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From: Sun Tzu
Subject: POVing again (~170k)
Date: 28 Feb 2004 21:27:27
Message: <40414e0f@news.povray.org>
I haven't POVed for about 8 months and just picked it up again.  Close to a
year ago I posted an earlier version of this image.  I did more work on it
and then left it alone for several months.  The cheese got me frustrated
because I couldn't come up with something that looked satisfactory to me.
Also the picture is far to 'sterile' looking, but I'm not sure how to make
things look dirty or worn.    For example I'd like to have some cheese
residue on the knife, but haven't a clue how to accomplish that.   I'd
appreciate any suggestions.  Thanks.


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From: Dan P
Subject: Re: POVing again (~170k)
Date: 28 Feb 2004 22:22:00
Message: <40415ad8$1@news.povray.org>
"Sun Tzu" <sun### [at] nospamhotmailcom> wrote in message
news:40414e0f@news.povray.org...
> I haven't POVed for about 8 months and just picked it up again.  Close to
a
> year ago I posted an earlier version of this image.  I did more work on it
> and then left it alone for several months.  The cheese got me frustrated
> because I couldn't come up with something that looked satisfactory to me.
> Also the picture is far to 'sterile' looking, but I'm not sure how to make
> things look dirty or worn.    For example I'd like to have some cheese
> residue on the knife, but haven't a clue how to accomplish that.   I'd
> appreciate any suggestions.  Thanks.

Hello General Tzu! :-)

This image rocks. I found it easiest to make things look dirty (for example,
the label on the bottle) by averaging in a "wrinkles" pigment at a low
weight. Also, if you change the lighting -- perhaps even add some
atmospheric media -- it will look less sterile too. The trick is, just about
everything is sterile looking when clean, it is the /environment/ that
affects how real things look.

Oh, and the cheeze would be a great candidate for subsurface scattering too.
Lots of interior and media statements make things look really cool :-)


Post a reply to this message

From: Tek
Subject: Re: POVing again (~170k)
Date: 28 Feb 2004 23:10:42
Message: <40416642$1@news.povray.org>
On the whole that looks very realistic, the wine glass looks excellent, but the
cheese looks way to "hard". Like Daniel said it, should have sub-surface
scattering to really look like cheese.

I'd also suggest adding a few errors, the tiles in the background shouldn't be
perfectly aligned, and I think the gaps between them should be smaller, so they
nearly touch. Also the chopping board doesn't look right, I think it needs some
work on the wood texture (compare it to photos of real chopping boards), and
also it should have a few scratches on the top (these can just be faked with a
normal map and texture).

To get some cheese on the knife I would just modify the texture, so it has
streaks up it that are less shiny and cheese coloured. Perhaps support this with
a few small crumbs of cheese resting on the blade and on the surface next to it
(as if they fell off the knife when it was put down).

-- 
Tek
www.evilsuperbrain.com

"Sun Tzu" <sun### [at] nospamhotmailcom> wrote in message
news:40414e0f@news.povray.org...
> I haven't POVed for about 8 months and just picked it up again.  Close to a
> year ago I posted an earlier version of this image.  I did more work on it
> and then left it alone for several months.  The cheese got me frustrated
> because I couldn't come up with something that looked satisfactory to me.
> Also the picture is far to 'sterile' looking, but I'm not sure how to make
> things look dirty or worn.    For example I'd like to have some cheese
> residue on the knife, but haven't a clue how to accomplish that.   I'd
> appreciate any suggestions.  Thanks.
>
>
>
>
>
>


Post a reply to this message

From: Sun Tzu
Subject: Re: POVing again (~170k)
Date: 29 Feb 2004 01:14:45
Message: <40418355@news.povray.org>
Thanks for the suggestions.  I'm not that experienced with POV though so I'm
not sure exactly how to implement your ideas.   The materials always seem to
be one of my biggest problems.  I obviously need some tutoring in making
good materials.  How would I "average in a wrinkles pigment" on the label.
It is just an image texture:

texture
      {
         uv_mapping pigment
             {

               image_map
               {
                 gif   "eldwine9.gif"
                 interpolate 2
                }
                scale  <-0.18,0.35,0.2>
                rotate <0.0,  -47.0,  0.0>
                translate <0.0,80.0, 0.0>
             }
          finish
               {
                  ambient 0.0
                  diffuse 0.9
                  specular 0.2
                  roughness 0.2
               }
      }


