Burki nous apporta ses lumieres en ce 22-03-2007 11:36:
> "Kevin" <Kev### [at] Karneycom> wrote:
>> I need a transparent translucent ghostly sphere - just visible - with no
>> reflections, no refraction and no specular high-lights.


> Hi Kevin,

> if you want to be sure to have no specular high-lights, set specular to zero
> in the finish block.

> You have to decide if you want the sphere transparent or translucent,
> example:

> // put this in the insert scene template "Checkered floor"
> //instead of the reflective sphere.

> sphere {
>   0.0, 1
>     pigment {
>       color rgb <1,0,0>
>       filter 0.85
>     }
>     finish{
>       diffuse 0.6
>       ambient 0.1
>       specular 0.0
If you don't specify any specular, it default to disabled, or no specular 
highlighting. Same thing with phong.
>     }
>     no_shadow
>     #declare milky = true;
>     // true -> translucent, false -> transparent
>     #if (milky)
>      hollow // turns media on
>     #end
>     interior {
>           ior 1.000
>           media {
>                scattering {
>                     4,   // scattering type 1=isotropic; 2=Mie haze; 3=Mie
> murky
>                          // 4=Rayleigh; 5=Henyey-Greenstein
>                     0.8  // color and/or media density
>                }
>           }
>      }
> }
> // ---------------

> With milky=true it is translucent (with scattering medium), with milky=false
> it is transparent (without medium).

> Also check which one is better for you:
> filter (0-100%, 85% here) or transmit.
> "transmit" fades out the color, "filter" just makes the objects transparent
> without loosing the color.

> ior is set to 1, so no refraction.
If you don't set any ior value, it default to 1 or NO refraction.



> Yours,
> Bu.


Another way, faster than using a media, is to use fading. Here's how it's done:

interior{fade_color Your_Color fade_distance Some_distance fade_power 1}

You need to adjust fade_distance to suit your situation. A large object, or one 
you want only lightly coloured, needs a larger value, while small ones, or 
strongly coloured, need small value.
This give "substance" to the interior of your sphere. The longer you travel 
inside it, the more the fade colour will apears. It's a LOT faster than 
scattering media.

A key difference: if a beam of light goes trough your object, the one filled 
with media will make the beam visible, while the fading one won't.
Depending on your need, you chose one, the other, or both as they are compatible.

-- 
Alain
-------------------------------------------------
Wouldn't it be nice if whenever we messed up our life we could simply press 
'Ctrl Alt Delete' and start all over?

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