I just spent two hours figuring out why I didn't get any photons when I
found that a looks_like{sphere .. statement in my light_source was to blame.
Adding pass_through for the sphere corrected this, but wouldn't it be a good
idea to have it set as default for looks_like objects?

sig

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In general photons act a bit ilogically with shadowless object. When you
make an object shadowless and the light passes through that object, it's
logical to expect photons to pass through as well. I don't know why the
shadowless-keyword is ignored by the photons calculations.

-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

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Warp <war### [at] tagpovrayorg> wrote...
>   In general photons act a bit ilogically with shadowless object. When you
> make an object shadowless and the light passes through that object, it's
> logical to expect photons to pass through as well. I don't know why the
> shadowless-keyword is ignored by the photons calculations.

Photon interaction with objects is a bit more complicated than shadow-ray
interaction.  However, it's not to difficutl to make no_shadow work like
pass_through.  This will decrease the amount of control you have over your
objects (currently, you can have an object that uses no_shadow but not
pass_through, but if I make this change then you will not be able to use the
no_shadow feature without the pass_through feature).  Comments?

-Nathan

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Warp wrote:
> 
>   In general photons act a bit ilogically with shadowless object. When you
> make an object shadowless and the light passes through that object, it's
> logical to expect photons to pass through as well. I don't know why the
> shadowless-keyword is ignored by the photons calculations.

Yes, well I don't know either why there's a seperate keyword for photons and
regular lights. More flexibility I guess. What I'm saying is that
pass_through could have been enabeled by default for looks_like objects,
just as shadowless is.

sig

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> (currently, you can have an object that uses no_shadow but not
> pass_through,

I think this is good because, even if this is perhaps not logical,
this allow more control and effect in a scene.

Fabian.

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Nathan Kopp <Nat### [at] koppcom> wrote:
: Photon interaction with objects is a bit more complicated than shadow-ray
: interaction.  However, it's not to difficutl to make no_shadow work like
: pass_through.  This will decrease the amount of control you have over your
: objects (currently, you can have an object that uses no_shadow but not
: pass_through, but if I make this change then you will not be able to use the
: no_shadow feature without the pass_through feature).  Comments?

  I think that a compromise could be the perfect solution:

  By default, applying no_shadow to an object also applies pass_through
to it.
  If you don't want photons passing through, you can specify it like this:

object
{ MyObject
  no_shadow
  photons { pass_through off }
}

-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

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Warp wrote:
>   By default, applying no_shadow to an object also applies pass_through

I agree.

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Sigmund Kyrre Aas wrote:
> 
> Yes, well I don't know either why there's a seperate keyword for photons and
> regular lights. More flexibility I guess. What I'm saying is that
> pass_through could have been enabeled by default for looks_like objects,
> just as shadowless is.
> 
> sig

Sorry, replace shadowless with no_shadow.

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