Do you mean intersecting the torus/tori with two planes at the appropriate
angle to each other, with textures/colors/whatever undefined?
-MW


Ron Parker <ron### [at] povrayorg> wrote in message
news:slr### [at] fwicom...
> On Fri, 19 Jan 2001 14:19:46 -0500, Mark M. Wilson wrote:


>
> Intersect it with two planes and/or a prism.
>
> --
> Ron Parker   http://www2.fwi.com/~parkerr/traces.html
> My opinions.  Mine.  Not anyone else's.

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Mark M. Wilson <mrm### [at] worldnetattnet> wrote:
: Do you mean intersecting the torus/tori with two planes at the appropriate
: angle to each other, with textures/colors/whatever undefined?

  I think that what you want is to clip the torus with the planes instead
of calculating the intersection.
  Use clipped_by.

-- 
char*i="b[7FK@`3NB6>B:b3O6>:B:b3O6><`3:;8:6f733:>::b?7B>:>^B>C73;S1";
main(_,c,m){for(m=32;c=*i++-49;c&m?puts(""):m)for(_=(
c/4)&7;putchar(m),_--?m:(_=(1<<(c&3))-1,(m^=3)&3););}    /*- Warp -*/

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Your question's been answered, but I would point out to you that if you want to
do an arc greater than 180 degrees, you must intersect or difference with a
merge of two planes, because a plane obviously can't be more than 180 degrees.

--
David Fontaine  <dav### [at] faricynet>  ICQ 55354965
My raytracing gallery:  http://davidf.faricy.net/

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I actually have not had any luck with /any/ of the techniques submitted
here.  (Everyone's responses are appreciated, nonetheless; this is not the
voice of ingratitude speaking )
The problem seems to come when I try and union or merge the two partial arcs
so that they form the characteristically Gothic ogival arch.  When I made
the actual archway, intersecting two inverse cylinders (or subtracting two
intersected cylinders from a 'box' ) was no problem.
I just can't get the tori to behave the same, because there is open space in
the middle.
I was at a concert in a Gothic-style chapel last night, and was getting
ideas about possibly trying to stack many prism objects, rotating them
around the edge of the arch...
I'm also researching options in a modeller, such as Blender, but have yet to
get up to speed on its UI.
Maybe I'm just too ambitious for a new user...

Thanks,
Mark

David Fontaine <dav### [at] faricynet> wrote in message
news:3A68DD89.16525697@faricy.net...
> Your question's been answered, but I would point out to you that if you
want to
> do an arc greater than 180 degrees, you must intersect or difference with
a
> merge of two planes, because a plane obviously can't be more than 180
degrees.
>
> --
> David Fontaine  <dav### [at] faricynet>  ICQ 55354965
> My raytracing gallery:  http://davidf.faricy.net/
>
>

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Can you post the code that you're using?

Mark M. Wilson wrote in message <3a6c9cdf$1@news.povray.org>...
>I actually have not had any luck with /any/ of the techniques submitted
>here.  (Everyone's responses are appreciated, nonetheless; this is not the
>voice of ingratitude speaking )
>The problem seems to come when I try and union or merge the two partial
arcs
>so that they form the characteristically Gothic ogival arch.  When I made
>the actual archway, intersecting two inverse cylinders (or subtracting two
>intersected cylinders from a 'box' ) was no problem.
>I just can't get the tori to behave the same, because there is open space
in
>the middle.

Post a reply to this message

Soon.  I take it this is an implicit offer to look at what I have so far?
Right now I've just got the trial sketch pov-file in which I've been messing
around.  I'll post it, hopefully tonight if I can get on.
Thanks,
Mark

J <no.spam> wrote in message news:3a6dc282$1@news.povray.org...
> Can you post the code that you're using?
>
> Mark M. Wilson wrote in message <3a6c9cdf$1@news.povray.org>...
> >I actually have not had any luck with /any/ of the techniques submitted
> >here.  (Everyone's responses are appreciated, nonetheless; this is not
the
> >voice of ingratitude speaking )
> >The problem seems to come when I try and union or merge the two partial
> arcs
> >so that they form the characteristically Gothic ogival arch.  When I made
> >the actual archway, intersecting two inverse cylinders (or subtracting
two
> >intersected cylinders from a 'box' ) was no problem.
> >I just can't get the tori to behave the same, because there is open space
> in
> >the middle.
>
>

Post a reply to this message

"Mark M. Wilson" wrote:

> The problem seems to come when I try and union or merge the two partial arcs
> so that they form the characteristically Gothic ogival arch.  When I made
> the actual archway, intersecting two inverse cylinders (or subtracting two
> intersected cylinders from a 'box' ) was no problem.
> I just can't get the tori to behave the same, because there is open space in
> the middle.

You mean the tori are cut by a radius so that the angle of the cut on one torus
doesn't meet up with the other torus?

