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From: Patrick Dugan
Subject: Turbulent Isosurface box?
Date: 23 Mar 2002 10:25:02
Message: <3c9c9e4e@news.povray.org>
How do/can you make a isosurface box that has a "rough" surface?
I have a (poor) image I made by hand of a "turbulent" box shape.  Basically
I am trying to
make boxes that look like randomly made rectangular stones that have been
placed within
a stone wall (like a fireplace) but have been chipped to be somewhat
rectangular so they
can be placed somewhat close together.


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From: John & Amy Robinson
Subject: Re: Turbulent Isosurface box?
Date: 23 Mar 2002 10:39:47
Message: <3c9ca1c3$1@news.povray.org>
"Patrick Dugan" <pat### [at] netinsnet> wrote in message
news:3c9c9e4e@news.povray.org...
> How do/can you make a isosurface box that has a "rough" surface?
> I have a (poor) image I made by hand of a "turbulent" box shape.
Basically
> I am trying to
> make boxes that look like randomly made rectangular stones that have been
> placed within
> a stone wall (like a fireplace) but have been chipped to be somewhat
> rectangular so they
> can be placed somewhat close together.
>
>
>
>
>
>
>
i used the f_rounded_box function for the walls in this image
http://www.fishinglog.com/Art/bigThe%20Keep.html


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From: Alastair Murray
Subject: Re: Turbulent Isosurface box?
Date: 23 Mar 2002 11:21:47
Message: <3c9cab9b$1@news.povray.org>
How did you get the light to shine through the dust like that?

Sources would be incredibly useful.


"John & Amy Robinson" <jro### [at] columbusrrcom> wrote in message
news:3c9ca1c3$1@news.povray.org...
>
> "Patrick Dugan" <pat### [at] netinsnet> wrote in message
> news:3c9c9e4e@news.povray.org...
> > How do/can you make a isosurface box that has a "rough" surface?
> > I have a (poor) image I made by hand of a "turbulent" box shape.
> Basically
> > I am trying to
> > make boxes that look like randomly made rectangular stones that have
been
> > placed within
> > a stone wall (like a fireplace) but have been chipped to be somewhat
> > rectangular so they
> > can be placed somewhat close together.
> >
> >
> >
> >
> >
> >
> >
> i used the f_rounded_box function for the walls in this image
> http://www.fishinglog.com/Art/bigThe%20Keep.html
>
>
>
>


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From: Christoph Hormann
Subject: Re: Turbulent Isosurface box?
Date: 23 Mar 2002 11:26:43
Message: <3C9CACC2.D0857FB6@gmx.de>
Patrick Dugan wrote:
> 
> How do/can you make a isosurface box that has a "rough" surface?

Have a look at:

http://www-public.tu-bs.de:8080/~y0013390/pov/wtunnel.html

for an example (note this is megapov syntax).

The isosurface tutorial in the Povray 3.5 docs should also give sufficient
explanation how to add 'roughness' to a shape.

Christoph

-- 
POV-Ray tutorials, IsoWood include,                 
TransSkin and more: http://www.tu-bs.de/~y0013390/  
Last updated 18 Mar. 2002 _____./\/^>_*_<^\/\.______


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From: Patrick Dugan
Subject: Re: Turbulent Isosurface box?
Date: 23 Mar 2002 11:36:58
Message: <3c9caf2a@news.povray.org>
That type would certainly be close. I am looking for a more "slate
like"/"platey" appearance but that might get me started.
Can you be more specific about the function?  I have tried the function but
simply end up with a "rounded box." I tried:

  isosurface {
     function {f_rounded_box(x,y,z, 0.25, 0.25, 0.25, 0.25) }
     pigment{Red}
     scale 0.5
  }

I'm no math whiz so I'm really not certain what the last four values should
really be.  I've tried various values but always end up with a simple
rounded box.  How do you get yours to look so randomish?  I even tried using
a noise function like this:

  isosurface {
     function {f_rounded_box(x,y,z, f_noise3d(0, y, z), f_noise3d(0, y, z),
f_noise3d(0, y, z), f_noise3d(0, y, z)) }
     pigment{Red}
     scale 0.5
  }

to no avail.  I've used Povray for many years but I am find isosurfaces to
be a bit of a black art.