Even more mysterious to me is the "subsurface scattering" that both you and
Tek suggest.  Here is the outside surface of the cheese, the 'sliced'
surfaces and bubbles are the same but without the normal.  How would I put
in subsurface scattering?

  texture {
    pigment {
                 color cheese_color
      }

    finish{
     ambient 0.2
     diffuse 0.7
      specular 0.15
      roughness 0.1
    }
    normal{
       agate 0.01
       scale <10,10,10>
    }
    }


Thanks.


"Dan P" <dan### [at] yahoocom> wrote in message
news:40415ad8$1@news.povray.org...
> "Sun Tzu" <sun### [at] nospamhotmailcom> wrote in message
> news:40414e0f@news.povray.org...
> > I haven't POVed for about 8 months and just picked it up again.  Close
to
> a
> > year ago I posted an earlier version of this image.  I did more work on
it
> > and then left it alone for several months.  The cheese got me frustrated
> > because I couldn't come up with something that looked satisfactory to
me.
> > Also the picture is far to 'sterile' looking, but I'm not sure how to
make
> > things look dirty or worn.    For example I'd like to have some cheese
> > residue on the knife, but haven't a clue how to accomplish that.   I'd
> > appreciate any suggestions.  Thanks.
>
> Hello General Tzu! :-)
>
> This image rocks. I found it easiest to make things look dirty (for
example,
> the label on the bottle) by averaging in a "wrinkles" pigment at a low
> weight. Also, if you change the lighting -- perhaps even add some
> atmospheric media -- it will look less sterile too. The trick is, just
about
> everything is sterile looking when clean, it is the /environment/ that
> affects how real things look.
>
> Oh, and the cheeze would be a great candidate for subsurface scattering
too.
> Lots of interior and media statements make things look really cool :-)
>
>


Post a reply to this message

From: Sun Tzu
Subject: Re: POVing again (~170k)
Date: 29 Feb 2004 01:28:03
Message: <40418673$1@news.povray.org>
Thank you for the suggestions.  Adding in some errors in the tiles is a good
idea.  I'll try and add a random error to the loop that places the tiles.
I'm not happy with the wood texture on the cutting board either, as I noted
in my reply to Daniel above, my material skills are rather weak.  I believe
that wood is just one of the standard textures from one of the standard inc
files that I tried to modify, but with little success.    I suspect I really
don't understand how the 'colormap' statement and multi layer materials
work.  Here's the material.  I'd appreciate any specific ideas you might
have for improving it.

 material {
   texture  // txt_75_1
   {
      pigment
      {
         wood
         color_map
         {
            [ 0.0     rgbft <0.6, 0.35, 0.2, 0.0, 0.0> ]
            [ 0.1     rgbft <0.6, 0.35, 0.2, 0.0, 0.0> ]
            [ 0.9     rgbft <0.9, 0.65, 0.3, 0.0, 0.0> ]
            [ 1.0     rgbft <0.6, 0.35, 0.2, 0.0, 0.0> ]
         }
         turbulence 0.05
         octaves 4
         ramp_wave
         scale  <0.15, 0.15, 1.0>
         rotate -90.0 * z

      }
      finish
      {
         ambient 0.2
         diffuse 0.5
         phong 0.4
         phong_size 16.0
         specular 0.1
         roughness 0.002
         reflection {0.02 fresnel on}

      }

   }
   interior{
         ior 1.5
      }
   texture  // txt_76_1
   {
      pigment
      {
         bozo
         color_map
         {
            [ 0.0     rgbft <0.9, 0.65, 0.3, 0.0, 0.0> ]
            [ 0.1     rgbft <0.9, 0.65, 0.3, 0.3, 0.0> ]
            [ 1.0     rgbft <1.0, 1.0, 1.0, 1.0, 0.0> ]
         }
         scale  <0.01, 0.01, 100000.0>
         rotate -90.0 * z
      }
      finish
      {
         ambient 0.2
         diffuse 0.5
         phong 0.4
         phong_size 16.0
         specular 0.1
         roughness 0.002
        reflection {0.02 fresnel on}
      }

   }
   interior{
         ior 1.5
      }
    rotate <0,90,90>
      scale <5,5,5>
   }


Thanks.


