Am 13.07.2012 18:24, schrieb Crippso:
>
> I tried to use media but cant get it to work properly. Still when my xscan
> paramter = 4 the reflection is too bright, it should be much weaker than when
> xscan = 3. Here is how i modified the absorber object. The only other change I
> made was to the photons global setting where i added "media 100". Am i doing
> something wrong?

The "media" keyword in the global photons block is irrelevant for your 
case; it is intended for scattering media.


> object{

(BTW, while wrapping your "box" in an "object" statement doesn't hurt, 
it's totally unnecessary; you need "object" only when you have 
#declare'd an object and want to add it to the scene.)

> box
> {
>     <-extent,-extent,t_st> <extent,extent,t_st+t_abs>
>     hollow
>     pigment{rgbt 1}
>     finish
>     {
>       reflection{0,1 fresnel}
>       conserve_energy
>     }
>
>     interior{ior cmt_ior fade_distance cmt_abs fade_power 1000

Remove the "fade_distance" and "fade_power" statements; after all, 
you're trying to replace them with media.

>         media{
>          absorption <1,1,1>

You may need to increase absorption; note that its parameter is not 
limited to the range [0..1].

Theoretically, you should set:

     absorption = <1,1,1> / cmt_abs

to get the same results as you'd get with properly computed fade.

>          intervals 3
>          samples 1,1         }

Remove the "intervals" and "samples" statements; the default values 
should be perfectly fine for uniform media as in your case.

>
>     }
>
>     PhotonTarget(no, yes, yes, yes)
> }
> }

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