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30 Jul 2024 18:10:14 EDT (-0400)
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From: Dan P
Subject: Re: Lighting
Date: 4 Feb 2004 21:58:08
Message: <4021b140$1@news.povray.org>
Oh, and I forgot about the table too! A little reflection there and a little
specular highlight and BAM (to steal from Emeril)!

#include "colors.inc"
#include "textures.inc"
#include "shapes.inc"


#declare SnakeWood =
texture {  /* Bottom wood-grain layer */
    pigment {
        wood
        turbulence 0.05
        color_map {
            [0.00 rgb <0.58, 0.45, 0.23>]
            [0.34 rgb <0.65, 0.45, 0.25>]
            [0.40 rgb <0.33, 0.23, 0.13>]
            [0.47 rgb <0.60, 0.40, 0.20>]
            [1.00 rgb <0.25, 0.15, 0.05>]
        }
    }
    finish {
        crand 0.02
        //ambient 0.32
        diffuse 0.63
        phong 0.2
        phong_size 10
    }
    normal { bumps 0.05 }
}
texture {     /* top layer, adds small dark spots */
    pigment {
        bozo
        color_map {
            [0.0 rgbt <1.00, 1.00, 1.00, 1.00>]
            [0.8 rgbt <1.00, 0.90, 0.80, 0.80>]
            [1.0 rgbt <0.30, 0.20, 0.10, 0.40>]
        }
    scale 0.25
    }
}


// New stuff -- DAP
light_source
{
  <60, 20, -50>
  color rgb <0.2, 0.25, 0.3>
  shadowless
}

sky_sphere
{
 pigment
 {
  wrinkles

  color_map
  {
   [0, rgb <0, 0, 0> ]
   [1, rgb <0.7, 0.6, 0.5> ]
  }

  scale <0.1, 0.1, 0.1>
 }
}






light_source {<-20, 20, 0> color White area_light  <5, 0, 0>, <0, 0, 5>, 11,
11 adaptive 1 jitter photons { refraction on reflection on } }

camera  {
        location <0,10,-25> look_at <0,0,0>
       }

//background { Black }//color <0.25,0.35,0.80> }
box     {
        <-1,-1,-1>,
        <1,1,1>
        texture {
                pigment { Red }
                }
        scale <2,2,2>
        rotate <0,-15,0>
        translate <2,1,10>
        }
box     {
        <-1,-1,-1>,
        <1,1,1>
        texture {
                pigment { Red }
                }
        scale <2,2,2>
        rotate <0,-16,0>
        translate <2,1,-9>
        }
cylinder{
        <-1,-1,-1>,
        <1,1,1>,
        1
        texture {
                pigment { White*2 }
                }
        scale <1,5,1>
        translate <-7,3,0>
        }

plane   { <0, 1, 0>, -0.001
        texture { SnakeWood }//pigment { checker pigment{Red},
pigment{White} } scale <10,10,10> rotate <0,43,0>}
        finish { specular 0.3 reflection 0.15 }
        }

#declare Point1 = <-10,1,10>;
#declare Point2 = <-10,1,0>;
#declare Point3 = <-10,1,-10>;
#declare Point4 = <0,1,-10>;
#declare Point5 = <10,1,-10>;
#declare Point6 = <15,1,2>;     //<10,1,0>;
#declare Point7 = <10,1,2>;    //<10,1,10>;
#declare Point8 = <0,1,10>;
#declare Point9 = <-14,1,12>; //<-10,1,10>;
#declare Point10 = <-10,1,0>;
#declare Point11 = <-10,1,-10>;

merge {
// outside of the puddle
sphere_sweep {
        cubic_spline
        11,
        Point1,1
        Point2,1
        Point3,1
        Point4,1
        Point5,1
        Point6,1
        Point7,1
        Point8,1
        Point9,1
        Point10,1
        Point11,1
        }

