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From: Tor Olav Kristensen
Subject: Almost Sphere Spirals (109 KB)
Date: 24 Jan 2002 22:34:05
Message: <3C508AF7.260EBD52@hotmail.com>
I'm not sure if this image is finished
or not now.

What do you think ?

Should I change something ?

I should probably mention that I had
to "hand correct" the finished image
somewhat at the sphere's "south pole".

(Because there seems to be some
calculations that are not calculated
correctly by POV-Ray. Increasing
max_gradient or accuracy did not help
at all.)

I have also used Micrografx Picture
Publisher to increase the contrast a
little.


Tor Olav


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Attachments:
Download 'riemann16_.jpg' (109 KB)

Preview of image 'riemann16_.jpg'
riemann16_.jpg


 

From: Bill DeWitt
Subject: Re: Almost Sphere Spirals (109 KB)
Date: 24 Jan 2002 23:22:38
Message: <3c50973e@news.povray.org>
All it needs is a guy looking up at it. Make him so small that he can be
mistaken for a spot, then you notice the shadow and the scale suddenly
shifts...


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From: Fernando González del Cueto
Subject: Re: Almost Sphere Spirals (109 KB)
Date: 24 Jan 2002 23:49:52
Message: <3c509da0@news.povray.org>
Fantastic, I like the image just as it is.

Congratulations,

Fernando.


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From: Slime
Subject: Re: Almost Sphere Spirals (109 KB)
Date: 25 Jan 2002 00:01:28
Message: <3c50a058@news.povray.org>
> (Because there seems to be some
> calculations that are not calculated
> correctly by POV-Ray. Increasing
> max_gradient or accuracy did not help
> at all.)

If you defined the spiral correctly, that's because the spiral never ends,
the detail increases towards the poles infinitely. That is, if I understood
the description of the shape that I read a while ago correctly.

- Slime
[ http://www.slimeland.com/ ]
[ http://www.slimeland.com/images/ ]


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From: Anton Sherwood
Subject: Re: Almost Sphere Spirals (109 KB)
Date: 25 Jan 2002 05:59:10
Message: <3C50F653.C48210C0@pobox.com>
Tor Olav:
> > (Because there seems to be some
> > calculations that are not calculated
> > correctly by POV-Ray. Increasing
> > max_gradient or accuracy did not help
> > at all.)

Slime:
> If you defined the spiral correctly, that's because the spiral
> never ends, the detail increases towards the poles infinitely.
> That is, if I understood the description of the shape that I
> read a while ago correctly.

In an equiangular spiral (reverse Mercator projection of oblique
parallels), that would happen at both poles; TOK said only one.

What's the formula?

(Love the textures.)

-- 
          --  Anton Sherwood  --  http://www.ogre.nu/  --
"If nobody said anything unless he knew what he was talking about, 
a ghastly hush would descend upon the earth."  ---Sir Alan Herbert


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From: Christoph Hormann
Subject: Re: Almost Sphere Spirals (109 KB)
Date: 25 Jan 2002 07:35:43
Message: <3C510AC8.CB9FABE3@gmx.de>
Tor Olav Kristensen wrote:
> 
> I'm not sure if this image is finished
> or not now.
> 
> What do you think ?
> 
> Should I change something ?

If that surface structure is a normal you could make it part of the
isosurface geometry.  Apart from that, do you have 'normal on' in
radiosity?

> 
> I should probably mention that I had
> to "hand correct" the finished image
> somewhat at the sphere's "south pole".
> 
> (Because there seems to be some
> calculations that are not calculated
> correctly by POV-Ray. Increasing
> max_gradient or accuracy did not help
> at all.)

I think it's quite obvious that spiral structures lead to infinite
gradients which can't be rendered correctly under all circumstances.  

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: Gleb
Subject: Re: Almost Sphere Spirals (109 KB)
Date: 25 Jan 2002 10:51:07
Message: <3c51389b@news.povray.org>
Looks nice.

Will it form a whole sphere when combined

with the y-rotated other textured one?

Gleb


"Tor Olav Kristensen" <tor### [at] hotmailcom> wrote in message
news:3C508AF7.260EBD52@hotmail.com...
> What do you think ?


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From: R  Suzuki
Subject: Re: Almost Sphere Spirals (109 KB)
Date: 25 Jan 2002 15:00:51
Message: <3c517323@news.povray.org>
"Tor Olav Kristensen" wrote in message
> I'm not sure if this image is finished
> or not now.
> 
> What do you think ?

Nice image.

> I should probably mention that I had
> to "hand correct" the finished image
> somewhat at the sphere's "south pole".
> 
> (Because there seems to be some
> calculations that are not calculated
> correctly by POV-Ray. Increasing
> max_gradient or accuracy did not help
> at all.)

I tried to render your scene file posted in p.t.s-f
last month.  But I could not find any problem 
on the image.  Did you use the same function?

R. Suzuki


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From: Txemi Jendrix
Subject: Re: Almost Sphere Spirals (109 KB)
Date: 25 Jan 2002 22:21:06
Message: <3c51da52@news.povray.org>
"R. Suzuki" <r-s### [at] aistgojp> escribió en el mensaje
news:3c517323@news.povray.org...
> I tried to render your scene file posted in p.t.s-f
> last month.  But I could not find any problem
> on the image.  Did you use the same function?

Sorry, this has nothing to do with the question, but I wanted to ask you
something:

Today I have had a problem with a file you sent to p.t.s.f. (Iso quilt and
Carpet: 3 torii) in november 2001.
If I render it, I only obtain 2 torii and a black background.
I wanted the iso carpet for an imagen I'm working on, but it seems like it
has dissapear.
Maybe it's caused by the beta versions.
(AMD Athlon 600 Mhz, Win 98SE, Povray for Windows 3.5 beta 10).
Any help?
Thanks in advance.
--
Txemi Jendrix
tji### [at] euskalnetnet
http://www.geocities.com/txemijendrix


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From: R  Suzuki
Subject: Re: Almost ... Iso carpet
Date: 26 Jan 2002 08:05:11
Message: <3c526337@news.povray.org>
"Txemi Jendrix" wrote ..
> Sorry, this has nothing to do with the question, but I wanted to ask you
> something:
> 
> Today I have had a problem with a file you sent to p.t.s.f. (Iso quilt and
> Carpet: 3 torii) in november 2001.
> If I render it, I only obtain 2 torii and a black background.
> I wanted the iso carpet for an imagen I'm working on, but it seems like it
> has dissapear.
> Maybe it's caused by the beta versions.

Yes, it is caused by the syntax change.  I posted the revised one
in p.t.s-f as a reply of that message.  (I've added checker and hexagon
pattern in that scene)  I hope it is helpful for your project.

R. Suzuki


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