I have been trying to model a hollow glass sphere (cut in half via a clipped
plane)  Whenever I place the glass object over some steel stuff
(polished_chrome) the part under the glass becomes pretty dark compared to
the same stuff outside the glass.  I know that some light will be reduced
but is there any way to let the light come through 99% or so?  I can
increase the ambient level of the steel under the glass but then it starts
to look "plasticky."  I would like to retain the "reflectivity" of the glass
just allow enough light back through so I don't have to mess with the steel
ambient level.

Here is the object code:

#declare Dome =
difference {
   sphere { <0,0,0> 2.35}
   sphere { <0,0,0> 2.25}
   texture {pigment { rgbf <1,1,1,1>}}
   interior {ior 1.0 }
   finish{
      reflection 0.1
      diffuse 0.1
      specular 0.1
      phong 0.15
   }
   scale <1,1,0.25>
   clipped_by{plane{z,0}}
}

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Try increasing the max_trace_level in your global setting statement.

See also -
http://www.students.tut.fi/~warp/povVFAQ/languageVFAQ.html#maxtracelevel

-- 
Ken Tyler - 1400+ POV-Ray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

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In article <39595aa0@news.povray.org>, "Patrick Dugan" 
<pat### [at] netinsnet> wrote:

> I have been trying to model a hollow glass sphere (cut in half via a 
> clipped plane)  Whenever I place the glass object over some steel 
> stuff (polished_chrome) the part under the glass becomes pretty dark 
> compared to the same stuff outside the glass.  I know that some light 
> will be reduced but is there any way to let the light come through 
> 99% or so?  I can increase the ambient level of the steel under the 
> glass but then it starts to look "plasticky."  I would like to retain 
> the "reflectivity" of the glass just allow enough light back through 
> so I don't have to mess with the steel ambient level.

Having a filter or transmit of 1 *is* 100% transparent, though things 
like reflections may obscure this.
You might be running into max_trace_level in global_settings if you 
haven't raised it from the default. It controls the number of surfaces 
POV will refract, transmit, or reflect rays through. Beyond this limit, 
the background color is used. Since the default background is black, 
this usually produces black streaks, specks, darkened areas, or other 
artifacts.

-- 
Christopher James Huff - Personal e-mail: chr### [at] maccom
TAG(Technical Assistance Group) e-mail: chr### [at] tagpovrayorg
Personal Web page: http://homepage.mac.com/chrishuff/
TAG Web page: http://tag.povray.org/

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