POV-Ray : Newsgroups : povray.binaries.images : superellipsoidtest - failed? Server Time
17 Aug 2024 14:18:31 EDT (-0400)
  superellipsoidtest - failed? (Message 1 to 10 of 10)  
From: marabou
Subject: superellipsoidtest - failed?
Date: 4 Oct 2001 15:30:52
Message: <3bbcb8e9@news.povray.org>
hello!

i tested a little bit superellipsoids. with the following code i got a 
funny pattern on it. does anybody know why? 

-------------------------
superellipsoid{
        <0.25,0.0001>
        pigment{Gray}
        scale 0.25
        rotate y*-20
        translate <0,0.5,0.5>
}

-------------------------

thanks.


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From: marabou
Subject: Re: superellipsoidtest - failed? =part II=
Date: 4 Oct 2001 15:37:49
Message: <3bbcba8d@news.povray.org>
marabou wrote:

> 
> hello!
> 
> i tested a little bit superellipsoids. with the following code i got a
> funny pattern on it. does anybody know why?
> 
> -------------------------
> superellipsoid{
>         <0.25,0.0001>
>         pigment{Gray}
>         scale 0.25
>         rotate y*-20
>         translate <0,0.5,0.5>
> }
> 
> -------------------------

i forgot to say: if i take the following parameters the pattern is not 
there:

 superellipsoid{
        <0.25,0.001>


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From: Slime
Subject: Re: superellipsoidtest - failed? =part II=
Date: 5 Oct 2001 00:10:45
Message: <3bbd32c5$1@news.povray.org>
It seems to me that POV-Ray 3.5 doesn't like numbers that small. That
confused me since I'm used to using numbers such as .00000001 to avoid
coincident surfaces. But I'm curious as to why it's so sensitive now. It
seems to round real small numbers down to zero or something.

--
- Slime
[ http://www.slimeland.com/ ]
[ http://www.slimeland.com/images/ ]
"marabou" <not### [at] availableyet> wrote in message
news:3bbcba8d@news.povray.org...
> marabou wrote:
>
> >
> > hello!
> >
> > i tested a little bit superellipsoids. with the following code i got a
> > funny pattern on it. does anybody know why?
> >
> > -------------------------
> > superellipsoid{
> >         <0.25,0.0001>
> >         pigment{Gray}
> >         scale 0.25
> >         rotate y*-20
> >         translate <0,0.5,0.5>
> > }
> >
> > -------------------------
>
> i forgot to say: if i take the following parameters the pattern is not
> there:
>
>  superellipsoid{
>         <0.25,0.001>


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From: Nekar Xenos
Subject: Re: superellipsoidtest - failed?
Date: 5 Oct 2001 03:31:34
Message: <3bbd61d6@news.povray.org>
It looks like you could almost make a Union Jack with that =)

- Nekar
"marabou" <not### [at] availableyet> wrote in message news:3bbcb8e9@news.povray.org...
>
> hello!
>
> i tested a little bit superellipsoids. with the following code i got a
> funny pattern on it. does anybody know why?
>
> -------------------------
> superellipsoid{
>         <0.25,0.0001>
>         pigment{Gray}
>         scale 0.25
>         rotate y*-20
>         translate <0,0.5,0.5>
> }
>
> -------------------------
>
> thanks.


Post a reply to this message

From: marabou
Subject: Re: superellipsoidtest - failed? =part II=
Date: 5 Oct 2001 03:42:02
Message: <3bbd644a@news.povray.org>
Slime wrote:

> It seems to me that POV-Ray 3.5 doesn't like numbers that small. That
> confused me since I'm used to using numbers such as .00000001 to avoid
> coincident surfaces. But I'm curious as to why it's so sensitive now. It
> seems to round real small numbers down to zero or something.

nice to know that this (problem?) exists in 3.5, too. i used 3.1g.


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From: Jérôme Grimbert
Subject: Re: superellipsoidtest - failed?
Date: 5 Oct 2001 03:47:35
Message: <3BBD65A3.B40EAFBA@atosorigin.com>
marabou wrote:
> 
> hello!
> 
> i tested a little bit superellipsoids. with the following code i got a
> funny pattern on it. does anybody know why?
> 
> -------------------------
> superellipsoid{
>         <0.25,0.0001>

Know problem of 3.1 (at least the union jack illumination)

I made a proposal to solve that problem, a long time ago.

If you can read french, 
read http://jgrimbert.free.fr/pov/correct/superellipsoid.html
(otherwise, you can still look at the pictures)


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From: marabou
Subject: Re: superellipsoidtest - failed?
Date: 5 Oct 2001 04:03:17
Message: <3bbd6945@news.povray.org>


> 
> Know problem of 3.1 (at least the union jack illumination)
> I made a proposal to solve that problem, a long time ago.
> 
> If you can read french,
> read http://jgrimbert.free.fr/pov/correct/superellipsoid.html
> (otherwise, you can still look at the pictures)

i can not read french, but the hint is great. 
about the mesh site is there an english version? or an equivalent site?


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From: Christoph Hormann
Subject: Re: superellipsoidtest - failed?
Date: 5 Oct 2001 07:53:26
Message: <3BBDA00D.970B0FF1@gmx.de>
marabou wrote:
> 
> i can not read french, but the hint is great.
> about the mesh site is there an english version? or an equivalent site?

Try 'bable fish' at Altavista: http://www.altavista.com/

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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From: Christoph Hormann
Subject: Re: superellipsoidtest - failed? =part II=
Date: 5 Oct 2001 08:17:43
Message: <3BBDA5BB.89BC5922@gmx.de>
marabou wrote:
> 
> nice to know that this (problem?) exists in 3.5, too. i used 3.1g.

Oh, just to mention, it does *not* occur in Povray 3.5 (although there are
still artefacts with these parameters).

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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From: Slime
Subject: Re: superellipsoidtest - failed? =part II=
Date: 5 Oct 2001 12:04:56
Message: <3bbdda28$1@news.povray.org>
Heh, funny, because I never noticed any problem with tiny numbers in version
3.1. Ah, well.

--
- Slime
[ http://www.slimeland.com/ ]
[ http://www.slimeland.com/images/ ]
"Christoph Hormann" <chr### [at] gmxde> wrote in message
news:3BBDA5BB.89BC5922@gmx.de...
>
>
> marabou wrote:
> >
> > nice to know that this (problem?) exists in 3.5, too. i used 3.1g.
>
> Oh, just to mention, it does *not* occur in Povray 3.5 (although there are
> still artefacts with these parameters).
>
> 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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