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25 Nov 2024 15:36:10 EST (-0500)
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From: Norbert Kern
Subject: Re: Looking for Water
Date: 3 Aug 2015 09:45:01
Message: <web.55bf700579f62d149640c760@news.povray.org>
"Anthony D. Baye" <Sha### [at] spamnomorehotmailcom> wrote:
> I need a water material that looks good under multiple light sources but doesn't
> bog down when I render it with radiosity.
>
> The water in my scene is taking forever to render, and I've disabled everything
> but the normal pattern.
>
> Part of the problem might be a low aa threshold combined with a small focal
> blur, but the rest of the scene renders acceptably quickly.



A reaonable fast water material is the one from the povray benchmark:

#declare RMF = function {f_ridged_mf (x,y,z, 0.07, 2.2, 7, 0.6, 0.9, 1)}

#declare M_Watx4 =
material {
        texture {
                pigment {color rgbt <0.21,0.2,0.3,0.96>}
                finish {
                        diffuse 0
                        ambient 0
                        reflection {0.1, 0.95 fresnel on exponent 0.8}
                        conserve_energy
                        specular 0.1*10
                        roughness 0.007
                        metallic 0+0.5
                }
                normal {
                        function {RMF (x,y,z)} 0.2
                        scale 0.07
                }
        }
        interior {
                ior 1.31
                fade_distance 0.8
                fade_power 1001
                fade_color <0.02,0.2,0.06>
        }
}

Imho the diffuse value of 0 is very important.
If it seems too dark, rising the fade_color value is helpful.


Norbert


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From: clipka
Subject: Re: Looking for Water
Date: 3 Aug 2015 13:13:57
Message: <55bfa155$1@news.povray.org>
Am 03.08.2015 um 15:43 schrieb Norbert Kern:

> A reaonable fast water material is the one from the povray benchmark:
>
> #declare RMF = function {f_ridged_mf (x,y,z, 0.07, 2.2, 7, 0.6, 0.9, 1)}
>
> #declare M_Watx4 =
> material {
>          texture {
>                  pigment {color rgbt <0.21,0.2,0.3,0.96>}

In theory it should be "rgbt <0.0,0.0,0.0, 1.0>"

>                  finish {
>                          diffuse 0
>                          ambient 0

Those two are important indeed.

>                          reflection {0.1, 0.95 fresnel on exponent 0.8}

At least theoretically that should be "reflection { 1.0 fresnel on }"

>                          conserve_energy

Very important.

>                          specular 0.1*10
>                          roughness 0.007

To better match the reflection, it should be "specular albedo 1.0" 
(provided you go for the theoretical value).

If you use a new (semi-official) version of POV-Ray, placing an 
additional "fresnel on" here would also help for more realism.

>                          metallic 0+0.5

In theory it shouldn't be metallic.

>                  }
>                  normal {
>                          function {RMF (x,y,z)} 0.2
>                          scale 0.07
>                  }
>          }
>          interior {
>                  ior 1.31
>                  fade_distance 0.8
>                  fade_power 1001
>                  fade_color <0.02,0.2,0.06>

For realism, you should also have some scattering component (read: 
scattering media) in the interior.


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From: Alain
Subject: Re: Looking for Water
Date: 3 Aug 2015 13:16:06
Message: <55bfa1d6$1@news.povray.org>
Le 15-08-03 03:16, Le_Forgeron a écrit :
> Le 03/08/2015 05:27, Anthony D. Baye a écrit :
>> I need a water material that looks good under multiple light sources
>> but doesn't
>> bog down when I render it with radiosity.
>>
>> The water in my scene is taking forever to render, and I've disabled
>> everything
>> but the normal pattern.
>>
>> Part of the problem might be a low aa threshold combined with a small
>> focal
>> blur, but the rest of the scene renders acceptably quickly.
>>
>> I'd appreciate any help.
>>
>> Regards,
>> A.D.B.
>>
>>
> A bit more context please: is it water for indoor (such as inside tube,
> glass, bottle) or outdoor (and kind of latitude: the sea of polynesia is
> far different from the waves of scotland, same water, yet not the same
> final colour).
>
> Maybe also limiting the trace level, if it does not impact too much the
> result, might provided a speed up. Default is 5, which in 3.7 counts for
> the reflexion but not the transmission when the ior does not change. If
> you have a kind of echo chamber (two partially reflecting surfaces on
> each other) it might skyrocket the number of ray to launch, and the
> render time. Tunning down the max_trace_level can reduces that echo
> effect (but might impact realism if it's an important aspect of your
> scene).
>
> Are you using media in your water ? why is there a normal pattern ?
> (what is the normal pattern in use ? can it be simplified or removed ?)
>
>

I often find it beter to increase adc_bailout than reduce max_trace_level.


