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25 Dec 2024 23:09:03 EST (-0500)
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From: Stephen
Subject: Re: Physically based rendering
Date: 26 Jun 2015 02:58:13
Message: <558cf805$1@news.povray.org>
On 26/06/2015 07:34, And wrote:
> "And" <49341109@ntnu.edu.tw> wrote:
>> Thank you. I knew this. It must do. This is due to POV-Ray's light source
>> defines the color of a diffuse surface which is illuminate by the light source
>> at a distance of fade_distance.
>
> I'm very smart.!!
>

LOL
You are too. :-)

-- 

Regards
     Stephen


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From: Thomas de Groot
Subject: Re: Physically based rendering
Date: 26 Jun 2015 03:47:23
Message: <558d038b$1@news.povray.org>
On 26-6-2015 8:58, Stephen wrote:
> On 26/06/2015 07:34, And wrote:
>> "And" <49341109@ntnu.edu.tw> wrote:
>>> Thank you. I knew this. It must do. This is due to POV-Ray's light
>>> source
>>> defines the color of a diffuse surface which is illuminate by the
>>> light source
>>> at a distance of fade_distance.
>>
>> I'm very smart.!!
>>
>
> LOL
> You are too. :-)
>

Why do I feel depressed now? :-)

-- 
Thomas


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From: Thomas de Groot
Subject: Re: Physically based rendering
Date: 26 Jun 2015 03:54:00
Message: <558d0518$1@news.povray.org>
On 25-6-2015 20:00, And wrote:
> Just like the opinion clipka have answered you the other day, an emission sphere
> in the sky is too small to render. I always use the parallel light to
> simulate the sun light and it is very convenient. If you would like to place a
> white look-like object, the sun's color should like this: rgb<1,1,1>*10000.
> Is a very large quantity.
>
>

Depending on the scene, the multiplicator used can be less than that. In 
my experiments shown in p.b.i I used a multiplicator of 2 which works 
quite well. Much higher values overexpose the scene.

-- 
Thomas


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From: clipka
Subject: Re: Physically based rendering
Date: 26 Jun 2015 08:55:17
Message: <558d4bb5$1@news.povray.org>
Am 26.06.2015 um 09:53 schrieb Thomas de Groot:
> On 25-6-2015 20:00, And wrote:
>> Just like the opinion clipka have answered you the other day, an
>> emission sphere
>> in the sky is too small to render. I always use the parallel light to
>> simulate the sun light and it is very convenient. If you would like to
>> place a
>> white look-like object, the sun's color should like this:
>> rgb<1,1,1>*10000.
>> Is a very large quantity.
>>
>>
>
> Depending on the scene, the multiplicator used can be less than that. In
> my experiments shown in p.b.i I used a multiplicator of 2 which works
> quite well. Much higher values overexpose the scene.

Maybe there's a misundertanding here:

The multiplicator is needed on the looks_like object; the light_source 
brightness should stay the same if you don't use fade_power.


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From: Thomas de Groot
Subject: Re: Physically based rendering
Date: 26 Jun 2015 10:52:17
Message: <558d6721$1@news.povray.org>
On 26-6-2015 14:55, clipka wrote:
> Am 26.06.2015 um 09:53 schrieb Thomas de Groot:
>> On 25-6-2015 20:00, And wrote:
>>> Just like the opinion clipka have answered you the other day, an
>>> emission sphere
>>> in the sky is too small to render. I always use the parallel light to
>>> simulate the sun light and it is very convenient. If you would like to
>>> place a
>>> white look-like object, the sun's color should like this:
>>> rgb<1,1,1>*10000.
>>> Is a very large quantity.
>>>
>>>
>>
>> Depending on the scene, the multiplicator used can be less than that. In
>> my experiments shown in p.b.i I used a multiplicator of 2 which works
>> quite well. Much higher values overexpose the scene.
>
> Maybe there's a misundertanding here:
>
> The multiplicator is needed on the looks_like object; the light_source
> brightness should stay the same if you don't use fade_power.
>

True enough. THere was a misunderstanding though from my side (of 
course) as I had also added an emission to the looks_like object which 
it doesn't need in fact with And's suggestion.

-- 
Thomas


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From: clipka
Subject: Re: Physically based rendering
Date: 26 Jun 2015 11:27:10
Message: <558d6f4e$1@news.povray.org>
Am 26.06.2015 um 16:52 schrieb Thomas de Groot:
> On 26-6-2015 14:55, clipka wrote:
>> Am 26.06.2015 um 09:53 schrieb Thomas de Groot:
>>> On 25-6-2015 20:00, And wrote:
>>>> Just like the opinion clipka have answered you the other day, an
>>>> emission sphere
>>>> in the sky is too small to render. I always use the parallel light to
>>>> simulate the sun light and it is very convenient. If you would like to
>>>> place a
>>>> white look-like object, the sun's color should like this:
>>>> rgb<1,1,1>*10000.
>>>> Is a very large quantity.
>>>>
>>>>
>>>
>>> Depending on the scene, the multiplicator used can be less than that. In
>>> my experiments shown in p.b.i I used a multiplicator of 2 which works
>>> quite well. Much higher values overexpose the scene.
>>
>> Maybe there's a misundertanding here:
>>
>> The multiplicator is needed on the looks_like object; the light_source
>> brightness should stay the same if you don't use fade_power.
>>
>
> True enough. THere was a misunderstanding though from my side (of
> course) as I had also added an emission to the looks_like object which
> it doesn't need in fact with And's suggestion.