// inside of the puddle
prism {
    cubic_spline
    0, // sweep the following shape from here ...
    2, // ... up through here
    11, // the number of points making up the shape ...
        <Point1.x,Point1.z>,
        <Point2.x,Point2.z>,
        <Point3.x,Point3.z>,
        <Point4.x,Point4.z>,
        <Point5.x,Point5.z>,
        <Point6.x,Point6.z>,
        <Point7.x,Point7.z>,
        <Point8.x,Point8.z>,
        <Point9.x,Point9.z>,
        <Point10.x,Point10.z>,
        <Point11.x,Point11.z>
  }

        hollow
        texture {
                pigment {
                 rgbft <0.2, 0.16, 0, 0.8, 0.3>
                        //Clear // rgbt <0.858824,0.576471,0.439216>
                        }
                finish  {
                        reflection { 0.1,0.9 }
                        specular 0.5
                        }
                }
        interior        {
                        ior Water_Ior
                        }
        translate <0,-1.5,0>

 }


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From: Phil Cook
Subject: Re: Lighting
Date: 5 Feb 2004 06:20:00
Message: <opr2v9spm2p4ukzs@news.povray.org>
On Wed, 4 Feb 2004 16:34:56 -0000, Felbrigg <som### [at] microsoftcom> wrote:

> I've already posted a couple of images in the binaries.images section 
> namely
> "Cactus halo" and "Rain Drops" but if you would like to help me out, look
> there for one I've just posted called "Spilled Liquid" (Source included)
> This is an example of an almost but never quite right table top image.  
> If
> you can give me some tips on how to improve it, adjusting the lighting 
> etc I
> would be very grateful.
>
> Thanks.
>
>
> "Dan P" <dan### [at] yahoocom> wrote in message
> news:402117ff$1@news.povray.org...
>> Also, I find that using multiple light sources can go along way. Throw a
>> bright, shadowless indigo light at a different location (color rgb <0.8,
>> 0.9, 1> for example) and it will add a lot of depth. In reality, there 
>> is
>> rarely only one light source and you don't always need radiosity to get 
>> a
>> realistic effect. Look at a book cover once: often, you'll see that one
> side
>> of the face is lit with a yellowish light and the other side is light 
>> with
>> an indigo/cyan light. It makes a really neat effect.
>>
>> If you're willing, we're interested in seeing your work if you post it 
>> on
> a
>> site and helping you out that way too. There are lots of tricks of light
>> (pun intended) that can turn a blah scene into something amazing.

If you are still interested google "three point lighting"

http://www.3drender.com/light/3point.html

This link's quite basic but still worth a look at, more advanced stuff is 
also available on google

Hope it's of use to you.

--
Phil

-- 
All thoughts and comments are my own unless otherwise stated and I am 
happy to be proven wrong.


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From: Stephen McAvoy
Subject: Re: Lighting
Date: 5 Feb 2004 06:55:54
Message: <mpb420h1n2f5c13n3f0k9u9liqsephasdu@4ax.com>
On Wed, 4 Feb 2004 16:34:56 -0000, "Felbrigg" <som### [at] microsoftcom> wrote:

> If you can give me some tips on how to improve it, adjusting the lighting etc I
>would be very grateful.

Interesting reading here. Again basic but that is what you need to start out
with. 

http://www.cybercollege.com/indexall.htm

Lighting starts here
http://www.cybercollege.com/tvp027.htm


Regards
        Stephen


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From: Felbrigg
Subject: Re: Lighting
Date: 5 Feb 2004 07:14:42
Message: <402233b2$1@news.povray.org>
Where to begin?

The second coloured light, had me foxed at first, I couldn't see the
difference until I opened "before" and "after" side by side in paint shop.
It does improove the scene - Good Tip.

Specular highlighting, hmm,  rendered it despite my misgivings and at first
I thought I was right and you were wrong, again, side by side in Paint shop
and WOW, it is better, you were right.  It gives better definition to the
spill, allowing the liquids edge to look truely curved.

Coffee colouring, nice.  I'd tried rgbf and rgbt but you hit me with a new
one there, rgbft, again WOW.

Reflection and specular on the table, didn't see that one coming.  Took me a
while to see a difference, It seems to have made the light source have a
sharper definition on the table top.  Is that it?  Can you give me any
pointers as to why you suggested this, what am I missing?

