POV-Ray : Newsgroups : povray.beta-test : less saturation with more cores? Server Time
17 May 2024 16:53:38 EDT (-0400)
  less saturation with more cores? (Message 1 to 3 of 3)  
From: Matthias
Subject: less saturation with more cores?
Date: 16 Sep 2011 19:50:01
Message: <web.4e73e005a1ac5613fed32f960@news.povray.org>
I observed an oddity I have no explanation for. I run RC3 unofficial on 3 Macs.
Two of them have two cores, and behave identical. The third has 8 cores, and
files with mesh objects result in clearly less saturated images. I have
double-checked that I am using the same files with the same settings, and I am
comparing the generated images, not just the gamma-adjusted previews. I'll be
happy to provide a scene file together with the images I get. The only not too
common feature I use is interior_texture. Please advise.

Matthias


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From: clipka
Subject: Re: less saturation with more cores?
Date: 16 Sep 2011 20:39:13
Message: <4e73ec31$1@news.povray.org>
Am 17.09.2011 01:47, schrieb Matthias:
> I observed an oddity I have no explanation for. I run RC3 unofficial on 3 Macs.
> Two of them have two cores, and behave identical. The third has 8 cores, and
> files with mesh objects result in clearly less saturated images. I have
> double-checked that I am using the same files with the same settings, and I am
> comparing the generated images, not just the gamma-adjusted previews. I'll be
> happy to provide a scene file together with the images I get. The only not too
> common feature I use is interior_texture. Please advise.

Some things you could try:

- On the 8-core machine, use option +WT2 in the INI file or on the 
command line; this will reduce the numer of render threads to 2. If this 
changes behaviour to match the 2-core machines, then there's something 
fishy indeed.

- On all machines, use an INI file with the following settings 
explicitly specified:

   File_Gamma=sRGB
   Display_Gamma=sRGB
   +fn

If this makes all machines behave identically, then there's probably 
something different with your povray.ini file on the 8-core machine.


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From: Matthias
Subject: Re: less saturation with more cores?
Date: 16 Sep 2011 21:50:01
Message: <web.4e73fbcc7d142462fed32f960@news.povray.org>
clipka <ano### [at] anonymousorg> wrote:
> Am 17.09.2011 01:47, schrieb Matthias:
> > I observed an oddity I have no explanation for. I run RC3 unofficial on 3 Macs.
> > Two of them have two cores, and behave identical. The third has 8 cores, and
> > files with mesh objects result in clearly less saturated images. I have
> > double-checked that I am using the same files with the same settings, and I am
> > comparing the generated images, not just the gamma-adjusted previews. I'll be
> > happy to provide a scene file together with the images I get. The only not too
> > common feature I use is interior_texture. Please advise.
>
> Some things you could try:
>
> - On the 8-core machine, use option +WT2 in the INI file or on the
> command line; this will reduce the numer of render threads to 2. If this
> changes behaviour to match the 2-core machines, then there's something
> fishy indeed.
>
> - On all machines, use an INI file with the following settings
> explicitly specified:
>
>    File_Gamma=sRGB
>    Display_Gamma=sRGB
>    +fn
>
> If this makes all machines behave identically, then there's probably
> something different with your povray.ini file on the 8-core machine.

Thanks for the quick response. This pointed me the right way.
It looks like as if on my more saturated
systems the display gamma defaults to 2.2, while on the less saturated one it
defaults to 0. I am not sure why that happened, but it's easy to fix for me now.
Thanks!

Matthias


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