"Tek" <tek### [at] evilsuperbraincom> wrote in message
news:40416642$1@news.povray.org...
> On the whole that looks very realistic, the wine glass looks excellent,
but the
> cheese looks way to "hard". Like Daniel said it, should have sub-surface
> scattering to really look like cheese.
>
> I'd also suggest adding a few errors, the tiles in the background
shouldn't be
> perfectly aligned, and I think the gaps between them should be smaller, so
they
> nearly touch. Also the chopping board doesn't look right, I think it needs
some
> work on the wood texture (compare it to photos of real chopping boards),
and
> also it should have a few scratches on the top (these can just be faked
with a
> normal map and texture).
>
> To get some cheese on the knife I would just modify the texture, so it has
> streaks up it that are less shiny and cheese coloured. Perhaps support
this with
> a few small crumbs of cheese resting on the blade and on the surface next
to it
> (as if they fell off the knife when it was put down).
>
> -- 
> Tek
> www.evilsuperbrain.com
>
> "Sun Tzu" <sun### [at] nospamhotmailcom> wrote in message
> news:40414e0f@news.povray.org...
> > I haven't POVed for about 8 months and just picked it up again.  Close
to a
> > year ago I posted an earlier version of this image.  I did more work on
it
> > and then left it alone for several months.  The cheese got me frustrated
> > because I couldn't come up with something that looked satisfactory to
me.
> > Also the picture is far to 'sterile' looking, but I'm not sure how to
make
> > things look dirty or worn.    For example I'd like to have some cheese
> > residue on the knife, but haven't a clue how to accomplish that.   I'd
> > appreciate any suggestions.  Thanks.
> >
> >
> >
> >
> >
> >
>
>


Post a reply to this message

From: Dan P
Subject: Re: POVing again (~170k)
Date: 29 Feb 2004 01:51:10
Message: <40418bde@news.povray.org>
"Sun Tzu" <sun### [at] nospamhotmailcom> wrote in message
news:40418355@news.povray.org...
> Thanks for the suggestions.  I'm not that experienced with POV though so
I'm
> not sure exactly how to implement your ideas.   The materials always seem
to
> be one of my biggest problems.  I obviously need some tutoring in making
> good materials.  How would I "average in a wrinkles pigment" on the label.

Averaging pigments together is a very powerful too. To average pigments
together, use a "pigment_map" and a map type of "average". The following
code creates a plasma effect by averaging three pigments together. Note that
the "weight" of pigment for each is "1". Because there are three averaged
together, in order to get a value of "1.0" for full color, I have to use "3"
for the color value (3 times the amount of 1):

plane
{
 z, 1

 pigment
 {
  average

  pigment_map
  {
   [ 1  wrinkles

    color_map
    {
     [0 rgb <0, 0, 0> ]
     [1 rgb <3, 0, 0> ]
    }
   ]


   [ 1 wrinkles

    color_map
    {
     [0 rgb <0, 0, 0> ]
     [1 rgb <0, 3, 0> ]
    }

    translate 0.5
    ]

   [ 1 wrinkles

    color_map
    {
     [0 rgb <0, 0, 0> ]
     [1 rgb <0, 0, 3> ]
    }

    translate -0.5
    ]
  }
 }

 finish { ambient 1 }
}

> Even more mysterious to me is the "subsurface scattering" that both you
and
> Tek suggest.  Here is the outside surface of the cheese, the 'sliced'
> surfaces and bubbles are the same but without the normal.  How would I put
> in subsurface scattering?

I'd like to know too -- I haven't advanced to the point of being able to do
that. Tek knows more about that stuff than I. There is this really great
animation out there that shows subsurface scattering -- it was this marble
pyramid people were talking about a while back that was really something.
The code to that pyramid would really advance our understanding. Christopher
Huff is also amazingly knowledgeable about densities and the like.


Post a reply to this message

From: Tek
Subject: Re: POVing again (~170k)
Date: 29 Feb 2004 04:31:06
Message: <4041b15a$1@news.povray.org>
"Sun Tzu" <sun### [at] nospamhotmailcom> wrote in message
news:40418673$1@news.povray.org...
> I'd appreciate any specific ideas you might
> have for improving it.