I'm struggling with this lighting stuff,  so much of it seems
counter-intuitive to me.  Your pointers have been really eye - opening.
Thanks very much.

P.S. I see from your other posts your a 'C' man.  Scary stuff, the nearest
I've got to that is C# what I call "the laymans C".  Do you know if it
possible to use C# to fire off PovRay like (i think) Moray does.  I've often
thought about writing a Win32 app to automate some animation experiments,
thus freeing me from the clock and frames constraints.


"Dan P" <dan### [at] yahoocom> wrote in message
news:4021b140$1@news.povray.org...
> Oh, and I forgot about the table too! A little reflection there and a
little
> specular highlight and BAM (to steal from Emeril)!
>
> #include "colors.inc"
> #include "textures.inc"
> #include "shapes.inc"
>
>
> #declare SnakeWood =
> texture {  /* Bottom wood-grain layer */
>     pigment {
>         wood
>         turbulence 0.05
>         color_map {
>             [0.00 rgb <0.58, 0.45, 0.23>]
>             [0.34 rgb <0.65, 0.45, 0.25>]
>             [0.40 rgb <0.33, 0.23, 0.13>]
>             [0.47 rgb <0.60, 0.40, 0.20>]
>             [1.00 rgb <0.25, 0.15, 0.05>]
>         }
>     }
>     finish {
>         crand 0.02
>         //ambient 0.32
>         diffuse 0.63
>         phong 0.2
>         phong_size 10
>     }
>     normal { bumps 0.05 }
> }
> texture {     /* top layer, adds small dark spots */
>     pigment {
>         bozo
>         color_map {
>             [0.0 rgbt <1.00, 1.00, 1.00, 1.00>]
>             [0.8 rgbt <1.00, 0.90, 0.80, 0.80>]
>             [1.0 rgbt <0.30, 0.20, 0.10, 0.40>]
>         }
>     scale 0.25
>     }
> }
>
>
> // New stuff -- DAP
> light_source
> {
>   <60, 20, -50>
>   color rgb <0.2, 0.25, 0.3>
>   shadowless
> }
>
> sky_sphere
> {
>  pigment
>  {
>   wrinkles
>
>   color_map
>   {
>    [0, rgb <0, 0, 0> ]
>    [1, rgb <0.7, 0.6, 0.5> ]
>   }
>
>   scale <0.1, 0.1, 0.1>
>  }
> }
>
>
>
>
>
>
> light_source {<-20, 20, 0> color White area_light  <5, 0, 0>, <0, 0, 5>,
11,
> 11 adaptive 1 jitter photons { refraction on reflection on } }
>
> camera  {
>         location <0,10,-25> look_at <0,0,0>
>        }
>
> //background { Black }//color <0.25,0.35,0.80> }
> box     {
>         <-1,-1,-1>,
>         <1,1,1>
>         texture {
>                 pigment { Red }
>                 }
>         scale <2,2,2>
>         rotate <0,-15,0>
>         translate <2,1,10>
>         }
> box     {
>         <-1,-1,-1>,
>         <1,1,1>
>         texture {
>                 pigment { Red }
>                 }
>         scale <2,2,2>
>         rotate <0,-16,0>
>         translate <2,1,-9>
>         }
> cylinder{
>         <-1,-1,-1>,
>         <1,1,1>,
>         1
>         texture {
>                 pigment { White*2 }
>                 }
>         scale <1,5,1>
>         translate <-7,3,0>
>         }
>
> plane   { <0, 1, 0>, -0.001
>         texture { SnakeWood }//pigment { checker pigment{Red},
> pigment{White} } scale <10,10,10> rotate <0,43,0>}
>         finish { specular 0.3 reflection 0.15 }
>         }
>
> #declare Point1 = <-10,1,10>;
> #declare Point2 = <-10,1,0>;
> #declare Point3 = <-10,1,-10>;
> #declare Point4 = <0,1,-10>;
> #declare Point5 = <10,1,-10>;
> #declare Point6 = <15,1,2>;     //<10,1,0>;
> #declare Point7 = <10,1,2>;    //<10,1,10>;
> #declare Point8 = <0,1,10>;
> #declare Point9 = <-14,1,12>; //<-10,1,10>;
> #declare Point10 = <-10,1,0>;
> #declare Point11 = <-10,1,-10>;
>
> merge {
> // outside of the puddle
> sphere_sweep {
>         cubic_spline
>         11,
>         Point1,1
>         Point2,1
>         Point3,1
>         Point4,1
>         Point5,1
>         Point6,1
>         Point7,1
>         Point8,1
>         Point9,1
>         Point10,1
>         Point11,1
>         }
>
> // inside of the puddle
> prism {
>     cubic_spline
>     0, // sweep the following shape from here ...
>     2, // ... up through here
>     11, // the number of points making up the shape ...
>         <Point1.x,Point1.z>,
>         <Point2.x,Point2.z>,
>         <Point3.x,Point3.z>,
>         <Point4.x,Point4.z>,
>         <Point5.x,Point5.z>,
>         <Point6.x,Point6.z>,
>         <Point7.x,Point7.z>,
>         <Point8.x,Point8.z>,
>         <Point9.x,Point9.z>,
>         <Point10.x,Point10.z>,
>         <Point11.x,Point11.z>
>   }
>
>         hollow
>         texture {
>                 pigment {
>                  rgbft <0.2, 0.16, 0, 0.8, 0.3>
>                         //Clear // rgbt <0.858824,0.576471,0.439216>
>                         }
>                 finish  {
>                         reflection { 0.1,0.9 }
>                         specular 0.5
>                         }
>                 }
>         interior        {
>                         ior Water_Ior
>                         }
>         translate <0,-1.5,0>
>
>  }
>
>


