Anybody have any ideas on how I could make a contour map of a height
field?  I tried trace() and dropping a sphere at a point if it had a
specific Y value, drop enough spheres and test for different heights and
you statrt to get something which is OK, but it take half-past forever.
Any other ideas? maybe a sphere sweep of some kind ??

-paul



--------------------------------------------------}
Paul Daniel Jones
The Pennslyvania State University

pdj### [at] psuedu
http://research.chem.psu.edu/glassgrp/paul

       C            The way is near, but men
     // \           seek it afar. It is in the
    N    N          easy things, but men seek it
    |    ||         in the difficult things.
    C    C          -Menicius
     \\  /
       C
--------------------------------------------------}

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Paul Jones wrote:
> 
> Anybody have any ideas on how I could make a contour map of a height
> field?  I tried trace() and dropping a sphere at a point if it had a
> specific Y value, drop enough spheres and test for different heights and
> you statrt to get something which is OK, but it take half-past forever.
> Any other ideas? maybe a sphere sweep of some kind ??
> 

What about the water-level ?
(multiple instance of the height field, each with a different water level,
and a pigment/color map which would be Clear, except around the water level,
with a vertical Gradient)

Or even just a very detailled pigment/color map with a vertical Gradient
applied to just one heightfield.
Using an orthographic camera should also help (direction -y)

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Paul Jones wrote:
> 
> Anybody have any ideas on how I could make a contour map of a height
> field?  I tried trace() and dropping a sphere at a point if it had a
> specific Y value, drop enough spheres and test for different heights and
> you statrt to get something which is OK, but it take half-past forever.
> Any other ideas? maybe a sphere sweep of some kind ??
> 
> -paul
> 

I'm not totally sure what you want to do, but as i understand it, you want
that contour lines only in povray.  

How about just using a partly transparent gradient y texture on the HF.  

If that's not a good solution, it would help a lot if you would say what
you want to use these lines for.

Christoph

-- 
Christoph Hormann <chr### [at] gmxde>
IsoWood include, radiosity tutorial, TransSkin and other 
things on: http://www.schunter.etc.tu-bs.de/~chris/

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Wouldn't a pigment (gradient y?) be enough?

-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):_;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

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Is this what you call a contour map?

http://www.cs.tut.fi/~warp/contour.jpg

  I made the image with this code:

#version Unofficial MegaPov 0.6;

camera { location <-2,15,-10> look_at 0 angle 35 }
light_source { <50,200,-100>, 1 }

isosurface
{ function { y-noise3d(x,y,z) }
  contained_by { box { <-5,0,-5><5,1,5> } }
  scale <1,4,1>
  pigment
  { gradient y color_map
    { [0 rgb 0][.1 rgb 0]
      [.1 rgb <1,.7,.2>][1 rgb <1,.7,.2>]
    }
    scale <1,.25,1>
  }
  finish { specular .25 }
}


-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):_;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

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Sorry.... 

What I want is this: To take a height field, which may or may not be
visible, and to create a series of closed loops, each loop sitting on a
specific elevation and encompasing only one "hill" of the hf. Now,
imagine that I apply a gradient y pigment to the hf, it would be
possible to get this effect, except that I want each "countour line" to
be 3-dimensional, like a pipe. 

One could also envision taking a hf and repeatedly intersecting it with
two plane, so you are left with some thin sliced in the shape of a loop.
I want those loops to be pipes. 

I hope this helps.

paul

Christoph Hormann wrote:
> 
> Paul Jones wrote:
> >
> > Anybody have any ideas on how I could make a contour map of a height
> > field?  I tried trace() and dropping a sphere at a point if it had a
> > specific Y value, drop enough spheres and test for different heights and
> > you statrt to get something which is OK, but it take half-past forever.
> > Any other ideas? maybe a sphere sweep of some kind ??
> >
> > -paul
> >
> 
> I'm not totally sure what you want to do, but as i understand it, you want
> that contour lines only in povray.
> 
> How about just using a partly transparent gradient y texture on the HF.
> 
> If that's not a good solution, it would help a lot if you would say what
> you want to use these lines for.
> 
> Christoph
> 
> --
> Christoph Hormann <chr### [at] gmxde>
> IsoWood include, radiosity tutorial, TransSkin and other
> things on: http://www.schunter.etc.tu-bs.de/~chris/

-- 



--------------------------------------------------}
Paul Daniel Jones
The Pennslyvania State University

pdj### [at] psuedu
http://research.chem.psu.edu/glassgrp/paul

       C            The way is near, but men
     // \           seek it afar. It is in the
    N    N          easy things, but men seek it
    |    ||         in the difficult things.
    C    C          -Menicius
     \\  /
       C
--------------------------------------------------}

Post a reply to this message

Warp, that is very close to what I want, but I need (well, _need_ is
subjective :-) the contours to be 3-dimensional, like tubes or sphere
sweeps. In my final image, the actual height-field will not be visible.

-paul

p.s. I like the image :-)

Warp wrote:
> 
>   Is this what you call a contour map?
> 
> http://www.cs.tut.fi/~warp/contour.jpg
> 
>   I made the image with this code:
> 
> #version Unofficial MegaPov 0.6;
> 
> camera { location <-2,15,-10> look_at 0 angle 35 }
> light_source { <50,200,-100>, 1 }
> 
> isosurface
> { function { y-noise3d(x,y,z) }
>   contained_by { box { <-5,0,-5><5,1,5> } }
>   scale <1,4,1>
>   pigment
>   { gradient y color_map
>     { [0 rgb 0][.1 rgb 0]
>       [.1 rgb <1,.7,.2>][1 rgb <1,.7,.2>]
>     }
>     scale <1,.25,1>
>   }
>   finish { specular .25 }
> }
> 
> --
> main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
> ):_;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

-- 



--------------------------------------------------}
Paul Daniel Jones
The Pennslyvania State University

pdj### [at] psuedu
http://research.chem.psu.edu/glassgrp/paul

       C            The way is near, but men
     // \           seek it afar. It is in the
    N    N          easy things, but men seek it
    |    ||         in the difficult things.
    C    C          -Menicius
     \\  /
       C
--------------------------------------------------}

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Paul Jones wrote:

>imagine that I apply a gradient y pigment to the hf, it would be
>possible to get this effect, except that I want each "countour line" to
>be 3-dimensional, like a pipe.

Try using "trace" in combination with "evaluate pigment/pattern" to put 
lots of spheres on your HF.

Ingo

-- 
Photography: http://members.home.nl/ingoogni/
Pov-Ray    : http://members.home.nl/seed7/

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Paul Jones wrote in message <3A2D1824.BCC93109@psu.edu>...
>Warp wrote:
> >   Is this what you call a contour map?
> > http://www.cs.tut.fi/~warp/contour.jpg
>
> Warp, that is very close to what I want, but I need (well, _need_ is
> subjective :-) the contours to be 3-dimensional, like tubes or sphere
> sweeps. In my final image, the actual height-field will not be
visible.


he show you proper way
just use gradient y with color map [0 black] [0.9 black][0.9 white][1
white]
and find tool in povray/links or in news/binaries which convert
ouputed image to array in pov
(I don't remeber name nor author)
than run loop which puts sphere on pixels (array entries) different than
black
or use even spline for neighbours

ABX

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Wlodzimierz ABX Skiba wrote in message <3a2d1e3d$1@news.povray.org>...
> and find tool in povray/links or in news/binaries which convert
> ouputed image to array in pov
> (I don't remeber name nor author)


but I have net :-)
http://www.coe.uncc.edu/~adwoodfi/tga.html

ABX

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