POV-Ray : Newsgroups : povray.advanced-users : Intense Light and semi-transparent paper Server Time
29 Jul 2024 06:15:22 EDT (-0400)
  Intense Light and semi-transparent paper (Message 1 to 3 of 3)  
From: George
Subject: Intense Light and semi-transparent paper
Date: 20 Dec 2002 20:25:03
Message: <web.3e03c27775f9e51c514daf780@news.povray.org>
Hello

I am Trying to get the same effect one has when holding a
semi-transparent piece of paper (rice paper for example)
into a laser. The Laser passes through but a lot of light
is scattered and an bright Spot apears on the paper.
Right now I am using the following to create the paper:

box{<-2.5e-02,-2.5e+01,-2.5e+01>,<2.5e-02,2.5e+01,2.5e+01>
  interior{fade_power 2 fade_distance 3000}
  texture{pigment{color 1.0*White transmit 0.75}}
  translate <1.6e+02,0,0> }

However I do not get the bright spot due to scattering.
What am I missing?

Regards,

George


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From: Tek
Subject: Re: Intense Light and semi-transparent paper
Date: 20 Dec 2002 21:16:21
Message: <3e03cef5@news.povray.org>
fade power and fade distance don't simulate scattering. To get a fairly accurate
model you should use scattering media.

Though you can probably fake the effect quite cheaply using a completely thin
object (e.g. a triangle) and pov's double_illuminate flag.

--
Tek
http://www.evilsuperbrain.com


George <nomail@nomail> wrote in message
news:web.3e03c27775f9e51c514daf780@news.povray.org...
> Hello
>
> I am Trying to get the same effect one has when holding a
> semi-transparent piece of paper (rice paper for example)
> into a laser. The Laser passes through but a lot of light
> is scattered and an bright Spot apears on the paper.
> Right now I am using the following to create the paper:
>
> box{<-2.5e-02,-2.5e+01,-2.5e+01>,<2.5e-02,2.5e+01,2.5e+01>
>   interior{fade_power 2 fade_distance 3000}
>   texture{pigment{color 1.0*White transmit 0.75}}
>   translate <1.6e+02,0,0> }
>
> However I do not get the bright spot due to scattering.
> What am I missing?
>
> Regards,
>
> George
>
>


Post a reply to this message

From: George
Subject: Re: Intense Light and semi-transparent paper
Date: 21 Dec 2002 08:50:03
Message: <web.3e0470d1b305e87cca5b3bef0@news.povray.org>
Tek wrote:
>fade power and fade distance don't simulate scattering. To get a fairly accurate

I did not use them with that intention anyway.

>model you should use scattering media.

Ok. I will give it a shot :-)

>
>Though you can probably fake the effect quite cheaply using a completely thin
>object (e.g. a triangle) and pov's double_illuminate flag.
>

Faking is not an option, in the context I am using povray.

Regards,

George

>--
>Tek
>http://www.evilsuperbrain.com
>
>
>George <nomail[at]nomail> wrote in message
>news:web.3e03c27775f9e51c514daf780[at]news.povray.org...
>> Hello
>>
>> I am Trying to get the same effect one has when holding a
>> semi-transparent piece of paper (rice paper for example)
>> into a laser. The Laser passes through but a lot of light
>> is scattered and an bright Spot apears on the paper.
>> Right now I am using the following to create the paper:
>>
>> box{<-2.5e-02,-2.5e+01,-2.5e+01>,<2.5e-02,2.5e+01,2.5e+01>
>>   interior{fade_power 2 fade_distance 3000}
>>   texture{pigment{color 1.0*White transmit 0.75}}
>>   translate <1.6e+02,0,0> }
>>
>> However I do not get the bright spot due to scattering.
>> What am I missing?
>>
>> Regards,
>>
>> George
>>
>>
>


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