Um... a looks_like object should _always_ have a emission! Otherwise it 
won't look like what a light source would look like.


However, And has correctly hinted someplace else at conflict between 
different ways of simulating the same thing when using a "looks_like" 
object. A light source should only show up in one of the two ways of 
each of the following pairs:

- Classic diffuse illumination vs. radiosity: A "looks_like" object 
should always have "no_radiosity on" set, which unfortunately isn't the 
default. (Theoretically, an alternative would be to make the light 
source invisible for the sake of the "diffuse" component, but in 
practice that doesn't make any sense due to the vast differences in 
computational effort; if you want to go that far, just leave out the 
light source entirely and go with the "looks_like" object alone.)

- Specular highlights vs. reflections: A "looks_like" object should have 
"no_reflection on" set. An alternative would be to make the light source 
invisible for the sake of specular highlights, but POV-Ray doesn't 
support this at the moment (which puts me to shame, as I must admit).


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From: And
Subject: Re: Physically based rendering
Date: 27 Jun 2015 01:10:00
Message: <web.558e2f2618c52d498107bb350@news.povray.org>
Thomas de Groot <tho### [at] degrootorg> wrote:
> On 26-6-2015 14:55, clipka wrote:
> > Am 26.06.2015 um 09:53 schrieb Thomas de Groot:
> >> On 25-6-2015 20:00, And wrote:
> >>> Just like the opinion clipka have answered you the other day, an
> >>> emission sphere
> >>> in the sky is too small to render. I always use the parallel light to
> >>> simulate the sun light and it is very convenient. If you would like to
> >>> place a
> >>> white look-like object, the sun's color should like this:
> >>> rgb<1,1,1>*10000.
> >>> Is a very large quantity.
> >>>
> >>>
> >>
> >> Depending on the scene, the multiplicator used can be less than that. In
> >> my experiments shown in p.b.i I used a multiplicator of 2 which works
> >> quite well. Much higher values overexpose the scene.
> >
> > Maybe there's a misundertanding here:
> >
> > The multiplicator is needed on the looks_like object; the light_source
> > brightness should stay the same if you don't use fade_power.
> >
>
> True enough. THere was a misunderstanding though from my side (of
> course) as I had also added an emission to the looks_like object which
> it doesn't need in fact with And's suggestion.
>
> --
> Thomas

I saw the third one 'rsocp_uber_metallic.png' is just what my skill. I like it.
The color of sky is realism, too.


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From: And
Subject: Re: Physically based rendering
Date: 27 Jun 2015 01:20:03
Message: <web.558e317d18c52d498107bb350@news.povray.org>
clipka <ano### [at] anonymousorg> wrote:
>
> Um... a looks_like object should _always_ have a emission! Otherwise it
> won't look like what a light source would look like.
>
>
> However, And has correctly hinted someplace else at conflict between
> different ways of simulating the same thing when using a "looks_like"
> object. A light source should only show up in one of the two ways of
> each of the following pairs:
>
> - Classic diffuse illumination vs. radiosity: A "looks_like" object
> should always have "no_radiosity on" set, which unfortunately isn't the
> default. (Theoretically, an alternative would be to make the light
> source invisible for the sake of the "diffuse" component, but in
> practice that doesn't make any sense due to the vast differences in
> computational effort; if you want to go that far, just leave out the
> light source entirely and go with the "looks_like" object alone.)
>
> - Specular highlights vs. reflections: A "looks_like" object should have
> "no_reflection on" set. An alternative would be to make the light source
> invisible for the sake of specular highlights, but POV-Ray doesn't
> support this at the moment (which puts me to shame, as I must admit).

Thanks for the interpretation.


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From: And
Subject: Re: Physically based rendering
Date: 27 Jun 2015 01:25:00
Message: <web.558e335418c52d498107bb350@news.povray.org>
Thomas de Groot <tho### [at] degrootorg> wrote:
> On 26-6-2015 8:58, Stephen wrote:
> > On 26/06/2015 07:34, And wrote:
> >> "And" <49341109@ntnu.edu.tw> wrote:
> >>
> >> I'm very smart.!!
> >>
> >
> > LOL
> > You are too. :-)
> >
>
> Why do I feel depressed now? :-)
>
> --
> Thomas

giggle.


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From: scott
Subject: Re: Physically based rendering
Date: 2 Jul 2015 04:25:09
Message: <5594f565$1@news.povray.org>
> - Always use "fresnel on" for reflections (don't forget to specify
> "ior"), or "metallic on" where applicable, and always use 0.0 for the
> minimum reflection (or leave it out, specifying the maximum reflection
> only).

If you are using fresnel, is it valid (from a PBR point of view) to even 
scale the results using a maximum reflection other than 1?


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