Here is my current project and two questions:

* Why can't I get blobs blobby? This is my first attempt with blobs, and as you
can see there is a sharp edge where the bump making spheres intersects the ball
sphere.

* How do I prevent the image maps from appearing at the reverse side? I've
tried gradient texture maps, but was told that texture maps couldn't be used in
layered textures. (or something)

sig.

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Attachments:
Download 'baseball.jpg' (24 KB)

Preview of image 'baseball.jpg'

"Sigmund Kyrre Aas" <as### [at] studntnuno> wrote in message
news:38AFF53B.4A483B33@stud.ntnu.no...
>
> Here is my current project and two questions:
>
> * Why can't I get blobs blobby? This is my first attempt
> with blobs, and as you can see there is a sharp edge
> where the bump making spheres intersects the ball
> sphere.
>
> * How do I prevent the image maps from appearing at
> the reverse side? I've tried gradient texture maps, but
> was told that texture maps couldn't be used in layered
> textures. (or something)

While I can't answer your first question, here's a link to a tutorial
dealing with your second:

http://members.xoom.com/yang4yang/pov/imap1.html

Good luck.

Eric
--------------------
http://www.datasync.com/~ericfree
--------------------
"The whole problem with the world is that fools and fanatics are always so
certain of themselves, but wiser people so full of doubts."
--Bertrand Russel

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Are you enclosing the ball sphere and the bump spheres in a single blob{}
statement? If you have them in separate blob{} statements, they won't blob
together when they intersect.

--
Paul Vanukoff
van### [at] primenetcom


Sigmund Kyrre Aas wrote in message <38AFF53B.4A483B33@stud.ntnu.no>...
>Here is my current project and two questions:
>
>* Why can't I get blobs blobby? This is my first attempt with blobs, and as
you
>can see there is a sharp edge where the bump making spheres intersects the
ball
>sphere.

Post a reply to this message

Paul Vanukoff wrote:
> 
> Are you enclosing the ball sphere and the bump spheres in a single blob{}
> statement? If you have them in separate blob{} statements, they won't blob

Yes. Here it is: 

blob {
    threshold .8
    sphere {<0, 0, 0>, R*3.05, 1.004 }
    $a=0;
    $AntKuler=500;
    $d=1/AntKuler;
    #while (a<1)
        $Her=eval_3d_spline("Seam",a);
        $Der=eval_3d_spline("Seam",a+d);
        $Retn=vnormalize( Der-Her);
        $Tvers=vnormalize(vcross(Retn,Her) );
        $Norm=vnormalize(Her);
        sphere { 0, .25 ,1.2 scale <.33,1,1>  // bulk utover
            matrix <Norm.x,Norm.y,Norm.z,
                    Retn.x,Retn.y,Retn.z,
                    Tvers.x,Tvers.y,Tvers.z,
                    0   ,0   ,0    >
            translate Her*.99
        }

            matrix <Norm.x,Norm.y,Norm.z,
                    Retn.x,Retn.y,Retn.z,
                    Tvers.x*.2,Tvers.y*.2,Tvers.z*.2,
                    0   ,0   ,0    >
            translate Her*1.02
        }

            matrix <Norm.x,Norm.y,Norm.z,
                    Retn.x,Retn.y,Retn.z,
                    Tvers.x,Tvers.y,Tvers.z,
                    0   ,0   ,0    >
            translate Her*1.04
        }
        $a=a+d;
    #end
    texture{pigment {Green}}
    texture{pigment {Svart}}
    texture {pigment {Batter}}
    texture {pigment {Logo}}
    texture {pigment {Major}}
    finish {specular .1 roughness .05}
    normal { granite 0.5  scale .01 }
}

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Eric Freeman wrote:
> While I can't answer your first question, here's a link to a tutorial
> dealing with your second:
> 
> http://members.xoom.com/yang4yang/pov/imap1.html

Nice tutorial, but it didn't solve my problem. 

Now I've tried material maps too, but I get the same message when I try to use
them in layers: "Cannot layer a patterned texture over another"

sig.

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'threshold .8' might be a little tight, perhaps lower that.  'blob' hardly ever
loses it's creases between components completely though.

Bob

"Sigmund Kyrre Aas" <as### [at] studntnuno> wrote in message
news:38B01B76.9AB0BDE7@stud.ntnu.no...
| Paul Vanukoff wrote:
| >
| > Are you enclosing the ball sphere and the bump spheres in a single blob{}
| > statement? If you have them in separate blob{} statements, they won't blob
|
| Yes. Here it is:
|
| blob {
|     threshold .8
|     sphere {<0, 0, 0>, R*3.05, 1.004 }
|     $a=0;
|     $AntKuler=500;
|     $d=1/AntKuler;
|     #while (a<1)
|         $Her=eval_3d_spline("Seam",a);
|         $Der=eval_3d_spline("Seam",a+d);
|         $Retn=vnormalize( Der-Her);
|         $Tvers=vnormalize(vcross(Retn,Her) );
|         $Norm=vnormalize(Her);
|         sphere { 0, .25 ,1.2 scale <.33,1,1>  // bulk utover
|             matrix <Norm.x,Norm.y,Norm.z,
|                     Retn.x,Retn.y,Retn.z,
|                     Tvers.x,Tvers.y,Tvers.z,
|                     0   ,0   ,0    >
|             translate Her*.99
|         }

