box.
>
> If I put more red boxes in front of the ball, I will not be able to see the
> ball because many boxes screen the light emitted from the white ball.
>
> How can I see the white ball even if there are many boxes between the ball
> and the camera?
>
> Thank you.
>
> JH
>

Try not to multipost in different groups, if someone has an answer, they'll
eventually respond.

For your problem, use filter as 1  (i.e., rgbf <1,0,0,1>) and everything
will be filtered red.  Using transmit with a value of 1 will not alter any
colours.  Using values less than 1 will fade light passing through by the
f/t component.
You should be able to put as many boxes as you want wnd still see the sphere
behind just as bright, but filtered aslong as you have max_trace_level high
enough, filter set to 1 and no fading added to the box interior.

Example:
//start

global_settings {max_trace_level 15}

camera {
  location  -10*z
  look_at   0
}


light_source{<0,100,-100>  rgb 1}

sphere{0 1
  texture{
    pigment{rgb 1}
    finish{ambient 0 diffuse 0.6}
  }
}


box{<-1.2,-1.2,-1.2><1.2,1.2,-1.3>
  texture{
    pigment{rgbf <1,0,0,1>}
    finish{ambient 0 diffuse 0.6}
  }

}

box{<-1.2,-1.2,-1.4><1.2,1.2,-1.5>
  texture{
    pigment{rgbf <1,0,0,1>}
    finish{ambient 0 diffuse 0.6}
  }

}

box{<-1.2,-1.2,-1.6><1.2,1.2,-1.8>
  texture{
    pigment{rgbf <1,0,0,1>}
    finish{ambient 0 diffuse 0.6}
  }

}


//end


-tgq


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From: yoon
Subject: Re: making perfectly transparent object with color
Date: 20 Jul 2006 11:23:16
Message: <44bf9fe4$1@news.povray.org>
Thank you.

However, it doesn't work.

I can't see any red boxes if I follow your comment.

"Trevor G Quayle" <Tin### [at] hotmailcom> wrote in message 
news:web.44bbcbfa8936040dc150d4c10@news.povray.org...
> "yoon" <jhy### [at] galaxyyonseiackr> wrote:
>> At first, make a white ball and then make a red box, which is bigger than
>> the ball, in front of the ball.
>>
>> If I use the command "filter" or "transmit", I could see the ball through
>> the box.
>>
>> But the color of ball(white) seem to be redder and dimmer than its 
>> original
>> because the light traverse through the red box.
>>
>> If I put more red boxes in front of the ball, I will not be able to see 
>> the
>> ball because many boxes screen the light emitted from the white ball.
>>
>> How can I see the white ball even if there are many boxes between the 
>> ball
>> and the camera?
>>
>> Thank you.
>>
>> JH
>>
>
> Try not to multipost in different groups, if someone has an answer, 
> they'll
> eventually respond.
>
> For your problem, use filter as 1  (i.e., rgbf <1,0,0,1>) and everything
> will be filtered red.  Using transmit with a value of 1 will not alter any
> colours.  Using values less than 1 will fade light passing through by the
> f/t component.
> You should be able to put as many boxes as you want wnd still see the 
> sphere
> behind just as bright, but filtered aslong as you have max_trace_level 
> high
> enough, filter set to 1 and no fading added to the box interior.
>
> Example:
> //start
>
> global_settings {max_trace_level 15}
>
> camera {
>  location  -10*z
>  look_at   0
> }
>
>
> light_source{<0,100,-100>  rgb 1}
>
> sphere{0 1
>  texture{
>    pigment{rgb 1}
>    finish{ambient 0 diffuse 0.6}
>  }
> }
>
>
> box{<-1.2,-1.2,-1.2><1.2,1.2,-1.3>
>  texture{
>    pigment{rgbf <1,0,0,1>}
>    finish{ambient 0 diffuse 0.6}
>  }
>
> }
>
> box{<-1.2,-1.2,-1.4><1.2,1.2,-1.5>
>  texture{
>    pigment{rgbf <1,0,0,1>}
>    finish{ambient 0 diffuse 0.6}
>  }
>
> }
>
> box{<-1.2,-1.2,-1.6><1.2,1.2,-1.8>
>  texture{
>    pigment{rgbf <1,0,0,1>}
>    finish{ambient 0 diffuse 0.6}
>  }
>
> }
>
>
> //end
>
>
> -tgq
>
>
>


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