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From: Nekar Xenos
Subject: Re: Looking for Water
Date: 3 Aug 2015 14:33:20
Message: <op.x2s1trcqufxv4h@xena>
On Mon, 03 Aug 2015 05:27:58 +0200, Anthony D. Baye  
<Sha### [at] spamnomorehotmailcom> wrote:

> I need a water material that looks good under multiple light sources but  
> doesn't
> bog down when I render it with radiosity.
>
> The water in my scene is taking forever to render, and I've disabled  
> everything
> but the normal pattern.
>
> Part of the problem might be a low aa threshold combined with a small  
> focal
> blur, but the rest of the scene renders acceptably quickly.
>
> I'd appreciate any help.
>
> Regards,
> A.D.B.
>
>

Have you tried adding no_radiosity to the water?

-- 
-Nekar Xenos-


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From: Anthony D  Baye
Subject: Re: Looking for Water
Date: 3 Aug 2015 18:05:00
Message: <web.55bfe57579f62d142aaea5cb0@news.povray.org>
Le_Forgeron <lef### [at] freefr> wrote:
> Le 03/08/2015 05:27, Anthony D. Baye a écrit :
> > I need a water material that looks good under multiple light sources but doesn't
> > bog down when I render it with radiosity.
> >
> > The water in my scene is taking forever to render, and I've disabled everything
> > but the normal pattern.
> >
> > Part of the problem might be a low aa threshold combined with a small focal
> > blur, but the rest of the scene renders acceptably quickly.
> >
> > I'd appreciate any help.
> >
> > Regards,
> > A.D.B.
> >
> >
> A bit more context please: is it water for indoor (such as inside tube,
> glass, bottle) or outdoor (and kind of latitude: the sea of polynesia is
> far different from the waves of scotland, same water, yet not the same
> final colour).
>
Right.  Because of the salts dissolved in the water.
That said: It's nothing special.

pigment { rgbft <1.000, 1.000, 1.000, 1.000, 0.618> }
finish {
    diffuse 0.3
    specular 0.8
    reflection { 0.3, 1 falloff 5 }
    conserve_energy
    }
normal {
    function {
        f_ridged_mf(x,y,z, 0.1, 3.0, 7.0, 0.7, 0.7, 2)
        } 0.3
    scale <4.68, 3.2, 4.68>/12
    }
interior {
    ior 1.33
    fade_distance 3
    fade_power 2
    fade_color rgb <0.235, 0.318, 0.618>
    dispersion 1.016
    dispersion_samples 10
    }

it's intended to be indoors, but may be lighted with external (natural) light
sources.  At the moment, I have six light sources surrounding it.

I used a normal as a substitute for actual geometry (Originally, I was using an
isosurface)

my trace level is default.

I tried commenting out the interior and the finish, to no avail, so either it's
the normal, or a combination of other things.

@Nekar
>
> Have you tried adding no_radiosity to the water?
>
> --
> -Nekar Xenos-

it doesn't matter.  The water takes forever to render even with radiosity turned
off.

Regards,
A.D.B.


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From: Bald Eagle
Subject: Re: Looking for Water
Date: 3 Aug 2015 21:25:05
Message: <web.55c0135079f62d145e7df57c0@news.povray.org>
"Anthony D. Baye" <Sha### [at] spamnomorehotmailcom> wrote:

> it's intended to be indoors, but may be lighted with external (natural) light
> sources.  At the moment, I have six light sources surrounding it.

I'm going to guess that there's your big problem.  Have you tried cutting out
some of the lights and seeing if you get a proportional increase in speed?  In
my experience, multiple lights are bad enough - once you have reflection and
transparency, things get S-L-O-W.


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From: Nekar Xenos
Subject: Re: Looking for Water
Date: 3 Aug 2015 22:27:51
Message: <op.x2tnsmyzufxv4h@xena>
On Tue, 04 Aug 2015 00:04:37 +0200, Anthony D. Baye  

<Sha### [at] spamnomorehotmailcom> wrote:

> Le_Forgeron <lef### [at] freefr> wrote:
>> Le 03/08/2015 05:27, Anthony D. Baye a écrit :
>> > I need a water material that looks good under multiple light source
s  

>> but doesn't
>> > bog down when I render it with radiosity.
>> >
>> > The water in my scene is taking forever to render, and I've disable
d  

>> everything
>> > but the normal pattern.
>> >
>> > Part of the problem might be a low aa threshold combined with a sma
ll  

