POV-Ray : Newsgroups : povray.general : glass panes Server Time
2 Aug 2024 06:15:03 EDT (-0400)
  glass panes (Message 1 to 6 of 6)  
From: Maurice
Subject: glass panes
Date: 21 Jan 2005 17:13:05
Message: <41f17e71$1@news.povray.org>
Hi,

I'm wondering what would be a good texture,finish and interior for you 
average windowpane glass?

I'm currently using the settings below, but I woner if it could be 
optimised:

// Glass of window panes
#declare T_Glass=texture{
   pigment{
     color rgbt 1
   }
   finish{
     ambient 0.1
     diffuse 0.04
     reflection{ 0.5 fresnel on }
     conserve_energy
   }
}
#declare I_Glass=interior{
   ior 1.5
   fade_power 2 //1.5
   fade_distance 1
   fade_color <0.70, 0.7, 0.9>
   //dispersion 1.01
   //dispersion_samples 100
}

-- 
Maurice


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From: Maurice
Subject: Re: glass panes
Date: 21 Jan 2005 17:16:06
Message: <41f17f26$1@news.povray.org>
Maurice wrote:
> Hi,
> 
> I'm wondering what would be a good texture,finish and interior for you 
> average windowpane glass?

I forgot to mention that I'm particularly struggeling with the 
fade_power, fade_distance and fade_color values. The manual is rather 
cryptic about those. I guess fade_power would have to be 2 in order to 
be physically correct, but the fade distance of window pane glass I have 
no idea what it should be. Also the fade_color.


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From: Ross
Subject: Re: glass panes
Date: 21 Jan 2005 18:04:36
Message: <41f18a84$1@news.povray.org>
"Maurice" <cel### [at] nospamhotmailcom> wrote in message
news:41f17e71$1@news.povray.org...
> Hi,
>
> I'm wondering what would be a good texture,finish and interior for you
> average windowpane glass?
>
> I'm currently using the settings below, but I woner if it could be
> optimised:
>
> // Glass of window panes
> #declare T_Glass=texture{
>    pigment{
>      color rgbt 1
>    }
>    finish{
>      ambient 0.1
>      diffuse 0.04
>      reflection{ 0.5 fresnel on }
>      conserve_energy
>    }
> }

i think glass would have "ambient 0"

for reflection, i think it would be a variable reflection. My reason is that
if you look straight at the glass, you can see pretty much straight through
it (depending on the type of glass i guess) and if you look at it at a
shallow angle it is more reflective. This effect is very pronounces with
water anyway. glass too i think. i'm not sure of the physical values, but
something like "reflection {0.1, 0.5 fresnel on}"

> #declare I_Glass=interior{
>    ior 1.5
>    fade_power 2 //1.5
>    fade_distance 1
>    fade_color <0.70, 0.7, 0.9>
>    //dispersion 1.01
>    //dispersion_samples 100
> }
>

fade stuff... hopefully someone else can help you on that :) I would have
left it at defaults. I've only ever really used them for lights. i've used
fade_color for murky water once...

good luck!


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From: Alain
Subject: Re: glass panes
Date: 21 Jan 2005 21:44:57
Message: <41f1be29$1@news.povray.org>
Maurice nous apporta ses lumieres en ce 2005-01-21 17:13:
> Hi,
> 
> I'm wondering what would be a good texture,finish and interior for you 
> average windowpane glass?
> 
> I'm currently using the settings below, but I woner if it could be 
> optimised:
> 
> // Glass of window panes
> #declare T_Glass=texture{
>   pigment{
>     color rgbt 1
>   }
>   finish{
>     ambient 0.1
>     diffuse 0.04
>     reflection{ 0.5 fresnel on }
>     conserve_energy
>   }
> }
> #declare I_Glass=interior{
>   ior 1.5
>   fade_power 2 //1.5
>   fade_distance 1
>   fade_color <0.70, 0.7, 0.9>
>   //dispersion 1.01
>   //dispersion_samples 100
> }
> 
You can probably get by without any fade, unless your glass is very thick. Plate glass
is slightly 
greenish, not pure white. Normal glass is not perfectly transparent:
  color rgbft<0.95, 0.99, 0.94, 0.7, 0.23> can give you a good glass pane.

Alain


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From: Christopher James Huff
Subject: Re: glass panes
Date: 25 Jan 2005 15:16:06
Message: <cjameshuff-7D6F49.15160925012005@news.povray.org>
In article <41f1be29$1@news.povray.org>,
 Alain <ele### [at] netscapenet> wrote:

> You can probably get by without any fade, unless your glass is very thick. 
> Plate glass is slightly 
> greenish, not pure white. Normal glass is not perfectly transparent:
>   color rgbft<0.95, 0.99, 0.94, 0.7, 0.23> can give you a good glass pane.

If you see the glass at a shallow angle or see a thin edge of it, the 
fading will be important because of the contribution of "trapped" rays. 
It is not very computationally expensive, so I usually use fading with a 
perfectly transparent surface pigment. (Unless the surface is dirty, 
that is.)

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: <chr### [at] tagpovrayorg>
http://tag.povray.org/


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From: Christopher James Huff
Subject: Re: glass panes
Date: 25 Jan 2005 18:07:47
Message: <cjameshuff-828B7D.18075025012005@news.povray.org>
In article <41f17f26$1@news.povray.org>,
 Maurice <cel### [at] nospamhotmailcom> wrote:

> I forgot to mention that I'm particularly struggeling with the 
> fade_power, fade_distance and fade_color values. The manual is rather 
> cryptic about those. I guess fade_power would have to be 2 in order to 
> be physically correct, but the fade distance of window pane glass I have 
> no idea what it should be. Also the fade_color.

fade_color is the apparent color of the material. For red glass, it 
should be red. A side note: I rarely use pure colors, I'd use tiny 
values of green and blue as well, for more realistic response to very 
bright light.

fade_power controls the function of distance used. Most realistic is a 
fade_power of 1000, which tells POV to use exponential attenuation. 
(Yeah, that's a terrible syntax for this...)

fade_distance controls the density...doubling it will make it reach a 
given proportion of the fade_color color in half the distance.

What I usually do is set fade_power to 1000, pin down the approximate 
color I want, then tweak fade_distance until it's the right density.

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: <chr### [at] tagpovrayorg>
http://tag.povray.org/


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