I need someone with expertise in making "scattered textures."  I am trying
to make skateboards wheels.
I want the texture to be like milk.  You can see in it just a little bit but
not very far.  I based this texture
from Captain Tylor's soap texture post.  While it is somewhat close it still
isn't right.  As you can see in the
picture the lettering looks okay (to me) but the top of the bearing (in the
middle of the wheel) shows through
quite brightly.  I tried lowering the filter value, but once I get the
bearing no longer showing through the
texture looks way too solid.  How can I make this texture a little more
"milky?"  I want the texture to look similar
to the ivory plastic texture in a set of dominos.  Maybe not that dense very
close.  I am using mlpov and
HDRI (with the kitchen sphere.)

(I hope this is making some sense.)

This is the lighting/radiosity setup:


#version unofficial mlpov 0.8;
global_settings {
   assumed_gamma 2.2
   max_trace_level 25
   radiosity{
      pretrace_start 0.08
      pretrace_end   0.02
      count 80
      nearest_count 5
      error_bound 1
      recursion_limit 2
      low_error_factor 0.5
      gray_threshold 0.0
      minimum_reuse 0.015
      brightness 1
      adc_bailout 0.01/2
      save_file "SkateTest.rdf"
      load_file "SkateTest.rdf"
   }
}

camera {
   location <0, 2, -11.00 >
   look_at <0,0,0>
   up <0,1,0>         // These up & right vectors are used for screen
resolution of 1280 x 1024
   right <1.25,0,0>   // These up & right vectors are used for screen
resolution of 1280 x 1024
}

light_source {<10, 100, -50> color rgb <1.12,1.10,0.85> * 0.7}   // 0.8

sphere {
   0,200
   pigment { image_map { hdr "kitchen_probe.hdr" once interpolate 2 map_type
7 } }
   finish { ambient 0.3 diffuse 0 }
   hollow
}




Here is the texture I used:

#declare OWheelMat1 =
material{
   texture {
      pigment {
         image_map {
            tga "Bullseye4A.tga"
            filter all 1
            map_type 3
            interpolate 4
            once
         }
         translate <-0.5,-0.5,0>
      }
      finish {
         ambient 0
         diffuse 1
         specular 0.75
         roughness 0.001
      }
   }
   interior {
      ior 1.33
      media {
         intervals 10
         samples 3,4
         confidence 0.9
         variance 1.0/128
         ratio 0.9
         scattering {2, rgb <80,80,80> extinction 0.3}
         method 3
      }
   }
}

Patrick Dugan

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Attachments:
Download 'Image1.jpg' (52 KB)

Preview of image 'Image1.jpg'

"Patrick Dugan" <pat### [at] usnetcomcorpcom> wrote in message
news:3e1de5ec@news.povray.org...
>
> I need someone with expertise in making "scattered textures."  I am trying
> to make skateboards wheels.
> I want the texture to be like milk.

It's all trial and error for me. I wasn't completely successful but I gave
your wheel media a try. I think the predominent thing needed was more
samples. Unless you use double digits or more there's going to be oddities
encountered, such as strange shadows and other inconsistencies. I added
density, as well as absorption, so those could be controlled instead of
leaving it up to a default. It's never easy to get the exact result you
want. So... here's what I ended up with:

camera {
  location  <0.0, 2.0, -5.0>
  look_at   <0.0, 0.0,  0.0>
  right     x*image_width/image_height
}

// create a regular point light source
light_source {
  0*x                  // light's position (translated below)
  color rgb <1,1,1>*0.8    // light's color
  translate <-5, 30, -10>
}
// Create an infinite sphere around scene and allow any pigment on it
sky_sphere {
  pigment {
    gradient y
    color_map { [0.0 color rgb <0.7,0.7,1.0>] [1.0 color blue 0.5] }
  }
}