>> focal
>> > blur, but the rest of the scene renders acceptably quickly.
>> >
>> > I'd appreciate any help.
>> >
>> > Regards,
>> > A.D.B.
>> >
>> >
>> A bit more context please: is it water for indoor (such as inside tub
e,
>> glass, bottle) or outdoor (and kind of latitude: the sea of polynesia
 is
>> far different from the waves of scotland, same water, yet not the sam
e
>> final colour).
>>
> Right.  Because of the salts dissolved in the water.
> That said: It's nothing special.
>
> pigment { rgbft <1.000, 1.000, 1.000, 1.000, 0.618> }
> finish {
>     diffuse 0.3
>     specular 0.8
>     reflection { 0.3, 1 falloff 5 }
>     conserve_energy
>     }
> normal {
>     function {
>         f_ridged_mf(x,y,z, 0.1, 3.0, 7.0, 0.7, 0.7, 2)
>         } 0.3
>     scale <4.68, 3.2, 4.68>/12
>     }
> interior {
>     ior 1.33
>     fade_distance 3
>     fade_power 2
>     fade_color rgb <0.235, 0.318, 0.618>
>     dispersion 1.016
>     dispersion_samples 10
>     }
>
> it's intended to be indoors, but may be lighted with external (natural
)  

> light
> sources.  At the moment, I have six light sources surrounding it.
>
> I used a normal as a substitute for actual geometry (Originally, I was
  

> using an
> isosurface)
>
> my trace level is default.
>
> I tried commenting out the interior and the finish, to no avail, so  

> either it's
> the normal, or a combination of other things.
>
> @Nekar
>>
>> Have you tried adding no_radiosity to the water?
>>
>> --
>> -Nekar Xenos-
>
> it doesn't matter.  The water takes forever to render even with  

> radiosity turned
> off.
>
> Regards,
> A.D.B.
>
>

Maybe you could try and render the scene without the water and your focu
s  

objects as a spherical hdri. Then use that image mapped to a sphere as i
n  

the old MegaPov example
http://megapov.inetart.net/manual-1.1/tutorials_hdri.html

-- 

-Nekar Xenos-


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From: Norbert Kern
Subject: Re: Looking for Water
Date: 4 Aug 2015 04:10:00
Message: <web.55c0721079f62d149640c760@news.povray.org>
"Anthony D. Baye" <Sha### [at] spamnomorehotmailcom> wrote:

> pigment { rgbft <1.000, 1.000, 1.000, 1.000, 0.618> }
> finish {
>     diffuse 0.3
>     specular 0.8
>     reflection { 0.3, 1 falloff 5 }
>     conserve_energy
>     }
> normal {
>     function {
>         f_ridged_mf(x,y,z, 0.1, 3.0, 7.0, 0.7, 0.7, 2)
>         } 0.3
>     scale <4.68, 3.2, 4.68>/12
>     }
> interior {
>     ior 1.33
>     fade_distance 3
>     fade_power 2
>     fade_color rgb <0.235, 0.318, 0.618>
>     dispersion 1.016
>     dispersion_samples 10
>     }

I see some issues like a transparency of 161.8 %, but this does not slow your
render down, at least it doesn't in my standard setup.
Even turning fresnel on or diffuse 0 doesn't have any effect on render time.
But turning dispersion off decreased render time to less than 20 %.

Norbert


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From: Thomas de Groot
Subject: Re: Looking for Water
Date: 16 Aug 2015 07:42:19
Message: <55d0771b$1@news.povray.org>
Sorry for the delay.

I almost always use the following material for (outside) water which 
renders reasonably fast and looks good. See my Not Islay scene in p.b.i.

   material {
     texture {
       pigment {rgbft <0,0,0,1,1>}
       finish {
         conserve_energy
         diffuse albedo 0.2
         specular albedo 0.2
         roughness 0.001
         ambient 0
         reflection {
           0.0, 0.2
           fresnel on
           metallic off
           #if (Uber)
             roughness 0.001
           #end
         }
       }
       normal {crackle 0.15 scale <0.45*4,0.25,0.25>*4 turbulence 0.5 }
       //normal {ripples 0.15 scale <0.45,0.25,0.25>*2 turbulence 0.5 }
     }
     interior {
       ior 1.33
       media {
         method 3
         absorption 0.3
         density {rgb 1/FD}
       }
       media {
         method 3
         samples 100
         jitter 0.5
         scattering {3, 0.05}
         density {
           granite
           color_map {
             [0.30 rgb <0.2, 0.2, 0.2>]
             [0.70 rgb <0.7, 0.7, 0.7>]
           }
           scale 1/2
           //warp {turbulence <6, 0.5, 2>}
           warp {turbulence <8, 2, 2>}
           scale 2
         }
       }
     }
   }


-- 
Thomas


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From: Thomas de Groot
Subject: Re: Looking for Water
Date: 16 Aug 2015 07:44:38
Message: <55d077a6@news.povray.org>
You need also this before using the material:

#declare Dist    = 10; 
//determines the depth transparency of the water column
#declare FD      = -(Dist/(6*25.4))/ln(0.58);	 
//fade distance (formula by Trevor Quayle)



-- 
Thomas


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