"John & Amy Robinson" <jro### [at] columbusrrcom> wrote in message
news:3c9ca1c3$1@news.povray.org...
>
> "Patrick Dugan" <pat### [at] netinsnet> wrote in message
> news:3c9c9e4e@news.povray.org...
> > How do/can you make a isosurface box that has a "rough" surface?
> > I have a (poor) image I made by hand of a "turbulent" box shape.
> Basically
> > I am trying to
> > make boxes that look like randomly made rectangular stones that have
been
> > placed within
> > a stone wall (like a fireplace) but have been chipped to be somewhat
> > rectangular so they
> > can be placed somewhat close together.
> >
> >
> >
> >
> >
> >
> >
> i used the f_rounded_box function for the walls in this image
> http://www.fishinglog.com/Art/bigThe%20Keep.html
>
>
>
>


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From: Christoph Hormann
Subject: Re: Turbulent Isosurface box?
Date: 23 Mar 2002 12:05:15
Message: <3C9CB5CA.CA4992BB@gmx.de>
Patrick Dugan wrote:
> 
> That type would certainly be close. I am looking for a more "slate
> like"/"platey" appearance but that might get me started.
> Can you be more specific about the function?  I have tried the function but
> simply end up with a "rounded box." I tried:
> 
>   isosurface {
>      function {f_rounded_box(x,y,z, 0.25, 0.25, 0.25, 0.25) }
>      pigment{Red}
>      scale 0.5
>   }
> 
> I'm no math whiz so I'm really not certain what the last four values should
> really be.  I've tried various values but always end up with a simple
> rounded box.  How do you get yours to look so randomish?  I even tried using
> [...]

When looking for 'f_rounded_box' in the docs you get:

f_rounded_box(x,y,z, P0, P1, P2, P3). 
The Rounded Box is defined in a cube from <-1, -1, -1> to <1, 1, 1>. 
By changing the " Scale" parameters, the size can be adjusted, 
without affecting the Radius of curvature.
                    
P0 : Radius of curvature. Zero gives square corners, 0.1 gives corners
that match "sphere {0, 0.1}"
P1 : Scale x 
P2 : Scale y 
P3 : Scale z 

If you add/subtract a noise function to the box this should probably
achieve what you want, something like:

f_rounded_box(...) - f_noise3d(x, y, z)*0.2

(see docs section 3.6.3.6)

And you should add an appropriate container and max_gradient to the
isosurface.

Christoph

-- 
POV-Ray tutorials, IsoWood include,                 
TransSkin and more: http://www.tu-bs.de/~y0013390/  
Last updated 18 Mar. 2002 _____./\/^>_*_<^\/\.______


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From: Patrick Dugan
Subject: Re: Turbulent Isosurface box?
Date: 23 Mar 2002 12:12:41
Message: <3c9cb789@news.povray.org>
Well I have read the tutorials and attempted to create "something" that I
was pretty certain
would make a rough box shape.  Instead it is perfectly square.  For example:

 isosurface {
     function { f_rounded_box(x,y,z,0,1,1,1) - f_noise3d(x*5, y*5, z*5)*
0.25 }
     pigment{Red}
     scale 0.2
 }

I wanted a sharp cornered rounded box with some turbulence to it. I felt the
second function

f_noise3d(x*5, y*5, z*5)* 0.25

(shown in the tutorial under the sphere example) should do what I wanted.
From the tutorial it
seemed to be the most likely function, but it apparently isn't.


"Christoph Hormann" <chr### [at] gmxde> wrote in message
news:3C9CACC2.D0857FB6@gmx.de...
>
>
> Patrick Dugan wrote:
> >
> > How do/can you make a isosurface box that has a "rough" surface?
>
> Have a look at:
>
> http://www-public.tu-bs.de:8080/~y0013390/pov/wtunnel.html
>
> for an example (note this is megapov syntax).
>
> The isosurface tutorial in the Povray 3.5 docs should also give sufficient
> explanation how to add 'roughness' to a shape.
>
> Christoph
>
> --
> POV-Ray tutorials, IsoWood include,
> TransSkin and more: http://www.tu-bs.de/~y0013390/
> Last updated 18 Mar. 2002 _____./\/^>_*_<^\/\.______


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From: Christoph Hormann
Subject: Re: Turbulent Isosurface box?
Date: 23 Mar 2002 12:17:54
Message: <3C9CB8C2.E4D0FC55@gmx.de>
Patrick Dugan wrote:
> 
> [...}
>  isosurface {
>      function { f_rounded_box(x,y,z,0,1,1,1) - f_noise3d(x*5, y*5, z*5)*
> 0.25 }
>      pigment{Red}
>      scale 0.2
>  }
> 
> [...]
> From the tutorial it
> seemed to be the most likely function, but it apparently isn't.

As said in the other post you need an appropriate container object.  In
your example all surfaces are outside the (default) container, therefore
you only see the container itself.

