> "sbakke" <nomail@nomail> wrote:
>>> Thank-you!
>>>
>>> Just an image map - the only trick is to make it high rez. The floor is a
>>> repeating 1024x1024 PNG.
>>>
>>> I'll try to post the POV file once I get it al cleaned up.
>>>
>>> Cheers,
>>> Edouard.
>>
>> Thanks!
>>
>> Steve
>
>
>
> I am working on rendering a glass box and have met some problems. Would you mind
> sharing your code with me? Thanks.
>

For the texture, it's normaly beter to start with a fully transparent 
pigment like rgbt 1.

You absolutely need an interior statement. It have to set the ior for 
your glass. Common glass have an ior around 1.5, but it can range from 

presence of disolved materials will change it. Most gemms have ior in 
the 1.7 to 2.5 range.
Adding some dispersion also help, but will increase the rendering time.
Use fade_color, fade_distance and fade_power 1 to provide any 
colouration needed.
An interior block for a glass object can look like this:

interior{
ior 1.5  // Typical or default glass ior
dispersion 1.01 // Keep larger than but close to 1.
fade_color<0.7, 0.98, 0.8> // slightly greenish glass
fade_distance 1
// adjust as needed. Small increase the colour intensity.
fade_power 1 // The only realy realistic value in this case
}

A very important aspect is the reflectiveness of the glass. Your finish 
should have:
finish{reflection{1 fresnel} conserve_energy}
This turn on the fresnel reflection going from almost zero to total 
reflectiveness.
Also adding some relatively tight specular of phong highlight can 
improve the aspect. It's often beter to use a specular or phong value in 
the 0.5 to 0.7 range, but you are not limited to that range.
You can use both specular and phong.

If your box is made of several parts, you should use merge instead of 
union to remove the internal surfaces.
You need to be carefull about coincident surfaces everywhere. They WILL 
cause problem if you are not carefull.

In the global_settings{...} section, you need to increase 
max_trace_level as the default of 5 is normaly conciderably to low.



Alain

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