POV-Ray : Newsgroups : povray.general : problem with differencing height_field Server Time
10 Aug 2024 07:14:55 EDT (-0400)
  problem with differencing height_field (Message 1 to 3 of 3)  
From: Paul Vanukoff
Subject: problem with differencing height_field
Date: 24 Feb 2000 13:44:49
Message: <38b57c21@news.povray.org>
Ok, I'm stumped. Anyone know why this doesn't work?


#declare o_chairseat=
difference
{
 union
 {
  torus
  {
   0.5, 0.05
   scale < 1.0, 0.5, 1.0>
   translate < 0.0, 0.4, 0.0>
  }
  disc
  {
   < 0.0, 0.425, 0.0>, < 0.0, 0.375, 0.0>, 0.5
  }
 }
 height_field
 {
  gif "simplechairhf.gif"
  smooth
  translate <-0.5, 0.0,-0.5>
  scale < 1.5,-0.1, 1.5>
  translate < 0.0, 0.426, 0.0>
 }
}

My intended effect is to rough up the upper surface of the disc/torus union
using the heightfield. The gif is nothing special, just some light noise.
What I get though is the disc/torus union with the height_field kind of
attached to the top of it. What gives? I can post images to p.b.i if
requested.



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


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From: Paul Vanukoff
Subject: Re: problem with differencing height_field
Date: 24 Feb 2000 13:58:31
Message: <38b57f57@news.povray.org>
D'oh! Never mind - I need to use a cylinder, not a disc! Oops.

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

"Paul Vanukoff" <van### [at] primenetcom> wrote in message
news:38b57c21@news.povray.org...
>
> Ok, I'm stumped. Anyone know why this doesn't work?
>
>
> #declare o_chairseat=
> difference
> {
>  union
>  {
>   torus
>   {
>    0.5, 0.05
>    scale < 1.0, 0.5, 1.0>
>    translate < 0.0, 0.4, 0.0>
>   }
>   disc
>   {
>    < 0.0, 0.425, 0.0>, < 0.0, 0.375, 0.0>, 0.5
>   }
>  }
>  height_field
>  {
>   gif "simplechairhf.gif"
>   smooth
>   translate <-0.5, 0.0,-0.5>
>   scale < 1.5,-0.1, 1.5>
>   translate < 0.0, 0.426, 0.0>
>  }
> }
>
> My intended effect is to rough up the upper surface of the disc/torus
union
> using the heightfield. The gif is nothing special, just some light noise.
> What I get though is the disc/torus union with the height_field kind of
> attached to the top of it. What gives? I can post images to p.b.i if
> requested.
>
>
>
> --
> Paul Vanukoff
> van### [at] primenetcom
>
>
>


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From: Josh English
Subject: Re: problem with differencing height_field
Date: 24 Feb 2000 14:16:13
Message: <38B5823A.95A9465@spiritone.com>
You realize that people will recommend an isosufrace to do this, don't you?
Actually, the problem is the disc.
If I take the disc out of the equation I get the heightfield "bounded" by the
torus, which I had to adjust the scale on to make some sense of it, which I
assume is because I have a different image than you do (I used one of my noise
tga files that I'm using in my IRTC entry)

Try this:
#declare o_chairseat=
difference
{
 union
 {
  torus
  {
   0.5, 0.05
   scale < 1.0, 0.5, 1.0>
   translate < 0.0, 0.4, 0.0>
  }
 }
 height_field
 {
  tga "break1.tga"
  smooth
  translate <-0.5, 0.0,-0.5>
  scale < 1.5,-0.1, 1.5>
  translate < 0.0, 0.426, 0.0>
 }
}

object {o_chairseat pigment { rgb 1 } finish { phong 1 } }

difference {
   cylinder
  {
   < 0.0, 0.425, 0.0>, < 0.0, 0.375, 0.0>, 0.5
 }
   height_field
 {
  tga "break1.tga"
  smooth
  translate <-0.5, 0.0,-0.5>
  scale < 1.5,-0.1, 1.5>
  translate < 0.0, 0.426, 0.0>
 }
  pigment { rgb <1,1,0> }  }

Josh

Paul Vanukoff wrote:

> Ok, I'm stumped. Anyone know why this doesn't work?
>
> <snip>
>
> My intended effect is to rough up the upper surface of the disc/torus union
> using the heightfield. The gif is nothing special, just some light noise.
> What I get though is the disc/torus union with the height_field kind of
> attached to the top of it. What gives? I can post images to p.b.i if
> requested.
>
> --
> Paul Vanukoff
> van### [at] primenetcom

--
Josh English
eng### [at] spiritonecom
"May your hopes, dreams, and plans not be destroyed by a few zeros."


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