WARNING - this is an incredibly long reply! But it sounded like you wanted some
tips on texturing so I've done my best:

Okay, well one thing stands out to me straight away: that's a very complicated
material, which is rather strange since we both agree it doesn't look so good.
My advice would always be keep the material very simple until you have nearly
the effect you like.

So, following that I'd suggest this much simpler version might be a good
starting point:
 texture {
  pigment {
   wood
   ramp_wave
   color_map
   {
    [0 rgb <0.6, 0.35, 0.2> ]
    [1 rgb <0.9, 0.65, 0.3> ]
   }
   turbulence 0.05
  }
  finish {
   diffuse .7
   ambient .3
  }
  rotate <30,30,0>
  scale 0.75
 }

Now, from this we can start looking at some more complex effects, firstly we can
change the colour map so it returns smoothly to it's starting point:
   color_map {
    [ 0.0 rgb <0.6, 0.35, 0.2> ]
    [ 0.8 rgb <0.9, 0.65, 0.3> ]
    [ 1.0 rgb <0.6, 0.35, 0.2> ]
   }
Note that the colour at 1 is now the same as the colour at 0. This will remove
the hard transition that occured before.

Now, before we add anything else I think we should decide whether the colours
look right. Personally I think they look far too dark for a chopping board, so
I'd try something a bit lighter and yellower:
    [ 0.0 rgb <0.9, 0.68, 0.4> ]
    [ 0.8 rgb <1, 0.8, 0.5> ]
    [ 1.0 rgb <0.9, 0.68, 0.4> ]

That's still not perfect so I recommend you spend a bit longer at this stage
until you get some colours you like.

Now, let's alter the pattern of the stripes. That 0.8 value in the colour map
can be changed to alter the way that the colours vary across the surface, also
the ramp_wave can be changed for one of pov's other types to create different
effects. Here's one example that I like but there's many other possibilities:

 pigment {
   wood
   poly_wave 2
   color_map
   {
    [ 0 rgb <0.9, 0.68, 0.4> ]
    [ .05 rgb <1, 0.8, 0.5> ]
    [ 1 rgb <0.9, 0.68, 0.4> ]
   }
   turbulence 0.05
 }

Now, lets look at the finish. The wood you had originally had a lot of
reflection and phong highlights, this suggests a varnished wood, but of course
chopping boards aren't varnished. So let's instead try to get a smooth but not
polished sheen to it. No reflections, since chopping boards aren't really
reflective, a soft and subtle highlight, and we'll tweak the brightness of the
material.

  finish {
   diffuse .5
   ambient .3
   brilliance 1.8
   specular .2 roughness .5 metallic 1
  }

There's 2 important things to notice here: the brilliance value alters the way
that the diffuse lighting looks, larger values give a more gradual falloff. And
the metallic specular highlight with a high roughness value behaves sort of like
a half-specular/half-diffuse light. It's a trick I used to create metallic
paint, but in this situation it's trying to fake the sheen that unvarnished wood
has.

Now, there's one final thing I'd like to do to this material, it's looking a bit
flat so let's give it a normal map:

  normal {
   wood
   poly_wave 2
   turbulence 0.05
   normal_map
   {
    [ 0 granite .05 scale .4 ]
    [ .05 radial .01 rotate x*90 sine_wave frequency 200 ]
    [ 1 granite .05 scale .4 ]
   }
  }

What I've done here is use the exact same basic pattern as the pigment, but
instead of blending 2 different colours I'm blending 2 normal patterns. There's
a radial one rotated to give perpendicular stripes across the rings in the wood,
and a granite texture to add noise to the darker patches of wood.

