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From: Sally
Subject: Re: slightly-squared torus?
Date: 23 Apr 2004 19:44:11
Message: <4089aa4b$3@news.povray.org>
I see I have found 3 different ways of doing it, the easiest is probably
supertorus... and this brings me to a more important question.

Is there some page on the internet that has a LARGER thumbnail list of
all the shapes and their easiest way to do them?

I know PovRay has some tiny thumbnails in its menu, with a few of the
common shapes, but it would be great to have a large thumbnail list of
dozens of basic and sortof-basic shapes and ways to achieve them.

Anyone?


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From: Hughes, B 
Subject: Re: slightly-squared torus?
Date: 23 Apr 2004 21:03:45
Message: <4089bcf1$1@news.povray.org>
"Sally" <bui### [at] NOSPAMyahoocom> wrote in message
news:4089aa4b$3@news.povray.org...
>
> Is there some page on the internet that has a LARGER thumbnail list of
> all the shapes and their easiest way to do them?


Best I know of is probably going to be Friedrich Lohmueller's stuff at
http://www.f-lohmueller.de/pov_tut/pov__eng.htm
And his own macro capable of squared-off torus is at
http://www.f-lohmueller.de/pov_tut/macros/mymacr1e.htm

If he were to continue to build up that site to add all of the
already-included objects and abilities in the POV-Ray package I think it
would be the first place to visit for finding out all about POV, as well as
learning more to do with it beyond what's included.

Dr. Stefan Immel has the best POV-Ray thumbnail preview site I know of,
showing all images created from the included files.
http://caramel.oc.chemie.tu-darmstadt.de/lemmi/povray35.html

-- 
Bob H.
http://www.3digitaleyes.com


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From: Sally
Subject: Re: slightly-squared torus?
Date: 23 Apr 2004 21:15:30
Message: <4089bfb2$1@news.povray.org>
PS, I forgot to mention the key to the list is that it would show the
SIMPLEST way to achieve a shape, sometimes there are many ways. I know
there are already many lists, for example isosurface, but the ones I see
don't mention when there are simpler alternatives to one of the objects.


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From: Sally
Subject: Re: slightly-squared torus?
Date: 24 Apr 2004 01:17:57
Message: <4089f885$1@news.povray.org>
Strange, I tried an isosurface and the problem is the texture that is
showing. So I simplified the code to just a isosurface sphere and still
a problem. For example:

difference {
  anyObjectHere
   sphere { <0,0,0>, 1 }
}

works fine BUT

difference {
  anyObjectHere
    isosurface {
      function { x*x + y*y + z*z - 1 }
        max_gradient 4
        contained_by{box{-3.5,+3.5}}
      }
  }

leads to the area being "cut out" by the isosurface is very dark. Aren't
the above 2 spheres equivilant?


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From: Sally
Subject: Re: slightly-squared torus?
Date: 24 Apr 2004 01:45:38
Message: <4089ff02@news.povray.org>
Found it, something about max_trace... sorry I jumped too quickly to
asking the newsgroup this time but hopefully someone else having that
problem will read this note and know its max_trace too :)


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From: Fredrik Eriksson
Subject: Re: slightly-squared torus?
Date: 24 Apr 2004 13:39:26
Message: <opr6y1zzoqzjc5hb@news.povray.org>
On Fri, 23 Apr 2004 14:52:21 +0300, Severi Salminen 
<sev### [at] NOT_THISsibafi> wrote:
> I don't think that is what Sally wanted. Your macro alters the 
> minor_radius, Sally wanted to alter the shape of major_radius.

Yes; it seems I misunderstood the question.

Allow me to retry:

Is this
http://hem.bredband.net/b230591/povray/squared_torus2.jpg
anything like what you (Sally) are looking for?

These are super-shapes with varying values of n1, n2 & n3 for the first 
shape.


---
FE


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From: Alain
Subject: Re: slightly-squared torus?
Date: 24 Apr 2004 17:46:02
Message: <408ae01a@news.povray.org>
Fredrik Eriksson nous apporta ses lumieres ainsi en ce 2004/04/24 
13:39... :

> On Fri, 23 Apr 2004 14:52:21 +0300, Severi Salminen 
> <sev### [at] NOT_THISsibafi> wrote:
>
>> I don't think that is what Sally wanted. Your macro alters the 
>> minor_radius, Sally wanted to alter the shape of major_radius.
>
>
> Yes; it seems I misunderstood the question.
>
> Allow me to retry:
>
> Is this
> http://hem.bredband.net/b230591/povray/squared_torus2.jpg
> anything like what you (Sally) are looking for?
>
> These are super-shapes with varying values of n1, n2 & n3 for the 
> first shape.
>
>
> ---
> FE

I think that's exactly the wanted shape

Alain


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From: Rafal 'Raf256' Maj
Subject: Re: slightly-squared torus?
Date: 24 Apr 2004 19:44:07
Message: <Xns94D6118BF831Fraf256com@203.29.75.35>
bui### [at] NOSPAMyahoocom news:4089ff02@news.povray.org

> Found it, something about max_trace... sorry I jumped too quickly to
> asking the newsgroup this time but hopefully someone else having that
> problem will read this note and know its max_trace too :)

isosurface {
  function { FUNCTION_ITEMS }
[...]
  [max_trace INTEGER] | [all_intersections]
}


max_trace Isosurfaces can be used in CSG shapes since they are solid finite 
objects - if not finite by themselves, they are through the cross section 
with the container. 
By default POV-Ray searches only for the first surface which the ray 
intersects. But when using an isosurface in CSG operations, the other 
surfaces must also be found. Therefore, the keyword max_trace must be added 
to the isosurface statement. It must be followed by an integer value. To 
check for all surfaces, use the keyword all_intersections instead. 
With all_intersections POV-Ray keeps looking until all surfaces are found. 
With a max_trace it only checks until that number is reached.


-- 
http://www.raf256.com/3d/
Rafal Maj 'Raf256', home page - http://www.raf256.com/me/
Computer Graphics


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From: cubicon
Subject: Re: slightly-squared torus?
Date: 1 May 2004 15:25:00
Message: <web.4093f922ee9f5118ac0dff0b0@news.povray.org>
You could use csg also; a union of 2 rings (difference between 2 cylinders)
and 4 torus, but that 6 objects, not very efficient.


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From: cubicon
Subject: Re: slightly-squared torus?
Date: 1 May 2004 15:55:00
Message: <web.40940045ee9f5118ac0dff0b0@news.povray.org>
Sorry, I missunderstood.
The code:
#local minorR = 1;
#local majorR = 3;
#local strW = 3;
// total width = strW + majorR*2 + minorR*2
// total height = minorR*2

#local SecObj =
difference{

#local LR = majorR;
#local sr = minorR;
#local Y0 = 0;
torus{LR, sr translate y*Y0 }

plane  { <1,0,0>, 0 }
plane  { <0,0,1>, 0 }
}

#local DesiredObj = union{
#local Count = 3;
#local I = 0;
#while ( I <= Count )

   object{ SecObj translate<strW/2,0,strW/2> rotate y*90*I }
   #local cylR = minorR;
   #local cylW = strW;
   cylinder{<-cylW/2, 0, 0>  <cylW/2, 0, 0> cylR
translate<0,0,strW/2+majorR> rotate y*90*I }



#local I = I + 1;
#end
}

object{ DesiredObj }

produces this shape: http://www.geocities.com/fcmodelview/sqrtorus.jpg


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