|             matrix <Norm.x,Norm.y,Norm.z,
|                     Retn.x,Retn.y,Retn.z,
|                     Tvers.x*.2,Tvers.y*.2,Tvers.z*.2,
|                     0   ,0   ,0    >
|             translate Her*1.02
|         }

|             matrix <Norm.x,Norm.y,Norm.z,
|                     Retn.x,Retn.y,Retn.z,
|                     Tvers.x,Tvers.y,Tvers.z,
|                     0   ,0   ,0    >
|             translate Her*1.04
|         }
|         $a=a+d;
|     #end
|     texture{pigment {Green}}
|     texture{pigment {Svart}}
|     texture {pigment {Batter}}
|     texture {pigment {Logo}}
|     texture {pigment {Major}}
|     finish {specular .1 roughness .05}
|     normal { granite 0.5  scale .01 }
| }

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Sigmund Kyrre Aas wrote:

> Here is my current project and two questions:

I can't answer either of your questions, but I am mightly impressed with the ball.

Could you post the texture you used for the leather? Very nice!

Simon

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> * Why can't I get blobs blobby? This is my first attempt with blobs, and as you
> can see there is a sharp edge where the bump making spheres intersects the ball
> sphere.

First, decrease your threshold to .1.  As for the intersections, you should make
multiple copies of the objects you wish to blob. Make the components increase in
diameter, and decrease the component power.  This "feathers" the edges, resulting
in a much smoother edge.


> * How do I prevent the image maps from appearing at the reverse side? I've
> tried gradient texture maps, but was told that texture maps couldn't be used in
> layered textures. (or something)

This actually works just fine. The texture on my sports car is entirely dependent
on this working just fine. my suggestion is to experiment.


--
H.E. Day

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"Sigmund Kyrre Aas" <as### [at] studntnuno> wrote in message
news:38B02C3E.D0BC1000@stud.ntnu.no...
>
> Nice tutorial, but it didn't solve my problem.
>
> Now I've tried material maps too, but I get the
> same message when I try to use them in layers:
> "Cannot layer a patterned texture over another"
>
> sig.

Here's a code snippet from a drinking glass I made using a different
technique.  Basically you create a second object (slightly larger than the
original and hollow), apply the logo image map to it, and chop off the back
half by differencing it with a box.

// make a drinking glass from the difference
// of two cylinders
#declare GlassMain = difference {
  cylinder {
    <0,0,0>,
    <0,Hite,0>
    Rad
  }
  cylinder {
    <0,0.1,0>,
    <0,Hite+1,0>
    Rad*0.9
  }
  material {GlassMat}
}

// make another hollow cylinder with a slightly larger
// radius than the drinking glass and chop off the back
// of it by differencing it with a box
#declare Logo = difference {
  cylinder { // main cylinder
    <0, -0.7, 0>,
    <0,  0.7, 0>
    Rad+0.00002
  }
  cylinder { // cut-out
    <0,-0.71,0>,
    <0,0.71,0>
    Rad+0.00001
  }
  box { // chop off the back half of the cylinder
    <-Rad-0.1,-0.71,0>,
    <Rad+0.1,0.71,Rad+0.1>
  }
  texture {
    pigment {
      image_map {
        gif "logo_image.gif"
        transmit 209, 1.0 // make the background of the image transparent
        once
        map_type 0
        interpolate 2
      }
    }
    // scale the logo to fit
    translate <-0.5,-0.5,0>
    scale <224/167,1,1>
    scale 1.4
  }
  // position the logo cylinder on the drinking glass
  translate <0,3.75,0>
  rotate y*11
}

#declare DrinkingGlass = union {
  object {GlassMain}
  object {Logo}
}

Eric
--------------------
http://www.datasync.com/~ericfree
--------------------
"The whole problem with the world is that fools and fanatics are always so
certain of themselves, but wiser people so full of doubts."
--Bertrand Russel

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Simon de Vet wrote:
> 
> I can't answer either of your questions, but I am mightly impressed with the ball.
> 
> Could you post the texture you used for the leather? Very nice!


Thanks! It's quite simple actually. I got it pretty much at first attempt:

$Green=
pigment { bozo
    colour_map {
        [0 rgb <255,249,227>/255]
        [0.5 rgb <233,255,227>/255 ]
        [0.8 rgb <219,205,150>/255 ]
        [1 rgb <255,249,227>/255]
    }
}
$Svart=
pigment { ripples
    colour_map {
        [0 rgb 1]
        [0.8 rgbf <131,105,55,90>/255 ]
        [1 rgbf 1]
    }
}

(see previous posting for the rest)

sig.

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