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From: Christopher James Huff
Subject: Re: Lighting
Date: 5 Feb 2004 09:05:48
Message: <cjameshuff-B435B0.09055805022004@news.povray.org>
In article <402233b2$1@news.povray.org>,
 "Felbrigg" <som### [at] microsoftcom> wrote:

> The second coloured light, had me foxed at first, I couldn't see the
> difference until I opened "before" and "after" side by side in paint shop.

You'll learn to see this kind of thing more easily...just takes time and 
practice. Before long you won't be able to stop. YKYBRTTLW...


> Coffee colouring, nice.  I'd tried rgbf and rgbt but you hit me with a new
> one there, rgbft, again WOW.

Bad advice, IMO. The most realistic method that I've found is to use an 
entirely transparent texture (a pigment with rgbf 1), and media or 
interior attenuation for coloring. A colored transparent texture is like 
a thin film covering the coffee, but this simulates color throughout the 
body of the coffee.

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: <chr### [at] tagpovrayorg>
http://tag.povray.org/


Post a reply to this message

From: Dan P
Subject: Re: Lighting
Date: 6 Feb 2004 00:01:17
Message: <40231f9d$1@news.povray.org>
"Felbrigg" <som### [at] microsoftcom> wrote in message
news:402233b2$1@news.povray.org...
> Where to begin?
>
> The second coloured light, had me foxed at first, I couldn't see the
> difference until I opened "before" and "after" side by side in paint shop.
> It does improove the scene - Good Tip.

Thanks :-)

> Specular highlighting, hmm,  rendered it despite my misgivings and at
first
> I thought I was right and you were wrong, again, side by side in Paint
shop
> and WOW, it is better, you were right.  It gives better definition to the
> spill, allowing the liquids edge to look truely curved.

The higher the specular value, the more defined the highlight becomes.

> Coffee colouring, nice.  I'd tried rgbf and rgbt but you hit me with a new
> one there, rgbft, again WOW.
>
> Reflection and specular on the table, didn't see that one coming.  Took me
a
> while to see a difference, It seems to have made the light source have a
> sharper definition on the table top.  Is that it?  Can you give me any
> pointers as to why you suggested this, what am I missing?

It added a highlight to the table. The trick is that it makes the surface
look less uniform.

> I'm struggling with this lighting stuff,  so much of it seems
> counter-intuitive to me.  Your pointers have been really eye - opening.
> Thanks very much.