#declare MediaTrans =
material{
   texture {
      pigment {
       rgbf 1
      }
      finish {
         ambient 0
         diffuse 1
         specular 0.75
         roughness 0.001
         reflection {
          0.025, 0.125 // it's shiney so why not reflect a little?
          }
      }
   }
   interior {
      ior 1.42 // was like water before... I just gave this a try instead
      media {
         method 3
         //intervals 10 // not really needed for type 3 media
         samples 75, 150 much more here, could be less perhaps
        // confidence 0.9
        // variance 1.0/128
        // ratio 0.9
         scattering {4, // type 4 seems to work well for solid things, imho
                             rgb 2.5 // being 80 might have caused trouble
(?)
                             extinction 0.75 // if this is low media seems
to lose solidness
          }
         density {
          rgb 25 // increase solidness (?)
         }
         absorption 0.25
      }
   }
}

#declare Metal =
material {
 texture {
  pigment {
   rgb 0.5
  }
  finish {
   ambient 0.5 // wanted it visible while checking media
   diffuse 0.5
   reflection {
    0.25, 0.5
   }
  }
 }
}

union {
torus {
 1, 0.5
 material {
  MediaTrans
 }
hollow
}
torus {
 0.3, 0.3
 material {
  Metal
 }
}
 rotate <90,45,0>
}

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Thanks!  Using an image_map instead of a straight pigment seems to cause me
the most trouble.  The image map version seems to be more difficult to get
"murky."  I did manage to get it further by using your example, but lowering
(/) the density to 1.1.  It still isn't perfect but it looks a lot better
than it did.

"hughes, b." <omn### [at] charternet> wrote in message
news:3e1dffec@news.povray.org...
> "Patrick Dugan" <pat### [at] usnetcomcorpcom> wrote in message
> news:3e1de5ec@news.povray.org...
> >
> > I need someone with expertise in making "scattered textures."  I am
trying
> > to make skateboards wheels.
> > I want the texture to be like milk.
>
> It's all trial and error for me. I wasn't completely successful but I gave
> your wheel media a try. I think the predominent thing needed was more
> samples. Unless you use double digits or more there's going to be oddities
> encountered, such as strange shadows and other inconsistencies. I added
> density, as well as absorption, so those could be controlled instead of
> leaving it up to a default. It's never easy to get the exact result you
> want. So... here's what I ended up with:
>
> camera {
>   location  <0.0, 2.0, -5.0>
>   look_at   <0.0, 0.0,  0.0>
>   right     x*image_width/image_height
> }
>
> // create a regular point light source
> light_source {
>   0*x                  // light's position (translated below)
>   color rgb <1,1,1>*0.8    // light's color
>   translate <-5, 30, -10>
> }
> // Create an infinite sphere around scene and allow any pigment on it
> sky_sphere {
>   pigment {
>     gradient y
>     color_map { [0.0 color rgb <0.7,0.7,1.0>] [1.0 color blue 0.5] }
>   }
> }
>
> #declare MediaTrans =
> material{
>    texture {
>       pigment {
>        rgbf 1
>       }
>       finish {
>          ambient 0
>          diffuse 1
>          specular 0.75
>          roughness 0.001
>          reflection {
>           0.025, 0.125 // it's shiney so why not reflect a little?
>           }
>       }
>    }
>    interior {
>       ior 1.42 // was like water before... I just gave this a try instead
>       media {
>          method 3
>          //intervals 10 // not really needed for type 3 media
>          samples 75, 150 much more here, could be less perhaps
>         // confidence 0.9
>         // variance 1.0/128
>         // ratio 0.9
>          scattering {4, // type 4 seems to work well for solid things,
imho
>                              rgb 2.5 // being 80 might have caused trouble
> (?)
>                              extinction 0.75 // if this is low media seems
> to lose solidness
>           }
>          density {
>           rgb 25 // increase solidness (?)
>          }
>          absorption 0.25
>       }
>    }
> }
>
> #declare Metal =
> material {
>  texture {
>   pigment {
>    rgb 0.5
>   }
>   finish {
>    ambient 0.5 // wanted it visible while checking media
>    diffuse 0.5
>    reflection {
>     0.25, 0.5
>    }
>   }
>  }
> }
>
> union {
> torus {
>  1, 0.5
>  material {
>   MediaTrans
>  }
> hollow
> }
> torus {
>  0.3, 0.3
>  material {
>   Metal
>  }
> }
>  rotate <90,45,0>
> }
>
>
>

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