Finally, we can tidy this up so that we don't have to have 2 copies of this
pattern, like so:

 texture {
  pigment_pattern {
   //first let's take care of the wood pattern.
   wood
   poly_wave 2
   color_map
   {
    [ 0 rgb 0 ]
    [ .05 rgb 1 ]
    [ 1 rgb 0 ]
   }
   turbulence 0.05
  }

  //we have now defined a pattern so that
  //anything we map to 0 appears on the "dark" rings
  //and anything we map to zero appears on the light rings

  texture_map {
   [0
    //pattern for dark rings, a dark colour and noisy normal
    pigment { rgb <0.9, 0.68, 0.4> }
    finish {
     diffuse .6
     ambient .3
     brilliance 1.8
     specular .1 roughness .5 metallic .5
    }
    normal { granite .05 scale .4 }
   ]
   [1
    //pattern for light rings, a lighter colour and striped normal
    pigment { rgb <1, 0.8, 0.5> }
    finish {
     diffuse .6
     ambient .3
     brilliance 1.8
     specular .1 roughness .5 metallic .5
    }
    normal { radial .01 rotate x*90 sine_wave frequency 200 }
   ]
   }

  rotate <30,30,0>
  scale .75
  scale .3
 }

This technique isn't entirely necessary, but I find using pigment_patterns like
this can make it much easier to build complex textures.

I hope all of this helps!

-- 
Tek
www.evilsuperbrain.com


Post a reply to this message

From: Tek
Subject: Re: POVing again (~170k)
Date: 29 Feb 2004 04:32:29
Message: <4041b1ad@news.povray.org>
>   rotate <30,30,0>
>   scale .75
>   scale .3
>  }

whoops, ignore that last scale .3, that's just something I was using for my test
you don't need it.

-- 
Tek
www.evilsuperbrain.com


"Tek" <tek### [at] evilsuperbraincom> wrote in message
news:4041b15a$1@news.povray.org...
> "Sun Tzu" <sun### [at] nospamhotmailcom> wrote in message
> news:40418673$1@news.povray.org...
> > I'd appreciate any specific ideas you might
> > have for improving it.
>
> WARNING - this is an incredibly long reply! But it sounded like you wanted
some
> tips on texturing so I've done my best:
>
> Okay, well one thing stands out to me straight away: that's a very complicated
> material, which is rather strange since we both agree it doesn't look so good.
> My advice would always be keep the material very simple until you have nearly
> the effect you like.
>
> So, following that I'd suggest this much simpler version might be a good
> starting point:
>  texture {
>   pigment {
>    wood
>    ramp_wave
>    color_map
>    {
>     [0 rgb <0.6, 0.35, 0.2> ]
>     [1 rgb <0.9, 0.65, 0.3> ]
>    }
>    turbulence 0.05
>   }
>   finish {
>    diffuse .7
>    ambient .3
>   }
>   rotate <30,30,0>
>   scale 0.75
>  }
>
> Now, from this we can start looking at some more complex effects, firstly we
can
> change the colour map so it returns smoothly to it's starting point:
>    color_map {
>     [ 0.0 rgb <0.6, 0.35, 0.2> ]
>     [ 0.8 rgb <0.9, 0.65, 0.3> ]
>     [ 1.0 rgb <0.6, 0.35, 0.2> ]
>    }
> Note that the colour at 1 is now the same as the colour at 0. This will remove
> the hard transition that occured before.
>
> Now, before we add anything else I think we should decide whether the colours
> look right. Personally I think they look far too dark for a chopping board, so
> I'd try something a bit lighter and yellower:
>     [ 0.0 rgb <0.9, 0.68, 0.4> ]
>     [ 0.8 rgb <1, 0.8, 0.5> ]
>     [ 1.0 rgb <0.9, 0.68, 0.4> ]
>
> That's still not perfect so I recommend you spend a bit longer at this stage
> until you get some colours you like.
>
