This image was made for the TC-RTC competition. It uses photons. However, 
for esthetic reasons,  I much prefer the version without photons I uploaded 
to the site: http://www.tc-rtc.co.uk/imagenewdisplay/stills/301/Glass.html

It is probably me, but photons made the glass, its shadow, and its content 
darker.

Thomas

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> This image was made for the TC-RTC competition. It uses photons. However,
> for esthetic reasons,  I much prefer the version without photons I uploaded
> to the site: http://www.tc-rtc.co.uk/imagenewdisplay/stills/301/Glass.html
>
> It is probably me, but photons made the glass, its shadow, and its content
> darker.
>
> Thomas
>
>
>

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?


Alain

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"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

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> "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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"Alain" <aze### [at] qwertyorg> schreef in bericht 
news:4c9a5372$1@news.povray.org...
> 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.
>

I did a number of corrections and changes to my settings. The result of 
photon mapping seems good to me (note: no aa here).

Thomas

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