POV-Ray : Newsgroups : povray.binaries.images : Doubts about photons : Re: Doubts about photons Server Time
31 Jul 2024 00:30:11 EDT (-0400)
  Re: Doubts about photons  
From: Alain
Date: 22 Sep 2010 15:05:22
Message: <4c9a5372$1@news.povray.org>

> "Alain"<aze### [at] qwertyorg>  schreef in bericht
> news:4c98f8af$1@news.povray.org...
>> When light goes through a glass, it get spread out exept for the light
>> that goes through the thick base. And even then, given the shape of the
>> inside of your glasses, it get's a fair amount of spreading.
>>
>> In the non-photons version, light goes straight through the glass without
>> any deviation.
>>
>> Do you also use radiosity for that scene?
>
> Yes, I use also radiosity.
>
> This is possibly a difficult glass object to use photons with (from Ingo
> Jansen's grenadine.pov). One thing I noticed when I decreased the spacing
> parameter beyond a rather low value, was that the entire image became black.
>
> Is there a way to get *better* results? For the glasses I used collect on,
> with same results as with collect off for instance, and I switched
> reflection off keeping only refraction on (also in the light block).
>
> Thomas
>
>

collect on enable photons to show on the object's surface. On a glass 
object, most of the time, it's a waste.

You have a glass window pane. Is it set to passthrough? You may have to 
many photons if the window is set as a target. It may also prevent 
photons from reatching the glass if not set as a target.
Also, set the curtains as passthrough.

The photons block for the light_source is optional defaulting to 
photons{refection on refraction on area_light off}
You usualy don't need to change it.


Alain


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