> Now, let's alter the pattern of the stripes. That 0.8 value in the colour map
> can be changed to alter the way that the colours vary across the surface, also
> the ramp_wave can be changed for one of pov's other types to create different
> effects. Here's one example that I like but there's many other possibilities:
>
>  pigment {
>    wood
>    poly_wave 2
>    color_map
>    {
>     [ 0 rgb <0.9, 0.68, 0.4> ]
>     [ .05 rgb <1, 0.8, 0.5> ]
>     [ 1 rgb <0.9, 0.68, 0.4> ]
>    }
>    turbulence 0.05
>  }
>
> Now, lets look at the finish. The wood you had originally had a lot of
> reflection and phong highlights, this suggests a varnished wood, but of course
> chopping boards aren't varnished. So let's instead try to get a smooth but not
> polished sheen to it. No reflections, since chopping boards aren't really
> reflective, a soft and subtle highlight, and we'll tweak the brightness of the
> material.
>
>   finish {
>    diffuse .5
>    ambient .3
>    brilliance 1.8
>    specular .2 roughness .5 metallic 1
>   }
>
> There's 2 important things to notice here: the brilliance value alters the way
> that the diffuse lighting looks, larger values give a more gradual falloff.
And
> the metallic specular highlight with a high roughness value behaves sort of
like
> a half-specular/half-diffuse light. It's a trick I used to create metallic
> paint, but in this situation it's trying to fake the sheen that unvarnished
wood
> has.
>
> Now, there's one final thing I'd like to do to this material, it's looking a
bit
> flat so let's give it a normal map:
>
>   normal {
>    wood
>    poly_wave 2
>    turbulence 0.05
>    normal_map
>    {
>     [ 0 granite .05 scale .4 ]
>     [ .05 radial .01 rotate x*90 sine_wave frequency 200 ]
>     [ 1 granite .05 scale .4 ]
>    }
>   }
>
> What I've done here is use the exact same basic pattern as the pigment, but
> instead of blending 2 different colours I'm blending 2 normal patterns.
There's
> a radial one rotated to give perpendicular stripes across the rings in the
wood,
> and a granite texture to add noise to the darker patches of wood.
>
> Finally, we can tidy this up so that we don't have to have 2 copies of this
> pattern, like so:
>
>  texture {
>   pigment_pattern {
>    //first let's take care of the wood pattern.
>    wood
>    poly_wave 2
>    color_map
>    {
>     [ 0 rgb 0 ]
>     [ .05 rgb 1 ]
>     [ 1 rgb 0 ]
>    }
>    turbulence 0.05
>   }
>
>   //we have now defined a pattern so that
>   //anything we map to 0 appears on the "dark" rings
>   //and anything we map to zero appears on the light rings
>
>   texture_map {
>    [0
>     //pattern for dark rings, a dark colour and noisy normal
>     pigment { rgb <0.9, 0.68, 0.4> }
>     finish {
>      diffuse .6
>      ambient .3
>      brilliance 1.8
>      specular .1 roughness .5 metallic .5
>     }
>     normal { granite .05 scale .4 }
>    ]
>    [1
>     //pattern for light rings, a lighter colour and striped normal
>     pigment { rgb <1, 0.8, 0.5> }
>     finish {
>      diffuse .6
>      ambient .3
>      brilliance 1.8
>      specular .1 roughness .5 metallic .5
>     }
>     normal { radial .01 rotate x*90 sine_wave frequency 200 }
>    ]
>    }
>
>   rotate <30,30,0>
>   scale .75
>   scale .3
>  }
>
> This technique isn't entirely necessary, but I find using pigment_patterns
like
> this can make it much easier to build complex textures.
>
> I hope all of this helps!
>
> -- 
> Tek
> www.evilsuperbrain.com
>
>
>


