I don't seem to be able to render photon caustics in a media container at
all.  With both turned on the caustics diappear, the media disappears in
the shadow of my transparent object, and shadows go completely black.  With
only media turned on media works just fine with proper shading in the
shadows.  With only photons turned on the caustics work fine.  I all cases
in internal diffusion works.  I have spent hours with the documentation to
no avail.  What am I missing? Here are the settings I last tried:

global_settings {
  assumed_gamma 1.0
  max_trace_level 15
   photons {
     count 20000
     jitter .4
     media 300
     max_trace_level 35
   }
}

In my object's interior:

  interior{
    ior 2.2
    dispersion 1.9
    dispersion_samples 120
  }

My objects' photon block:

  photons{
    target
    reflection on
    refraction on
  }

My media container:

cylinder{
  <0,-.01,0>,<0,14,0>,8
  texture{
    pigment{ color rgbt <1,1,1,1>}
  }
  interior{
    media{
      scattering { 1, rgb 0.03}
      intervals 1
      samples 30,100
      method 3
    }
  }
  hollow
}

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"Lonnie" <lon### [at] yahoocom> wrote:
> I don't seem to be able to render photon caustics in a media container at
> all.  With both turned on the caustics diappear, the media disappears in
> the shadow of my transparent object, and shadows go completely black.  With
> only media turned on media works just fine with proper shading in the
> shadows.  With only photons turned on the caustics work fine.  I all cases
> in internal diffusion works.  I have spent hours with the documentation to
> no avail.  What am I missing? Here are the settings I last tried:
>
> global_settings {
>   assumed_gamma 1.0
>   max_trace_level 15
>    photons {
>      count 20000
>      jitter .4
>      media 300
>      max_trace_level 35
>    }
> }
>
> In my object's interior:
>
>   interior{
>     ior 2.2
>     dispersion 1.9
>     dispersion_samples 120
>   }
>
> My objects' photon block:
>
>   photons{
>     target
>     reflection on
>     refraction on
>   }
>
> My media container:
>
> cylinder{
>   <0,-.01,0>,<0,14,0>,8
>   texture{
>     pigment{ color rgbt <1,1,1,1>}
>   }
>   interior{
>     media{
>       scattering { 1, rgb 0.03}
>       intervals 1
>       samples 30,100
>       method 3
>     }
>   }
>   hollow
> }

I think you need a photons {pass_through} on your media container.

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"Mienai" <Mienai> wrote:
> "Lonnie" <lon### [at] yahoocom> wrote:
> > I don't seem to be able to render photon caustics in a media container at
> > all.  With both turned on the caustics diappear, the media disappears in
> > the shadow of my transparent object, and shadows go completely black.  With
> > only media turned on media works just fine with proper shading in the
> > shadows.  With only photons turned on the caustics work fine.  I all cases
> > in internal diffusion works.  I have spent hours with the documentation to
> > no avail.  What am I missing? Here are the settings I last tried:
> >
> > global_settings {
> >   assumed_gamma 1.0
> >   max_trace_level 15
> >    photons {
> >      count 20000
> >      jitter .4
> >      media 300
> >      max_trace_level 35
> >    }
> > }
> >
> > In my object's interior:
> >
> >   interior{
> >     ior 2.2
> >     dispersion 1.9
> >     dispersion_samples 120
> >   }
> >
> > My objects' photon block:
> >
> >   photons{
> >     target
> >     reflection on
> >     refraction on
> >   }
> >
> > My media container:
> >
> > cylinder{
> >   <0,-.01,0>,<0,14,0>,8
> >   texture{
> >     pigment{ color rgbt <1,1,1,1>}
> >   }
> >   interior{
> >     media{
> >       scattering { 1, rgb 0.03}
> >       intervals 1
> >       samples 30,100
> >       method 3
> >     }
> >   }
> >   hollow
> > }
>
> I think you need a photons {pass_through} on your media container.

Thanks Mienai, that fixed everything.

Post a reply to this message

> > I think you need a photons {pass_through} on your media container.
>
> Thanks Mienai, that fixed everything.

Hmm, why was that necessary? Shouldn't photons pass through the transparent
surface anyway?

 - Slime
 [ http://www.slimeland.com/ ]

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"Slime" <fak### [at] emailaddress> wrote:
> > > I think you need a photons {pass_through} on your media container.
> >
> > Thanks Mienai, that fixed everything.
>
> Hmm, why was that necessary? Shouldn't photons pass through the transparent
> surface anyway?
>
>  - Slime
>  [ http://www.slimeland.com/ ]

Apparently they will not, but I need to run a LOT more tests using photons,
media, and radiosity together.  All I am sure of is that once I made the
media container a target I got explosive chroma dispersion, both on solid
surfaces and in the media - which is what I was after.  I still find no
mention of this in the documentation.  It is posted in binaries/images.
"Torture...  Temple of Alden"

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