POV-Ray : Newsgroups : povray.binaries.images : interior fade_color and photons Server Time
18 Nov 2024 14:24:26 EST (-0500)
  interior fade_color and photons (Message 1 to 4 of 4)  
From: Ross
Subject: interior fade_color and photons
Date: 2 Aug 2005 19:32:28
Message: <42f0028c@news.povray.org>
It seems if i turn photons on, fade_color on the sphere part of the
exclamation mark disappears and is rendered simply as clear glass. with
photons off, the sphere is rendered colored. Scene file is in
povray.text.scene-files. Does anyone see an error in my pov script? Am I
missing a photons option? The same occurs, if i remember correctly, with
radiosity off.

thanks,
ross


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From: PM 2Ring
Subject: Re: interior fade_color and photons
Date: 5 Aug 2005 07:20:01
Message: <web.42f34b53d09e5752a196ebe30@news.povray.org>
"Ross" <rli### [at] everestkcnet> wrote:
> It seems if i turn photons on, fade_color on the sphere part of the
> exclamation mark disappears and is rendered simply as clear glass. with
> photons off, the sphere is rendered colored. Scene file is in
> povray.text.scene-files. Does anyone see an error in my pov script? Am I
> missing a photons option? The same occurs, if i remember correctly, with
> radiosity off.

Hi Ross,

I've had a quick look at your code, and I suggest that you use 'collect off'
in your photon block for the sphere - it's accumulating too many photons
and they are swamping the subtler effects.

See the 3.6 docs: 3.6.3.3  Photons FAQ and also look at the example scenes
in scenes/lights/ phot_met_glass.pov and glassthing.pov by Christoph
Hormann. There is a sign error in glassthing.pov, which causes the base of
the object to overlap with the floor, so you might want to fix that before
rendering.

Nice glass, BTW... I can't wait to see your final version.


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From: PM 2Ring
Subject: Re: interior fade_color and photons
Date: 5 Aug 2005 09:00:00
Message: <web.42f362a1d09e5752a196ebe30@news.povray.org>
"Ross" <rli### [at] everestkcnet> wrote:
> It seems if i turn photons on, fade_color on the sphere part of the
> exclamation mark disappears and is rendered simply as clear glass.

Ok, Ross, I've just done a few test renders, and my previous suggestion
about 'collect off' doesn't make a difference. Sorry about that. :(

However, I have solved your problem: it's just a matter of coincident
surfaces: move your plane back 0.2 units and all will be fine.

You might like to experiment with 'conserve_energy', although it will make
your glass darker & the colour a bit washed out, so they will need
adjusting.

How come there is a #version 3.5 directive in this scene? Are you actually
using POV 3.5? If so, you really should use 3.6, version 3.5 has a bug that
causes green spots on glass that uses both 'fresnel' reflection &
'conserve_energy'.

Also, is there a reason why all your glass objects are hollow?

Here's a quick render I've just done, using conserve_energy, radiosity and
photons, but with a count of 300000, and antialias settings of +A0.5 +AM2
+R2


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From: Ross
Subject: Re: interior fade_color and photons
Date: 5 Aug 2005 10:26:48
Message: <42f37728$1@news.povray.org>
"PM 2Ring" <nomail@nomail> wrote in message
news:web.42f362a1d09e5752a196ebe30@news.povray.org...
> "Ross" <rli### [at] everestkcnet> wrote:
> > It seems if i turn photons on, fade_color on the sphere part of the
> > exclamation mark disappears and is rendered simply as clear glass.
>
> Ok, Ross, I've just done a few test renders, and my previous suggestion
> about 'collect off' doesn't make a difference. Sorry about that. :(

thanks for trying :)

>
> However, I have solved your problem: it's just a matter of coincident
> surfaces: move your plane back 0.2 units and all will be fine.

really? hmm. interesting. ok, thanks i'll give it a go. I never even
considered coincident surfaces in this case. I didn't see the usual tell
tale signs.

>
> You might like to experiment with 'conserve_energy', although it will make
> your glass darker & the colour a bit washed out, so they will need
> adjusting.
>
> How come there is a #version 3.5 directive in this scene? Are you actually
> using POV 3.5? If so, you really should use 3.6, version 3.5 has a bug
that
> causes green spots on glass that uses both 'fresnel' reflection &
> 'conserve_energy'.

simply because the "Insert" menus of POV-mode for emacs insert it if i do
something like Insert->Basic Scene and I never think of changing it. I'm
actually using 3.6.

>
> Also, is there a reason why all your glass objects are hollow?

not yet!

Thanks for finding the problem. Of to render it with Way Too Many photons ;)


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