Post a reply to this message

From: Sun Tzu
Subject: Re: POVing again (~170k)
Date: 29 Feb 2004 20:36:02
Message: <40429382@news.povray.org>
Thank you!  I'll try and play around with the texture as you've shown.
Now if you can explain the 'sub surface scattering' that you referred to for
the cheese texture, I'll be set to try again.


"Tek" <tek### [at] evilsuperbraincom> wrote in message
news:4041b1ad@news.povray.org...
> >   rotate <30,30,0>
> >   scale .75
> >   scale .3
> >  }
>
> whoops, ignore that last scale .3, that's just something I was using for
my test
> you don't need it.
>
> -- 
> Tek
> www.evilsuperbrain.com
>
>
> "Tek" <tek### [at] evilsuperbraincom> wrote in message
> news:4041b15a$1@news.povray.org...
> > "Sun Tzu" <sun### [at] nospamhotmailcom> wrote in message
> > news:40418673$1@news.povray.org...
> > > I'd appreciate any specific ideas you might
> > > have for improving it.
> >
> > WARNING - this is an incredibly long reply! But it sounded like you
wanted
> some
> > tips on texturing so I've done my best:
> >
> > Okay, well one thing stands out to me straight away: that's a very
complicated
> > material, which is rather strange since we both agree it doesn't look so
good.
> > My advice would always be keep the material very simple until you have
nearly
> > the effect you like.
> >
> > So, following that I'd suggest this much simpler version might be a good
> > starting point:
> >  texture {
> >   pigment {
> >    wood
> >    ramp_wave
> >    color_map
> >    {
> >     [0 rgb <0.6, 0.35, 0.2> ]
> >     [1 rgb <0.9, 0.65, 0.3> ]
> >    }
> >    turbulence 0.05
> >   }
> >   finish {
> >    diffuse .7
> >    ambient .3
> >   }
> >   rotate <30,30,0>
> >   scale 0.75
> >  }
> >
> > Now, from this we can start looking at some more complex effects,
firstly we
> can
> > change the colour map so it returns smoothly to it's starting point:
> >    color_map {
> >     [ 0.0 rgb <0.6, 0.35, 0.2> ]
> >     [ 0.8 rgb <0.9, 0.65, 0.3> ]
> >     [ 1.0 rgb <0.6, 0.35, 0.2> ]
> >    }
> > Note that the colour at 1 is now the same as the colour at 0. This will
remove
> > the hard transition that occured before.
> >
> > Now, before we add anything else I think we should decide whether the
colours
> > look right. Personally I think they look far too dark for a chopping
board, so
> > I'd try something a bit lighter and yellower:
> >     [ 0.0 rgb <0.9, 0.68, 0.4> ]
> >     [ 0.8 rgb <1, 0.8, 0.5> ]
> >     [ 1.0 rgb <0.9, 0.68, 0.4> ]
> >
> > That's still not perfect so I recommend you spend a bit longer at this
stage
> > until you get some colours you like.
> >
> > Now, let's alter the pattern of the stripes. That 0.8 value in the
colour map
> > can be changed to alter the way that the colours vary across the
surface, also
> > the ramp_wave can be changed for one of pov's other types to create
different
> > effects. Here's one example that I like but there's many other
possibilities:
> >
> >  pigment {
> >    wood
> >    poly_wave 2
> >    color_map
> >    {
> >     [ 0 rgb <0.9, 0.68, 0.4> ]
> >     [ .05 rgb <1, 0.8, 0.5> ]
> >     [ 1 rgb <0.9, 0.68, 0.4> ]
> >    }
> >    turbulence 0.05
> >  }
> >
> > Now, lets look at the finish. The wood you had originally had a lot of
> > reflection and phong highlights, this suggests a varnished wood, but of
course
> > chopping boards aren't varnished. So let's instead try to get a smooth
but not
> > polished sheen to it. No reflections, since chopping boards aren't
really
> > reflective, a soft and subtle highlight, and we'll tweak the brightness
of the
> > material.
> >
> >   finish {
> >    diffuse .5
> >    ambient .3
> >    brilliance 1.8
> >    specular .2 roughness .5 metallic 1
> >   }
> >
> > There's 2 important things to notice here: the brilliance value alters
the way
> > that the diffuse lighting looks, larger values give a more gradual
falloff.
> And
> > the metallic specular highlight with a high roughness value behaves sort
of
> like
> > a half-specular/half-diffuse light. It's a trick I used to create
metallic
> > paint, but in this situation it's trying to fake the sheen that
unvarnished
> wood
> > has.
> >
> > Now, there's one final thing I'd like to do to this material, it's
looking a
> bit
> > flat so let's give it a normal map:
> >
> >   normal {
> >    wood
> >    poly_wave 2
> >    turbulence 0.05
> >    normal_map
> >    {
> >     [ 0 granite .05 scale .4 ]
> >     [ .05 radial .01 rotate x*90 sine_wave frequency 200 ]
> >     [ 1 granite .05 scale .4 ]
> >    }
> >   }
> >
> > What I've done here is use the exact same basic pattern as the pigment,
but
> > instead of blending 2 different colours I'm blending 2 normal patterns.
> There's
> > a radial one rotated to give perpendicular stripes across the rings in
the
> wood,
> > and a granite texture to add noise to the darker patches of wood.
> >
> > Finally, we can tidy this up so that we don't have to have 2 copies of
this
> > pattern, like so:
> >
> >  texture {
> >   pigment_pattern {
> >    //first let's take care of the wood pattern.
> >    wood
> >    poly_wave 2
> >    color_map
> >    {
> >     [ 0 rgb 0 ]
> >     [ .05 rgb 1 ]
> >     [ 1 rgb 0 ]
> >    }
> >    turbulence 0.05
> >   }
> >
> >   //we have now defined a pattern so that
> >   //anything we map to 0 appears on the "dark" rings
> >   //and anything we map to zero appears on the light rings
> >
> >   texture_map {
> >    [0
> >     //pattern for dark rings, a dark colour and noisy normal
> >     pigment { rgb <0.9, 0.68, 0.4> }
> >     finish {
> >      diffuse .6
> >      ambient .3
> >      brilliance 1.8
> >      specular .1 roughness .5 metallic .5
> >     }
> >     normal { granite .05 scale .4 }
> >    ]
> >    [1
> >     //pattern for light rings, a lighter colour and striped normal
> >     pigment { rgb <1, 0.8, 0.5> }
> >     finish {
> >      diffuse .6
> >      ambient .3
> >      brilliance 1.8
> >      specular .1 roughness .5 metallic .5
> >     }
> >     normal { radial .01 rotate x*90 sine_wave frequency 200 }
> >    ]
> >    }
> >
> >   rotate <30,30,0>
> >   scale .75
> >   scale .3
> >  }
> >
> > This technique isn't entirely necessary, but I find using
pigment_patterns
> like
> > this can make it much easier to build complex textures.
> >
> > I hope all of this helps!
> >
> > -- 
> > Tek
> > www.evilsuperbrain.com
> >
> >
> >
>
>