I'd position the torii and then cut them then, the cutting is as simple as a
plane on the yz axis (or yx or whatever) halfway between the two.

--
David Fontaine  <dav### [at] faricynet>  ICQ 55354965
My raytracing gallery:  http://davidf.faricy.net/

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In article <3a6c9cdf$1@news.povray.org>, "Mark M. Wilson" 
<mrm### [at] worldnetattnet> wrote:

> The problem seems to come when I try and union or merge the two 
> partial arcs so that they form the characteristically Gothic ogival 
> arch. 

Maybe this is what you want instead of arc segments:
intersection {
    union {
        intersection {
            torus {1, 0.25 rotate x*90 translate -x*0.25}
            plane {-x, 0}
        }
        intersection {
            torus {1, 0.25 rotate x*90 translate x*0.25}
            plane {x, 0}
        }
    }
    plane {-y, 0}
}

-- 
Christopher James Huff
Personal: chr### [at] maccom, http://homepage.mac.com/chrishuff/
TAG: chr### [at] tagpovrayorg, http://tag.povray.org/

<><

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With my apologies to the person who would get credit for this, but for the
fact that I don't remember who sent it to me, and that they sent it directly
to my other e-mail acccount, which is at home...
Anyway, some kind soul worked out exactly what I want, and so for the
curious among you, this is what works:

(I'm leaving out the light and camera statements)

#declare gothArch = union


    difference  // right side {
     torus { 1, .08 pigment { Red }
     }
     box { <-1,-1,-2> <1,1,2>
     pigment { Red } translate -x*.6

     }
     box { <-1,-1,-1> <1,1,1> pigment { Red }
      translate <1,0,-1>
     }
 translate -x*.4        // move the edge to the z-axis
 rotate -x*90          // flip it upright
        }

  difference // left side

    torus { 1, .08 pigment { Red }
     }
     box { <-1,-1,-2> <1,1,2> pigment { Red }
    translate -x*.6
 }
    box { <-1,-1,-1> <1,1,1> pigment { Red } translate <1,0,-1>
 }
    translate -x*.4         // move the edge to the z-axis
     rotate -x*90            // flip it upright
     rotate y*180            // mirror it
  }
 }

object { gothArch }

J <no.spam> wrote in message news:3a6dc282$1@news.povray.org...
> Can you post the code that you're using?
>
> Mark M. Wilson wrote in message <3a6c9cdf$1@news.povray.org>...
> >I actually have not had any luck with /any/ of the techniques submitted
> >here.  (Everyone's responses are appreciated, nonetheless; this is not
the
> >voice of ingratitude speaking )
> >The problem seems to come when I try and union or merge the two partial
> arcs
> >so that they form the characteristically Gothic ogival arch.  When I made
> >the actual archway, intersecting two inverse cylinders (or subtracting
two
> >intersected cylinders from a 'box' ) was no problem.
> >I just can't get the tori to behave the same, because there is open space
> in
> >the middle.
>
>

Post a reply to this message

"Mark M. Wilson" wrote:
> 
> With my apologies to the person who would get credit for this, but for the
> fact that I don't remember who sent it to me, and that they sent it directly
> to my other e-mail acccount, which is at home...
> Anyway, some kind soul worked out exactly what I want, and so for the
> curious among you, this is what works:
> 
> (I'm leaving out the light and camera statements)
> 
> #declare gothArch = union
> 
>     difference  // right side {
>      torus { 1, .08 pigment { Red }
>      }
>      box { <-1,-1,-2> <1,1,2>
>      pigment { Red } translate -x*.6
> 
>      }
>      box { <-1,-1,-1> <1,1,1> pigment { Red }
>       translate <1,0,-1>
>      }
>  translate -x*.4        // move the edge to the z-axis
>  rotate -x*90          // flip it upright
>         }
> 
>   difference // left side
> 
>     torus { 1, .08 pigment { Red }
>      }
>      box { <-1,-1,-2> <1,1,2> pigment { Red }
>     translate -x*.6
>  }
>     box { <-1,-1,-1> <1,1,1> pigment { Red } translate <1,0,-1>
>  }
>     translate -x*.4         // move the edge to the z-axis
>      rotate -x*90            // flip it upright
>      rotate y*180            // mirror it
>   }
>  }
> 
> object { gothArch }

This code seems to do the same:


#declare OneSide =
intersection {
  torus {
    1, 0.08
    translate <-0.4, 0, 0>
  }
  box {
    <0, -0.08, 0>, <0.68, 0.08, 1.08>
  }
}

#declare GothArch =
union {
  object {
    OneSide
  }
  object {
    OneSide
    rotate 180*z  // Or do this: scale <-1, 1, 1>
  }
  rotate -90*x
}

object {
  GothArch
  pigment { Red }
}


-- 
Best regards,

Tor Olav

mailto:tor### [at] hotmailcom
http://www.crosswinds.net/~tok/tokrays.html

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