POV-Ray : Newsgroups : povray.general : Photon Brightness Server Time
25 Dec 2024 20:19:54 EST (-0500)
  Photon Brightness (Message 1 to 3 of 3)  
From: Sereib
Subject: Photon Brightness
Date: 23 Sep 2013 06:25:00
Message: <web.5240160e37022733dc614e470@news.povray.org>
Hello,

when using the "photons" feature in a scene, is there any option to adjust the
brightness of the effect "photons" causes, as it is possible for the "radiosity"
feature with the brightness statement in the global radiosity block?

I know, POV-Ray just wants to create realistic images, but sometimes it can be
reasonable to "improve" realism to get the look desired.

In this special case, I have some quartz objects on a dark surface, and I would
like to make the diffraction pattern  more bright without increasing the
brightness of the surface.

Thank you!


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From: Alain
Subject: Re: Photon Brightness
Date: 23 Sep 2013 16:02:05
Message: <52409e3d$1@news.povray.org>

> Hello,
>
> when using the "photons" feature in a scene, is there any option to adjust the
> brightness of the effect "photons" causes, as it is possible for the "radiosity"
> feature with the brightness statement in the global radiosity block?
>
> I know, POV-Ray just wants to create realistic images, but sometimes it can be
> reasonable to "improve" realism to get the look desired.
>
> In this special case, I have some quartz objects on a dark surface, and I would
> like to make the diffraction pattern  more bright without increasing the
> brightness of the surface.
>
> Thank you!
>
>

You can try a 2 pass process.
In the first pass, use a brighter light and save the photons to a file.
In the second pass, bring the light to it's intended value and load the 
photons file.

When you load the photons, no new photons are shot. If the light used to 
create the saved photons is much brighter, then the saved, and reused, 
photons will be that much brighter.

You may want to increase the dispersion_samples value to get smoother 
redults.

Alain


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From: Sereib
Subject: Re: Photon Brightness
Date: 24 Sep 2013 07:25:00
Message: <web.52417688f533833dc24107590@news.povray.org>
.... good idea, thank you very much!!


Alain <kua### [at] videotronca> wrote:

> > Hello,
> >
> > when using the "photons" feature in a scene, is there any option to adjust the
> > brightness of the effect "photons" causes, as it is possible for the "radiosity"
> > feature with the brightness statement in the global radiosity block?
> >
> > I know, POV-Ray just wants to create realistic images, but sometimes it can be
> > reasonable to "improve" realism to get the look desired.
> >
> > In this special case, I have some quartz objects on a dark surface, and I would
> > like to make the diffraction pattern  more bright without increasing the
> > brightness of the surface.
> >
> > Thank you!
> >
> >
>
> You can try a 2 pass process.
> In the first pass, use a brighter light and save the photons to a file.
> In the second pass, bring the light to it's intended value and load the
> photons file.
>
> When you load the photons, no new photons are shot. If the light used to
> create the saved photons is much brighter, then the saved, and reused,
> photons will be that much brighter.
>
> You may want to increase the dispersion_samples value to get smoother
> redults.
>
> Alain


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