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From: Sun Tzu
Subject: Re: POVing again (~170k)
Date: 29 Feb 2004 20:40:50
Message: <404294a2@news.povray.org>
Thank you!  Between you and Tek, I'll have enough things to figure out, to
keep me busy for awhile.   If only I didn't have to work and could play at
this stuff all the time.   Of course then I couldn't afford a computer,
hehe.


"Dan P" <dan### [at] yahoocom> wrote in message
news:40418bde@news.povray.org...
> "Sun Tzu" <sun### [at] nospamhotmailcom> wrote in message
> news:40418355@news.povray.org...
> > Thanks for the suggestions.  I'm not that experienced with POV though so
> I'm
> > not sure exactly how to implement your ideas.   The materials always
seem
> to
> > be one of my biggest problems.  I obviously need some tutoring in making
> > good materials.  How would I "average in a wrinkles pigment" on the
label.
>
> Averaging pigments together is a very powerful too. To average pigments
> together, use a "pigment_map" and a map type of "average". The following
> code creates a plasma effect by averaging three pigments together. Note
that
> the "weight" of pigment for each is "1". Because there are three averaged
> together, in order to get a value of "1.0" for full color, I have to use
"3"
> for the color value (3 times the amount of 1):
>
> plane
> {
>  z, 1
>
>  pigment
>  {
>   average
>
>   pigment_map
>   {
>    [ 1  wrinkles
>
>     color_map
>     {
>      [0 rgb <0, 0, 0> ]
>      [1 rgb <3, 0, 0> ]
>     }
>    ]
>
>
>    [ 1 wrinkles
>
>     color_map
>     {
>      [0 rgb <0, 0, 0> ]
>      [1 rgb <0, 3, 0> ]
>     }
>
>     translate 0.5
>     ]
>
>    [ 1 wrinkles
>
>     color_map
>     {
>      [0 rgb <0, 0, 0> ]
>      [1 rgb <0, 0, 3> ]
>     }
>
>     translate -0.5
>     ]
>   }
>  }
>
>  finish { ambient 1 }
> }
>
> > Even more mysterious to me is the "subsurface scattering" that both you
> and
> > Tek suggest.  Here is the outside surface of the cheese, the 'sliced'
> > surfaces and bubbles are the same but without the normal.  How would I
put
> > in subsurface scattering?
>
> I'd like to know too -- I haven't advanced to the point of being able to
do
> that. Tek knows more about that stuff than I. There is this really great
> animation out there that shows subsurface scattering -- it was this marble
> pyramid people were talking about a while back that was really something.
> The code to that pyramid would really advance our understanding.
Christopher
> Huff is also amazingly knowledgeable about densities and the like.
>
>


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