No problem! :-)

> P.S. I see from your other posts your a 'C' man.  Scary stuff, the nearest
> I've got to that is C# what I call "the laymans C".  Do you know if it
> possible to use C# to fire off PovRay like (i think) Moray does.  I've
often
> thought about writing a Win32 app to automate some animation experiments,
> thus freeing me from the clock and frames constraints.

Sure, you can fire off POV-ray with pretty much any language -- it's just a
matter of running pvengine.exe. My job allows me to do a lot of different
programming languages so I get a really different perspective sometimes.

I'm glad I was able to help and I really liked that scene! It would be the
perfect scene for a tutorial too.


Post a reply to this message

From: Dan P
Subject: Re: Lighting
Date: 6 Feb 2004 00:05:47
Message: <402320ab$1@news.povray.org>
"Christopher James Huff" <cja### [at] earthlinknet> wrote in message
news:cjameshuff-B435B0.09055805022004@news.povray.org...
>
> Bad advice, IMO. The most realistic method that I've found is to use an
> entirely transparent texture (a pigment with rgbf 1), and media or
> interior attenuation for coloring. A colored transparent texture is like
> a thin film covering the coffee, but this simulates color throughout the
> body of the coffee.

Thanks for the tip! It makes sense to make the actual liquid itself the
color and not just the skin around the outside. The reason I did it that way
was for speed, really; I find interior media to really slow down my
renderings and I like to do a lot of animation with motion blurs so I throw
out a lot of frames. However, for a still-shot, I think Chris is definitely
right here -- it'll make the light interact with the coffee better.


Post a reply to this message

From: Christopher James Huff
Subject: Re: Lighting
Date: 6 Feb 2004 10:27:27
Message: <cjameshuff-5E6769.10274006022004@news.povray.org>
In article <402320ab$1@news.povray.org>,
 "Dan P" <dan### [at] yahoocom> wrote:

> Thanks for the tip! It makes sense to make the actual liquid itself the
> color and not just the skin around the outside. The reason I did it that way
> was for speed, really; I find interior media to really slow down my
> renderings and I like to do a lot of animation with motion blurs so I throw
> out a lot of frames. However, for a still-shot, I think Chris is definitely
> right here -- it'll make the light interact with the coffee better.

Absorbing media will have a much lesser impact on speed than scattering 
media, especially when there's no variation in density to sample. And 
interior attenuation is very fast, because it never has to handle 
variable density and can use a much simpler method to compute the 
attenuation.

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: <chr### [at] tagpovrayorg>
http://tag.povray.org/


Post a reply to this message

From: Christopher James Huff
Subject: Re: Lighting
Date: 6 Feb 2004 10:36:27
Message: <cjameshuff-886A52.10363906022004@news.povray.org>
In article <40231f9d$1@news.povray.org>,
 "Dan P" <dan### [at] yahoocom> wrote:

> The higher the specular value, the more defined the highlight becomes.

The higher the specular value, the brighter it becomes, specular 1 
giving full brightness at the brightest points of the highlight. The 
"roughness" parameter controls the "sharpness" of the highlight...small 
values will give a more hard, highly polished look.

-- 
Christopher James Huff <cja### [at] earthlinknet>
http://home.earthlink.net/~cjameshuff/
POV-Ray TAG: <chr### [at] tagpovrayorg>
http://tag.povray.org/


Post a reply to this message

From: Dan P
Subject: Re: Lighting
Date: 6 Feb 2004 11:15:52
Message: <4023bdb8@news.povray.org>
"Christopher James Huff" <cja### [at] earthlinknet> wrote in message
news:cjameshuff-5E6769.10274006022004@news.povray.org...
> In article <402320ab$1@news.povray.org>,
>  "Dan P" <dan### [at] yahoocom> wrote:
>
> Absorbing media will have a much lesser impact on speed than scattering
> media, especially when there's no variation in density to sample. And
> interior attenuation is very fast, because it never has to handle
> variable density and can use a much simpler method to compute the
> attenuation.

Oh, I see what you mean. I was basing that perception on scattering media,
not absorbing media. I'm really glad I've been reading these newsgroups -- 
it's been having a very positive impact on my scenes. Thanks, Chris!!!


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