Christoph

-- 
POV-Ray tutorials, IsoWood include,                 
TransSkin and more: http://www.tu-bs.de/~y0013390/  
Last updated 18 Mar. 2002 _____./\/^>_*_<^\/\.______


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From: Patrick Dugan
Subject: Re: Turbulent Isosurface box?
Date: 23 Mar 2002 12:18:33
Message: <3c9cb8e9@news.povray.org>
I tried:

 isosurface {
     function { f_rounded_box(x,y,z,0,1,1,1) - f_noise3d(x, y, z)* 0.25 }
     contained_by { box { -1 , 1} }
     pigment{Red}
     scale 0.2
 }

but this yields a perfectly square box.  No roughness at all.  Would the
max_gradient make or break this?



"Christoph Hormann" <chr### [at] gmxde> wrote in message
news:3C9CB5CA.CA4992BB@gmx.de...
>
>
> Patrick Dugan wrote:
> >
> > That type would certainly be close. I am looking for a more "slate
> > like"/"platey" appearance but that might get me started.
> > Can you be more specific about the function?  I have tried the function
but
> > simply end up with a "rounded box." I tried:
> >
> >   isosurface {
> >      function {f_rounded_box(x,y,z, 0.25, 0.25, 0.25, 0.25) }
> >      pigment{Red}
> >      scale 0.5
> >   }
> >
> > I'm no math whiz so I'm really not certain what the last four values
should
> > really be.  I've tried various values but always end up with a simple
> > rounded box.  How do you get yours to look so randomish?  I even tried
using
> > [...]
>
> When looking for 'f_rounded_box' in the docs you get:
>
> f_rounded_box(x,y,z, P0, P1, P2, P3).
> The Rounded Box is defined in a cube from <-1, -1, -1> to <1, 1, 1>.
> By changing the " Scale" parameters, the size can be adjusted,
> without affecting the Radius of curvature.
>
> P0 : Radius of curvature. Zero gives square corners, 0.1 gives corners
> that match "sphere {0, 0.1}"
> P1 : Scale x
> P2 : Scale y
> P3 : Scale z
>
> If you add/subtract a noise function to the box this should probably
> achieve what you want, something like:
>
> f_rounded_box(...) - f_noise3d(x, y, z)*0.2
>
> (see docs section 3.6.3.6)
>
> And you should add an appropriate container and max_gradient to the
> isosurface.
>
> Christoph
>
> --
> POV-Ray tutorials, IsoWood include,
> TransSkin and more: http://www.tu-bs.de/~y0013390/
> Last updated 18 Mar. 2002 _____./\/^>_*_<^\/\.______


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From: Bill DeWitt
Subject: Re: Turbulent Isosurface box?
Date: 23 Mar 2002 13:07:28
Message: <3c9cc460$1@news.povray.org>
"Patrick Dugan" <pat### [at] netinsnet> wrote in message
news:3c9c9e4e@news.povray.org...
> How do/can you make a isosurface box that has a "rough" surface?
> I have a (poor) image I made by hand of a "turbulent" box shape.
Basically
> I am trying to
> make boxes that look like randomly made rectangular stones that have been
> placed within
> a stone wall (like a fireplace) but have been chipped to be somewhat
> rectangular so they
> can be placed somewhat close together.

    I was just doing that too after talking to Tom about stone walls and
talking to my lovely wife about the stone wall we want in the front yard.
Here's what I've got so far, there are some odd things in it from left over
experiments but I think the basics are there. Hopefully it doesn't wrap
funny...

////////////// Camera //////////////////////
camera {                                  //
        right      <  1.333, 0.0, 0.0 >   //
        up         <  0.0, 1.0, 0.0 >    //
        direction  <  0.0, 0.0, 1.0 >     //
        location   <  3.0, 3.0, 7.0 >
        look_at    <  0.0, 0.0, 0.0 >     //
       }                                  //
////////////// end Camera //////////////////

///////////////  Light  ////////////////
light_source { < 1000.0, 1000.0, 1000.0 >
color rgb < 1.0, 1.0, 1.0 > }


#declare Rock=function{
                 pigment{
                         crackle
                         turbulence 0.25
                         color_map { [0 rgb 1] [1 rgb 0] }
                         scale < 0.5, 0.25, 0.5 >*3
                        }
                      }
#declare Wall1 = function { max((x*x*x-1),(y*y-1),(z*z-1)) }

#declare RockWall =
           isosurface {
              function {
                         Wall1(x,y,z)
                        +Rock(x,y,z).x
                        *0.5
                       }
              contained_by { box { <-8.0,-1.5,-1.5 >,
                                   < 8.0, 1.5, 1.5 > }
              accuracy 0.0001
              max_gradient 25
              pigment { rgb 1 }
              finish  { ambient 0.125 }
              translate < 0.0, 0.0, 0.0 >
            }


 object { RockWall }


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