POV-Ray : Newsgroups : povray.binaries.images : More trefoil doodles Server Time
29 Mar 2024 11:50:33 EDT (-0400)
  More trefoil doodles (Message 1 to 9 of 9)  
From: Tor Olav Kristensen
Subject: More trefoil doodles
Date: 2 Feb 2023 19:55:00
Message: <web.63dc5af8bffce341d0d6e0d389db30a9@news.povray.org>
A few days ago Paolo Gibellini asked me to doodle some more.

Here are the results of some experiments I have done since I started
looking at Droj's problem in the "2D function to 3D tube" thread.

--
Tor Olav
http://subcube.com
https://github.com/t-o-k


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Attachments:
Download 'some trefoil tubes.jpg' (1008 KB)

Preview of image 'some trefoil tubes.jpg'
some trefoil tubes.jpg


 

From: Tor Olav Kristensen
Subject: Re: More trefoil doodles
Date: 2 Feb 2023 20:05:00
Message: <web.63dc5d8a2ed7b75ed0d6e0d389db30a9@news.povray.org>
"Tor Olav Kristensen" <tor### [at] TOBEREMOVEDgmailcom> wrote:
> A few days ago Paolo Gibellini asked me to doodle some more.
>
> Here are the results of some experiments I have done since I started
> looking at Droj's problem in the "2D function to 3D tube" thread.

It seems that the attached image was to big for the Image Digest preview.

Here is a smaller version that I hope will show up.

--
Tor Olav
http://subcube.com
https://github.com/t-o-k


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Attachments:
Download 'some trefoil tubes 1200x900.jpg' (286 KB)

Preview of image 'some trefoil tubes 1200x900.jpg'
some trefoil tubes 1200x900.jpg


 

From: Thomas de Groot
Subject: Re: More trefoil doodles
Date: 3 Feb 2023 02:20:12
Message: <63dcb5ac$1@news.povray.org>
Op 03/02/2023 om 02:04 schreef Tor Olav Kristensen:
> "Tor Olav Kristensen" <tor### [at] TOBEREMOVEDgmailcom> wrote:
>> A few days ago Paolo Gibellini asked me to doodle some more.
>>
>> Here are the results of some experiments I have done since I started
>> looking at Droj's problem in the "2D function to 3D tube" thread.
> 
> It seems that the attached image was to big for the Image Digest preview.
> 
> Here is a smaller version that I hope will show up.
> 

I got both without problems (Thunderbird). Beautiful things indeed!

-- 
Thomas


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From: jr
Subject: Re: More trefoil doodles
Date: 3 Feb 2023 05:45:00
Message: <web.63dce4e42ed7b75efbdc16836cde94f1@news.povray.org>
hi,

"Tor Olav Kristensen" <tor### [at] TOBEREMOVEDgmailcom> wrote:
> ...
> Here are the results of some experiments ...

if the "honey-gold" colouring of the centre left object was more even, it'd look
like an "artisan" churro, bought in a (Spanish) street market.  :-)


regards, jr.


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From: Bald Eagle
Subject: Re: More trefoil doodles
Date: 3 Feb 2023 06:25:00
Message: <web.63dcee2c2ed7b75e1f9dae3025979125@news.povray.org>
"Tor Olav Kristensen" <tor### [at] TOBEREMOVEDgmailcom> wrote:
> A few days ago Paolo Gibellini asked me to doodle some more.
>
> Here are the results of some experiments I have done since I started
> looking at Droj's problem in the "2D function to 3D tube" thread.

Those are looking good.  New outfits for an old classic  :)

I haven't had time to play with this any further - but was wondering about
rendering flat ribbons (offset curves), and what happens when the radius/offset
becomes so large that one gets self-intersection.


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From: Tor Olav Kristensen
Subject: Re: More trefoil doodles
Date: 4 Feb 2023 18:00:00
Message: <web.63dee2752ed7b75ed0d6e0d389db30a9@news.povray.org>
Thomas de Groot <tho### [at] degrootorg> wrote:
> Op 03/02/2023 om 02:04 schreef Tor Olav Kristensen:
> > "Tor Olav Kristensen" <tor### [at] TOBEREMOVEDgmailcom> wrote:
> >> A few days ago Paolo Gibellini asked me to doodle some more.
> >>
> >> Here are the results of some experiments I have done since I started
> >> looking at Droj's problem in the "2D function to 3D tube" thread.
> >
> > It seems that the attached image was to big for the Image Digest preview.
> >
> > Here is a smaller version that I hope will show up.
> >
>
> I got both without problems (Thunderbird). Beautiful things indeed!

Ok. It was the web interface that didn't want to show the first attached image.

Thank you Thomas.

--
Tor Olav
http://subcube.com
https://github.com/t-o-k


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From: Tor Olav Kristensen
Subject: Re: More trefoil doodles
Date: 4 Feb 2023 18:25:00
Message: <web.63dee84a2ed7b75ed0d6e0d389db30a9@news.povray.org>
"Bald Eagle" <cre### [at] netscapenet> wrote:
> "Tor Olav Kristensen" <tor### [at] TOBEREMOVEDgmailcom> wrote:
> > A few days ago Paolo Gibellini asked me to doodle some more.
> >
> > Here are the results of some experiments I have done since I started
> > looking at Droj's problem in the "2D function to 3D tube" thread.
>
> Those are looking good.  New outfits for an old classic  :)

Thank you

I think that it's interesting that adding many small details or deformations
to the surface can make its "outfit" (or texture ?) seem quite different,
even if the real textures are just plain pigments with the default finish.

> I haven't had time to play with this any further - but was wondering about
> rendering flat ribbons (offset curves), and what happens when the radius/offset
> becomes so large that one gets self-intersection.

Its self intersection happens in a not so nice way, as you can see in the
attached image.

--
Tor Olav
http://subcube.com
https://github.com/t-o-k


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Attachments:
Download 'parametricmesh_17_01.png' (45 KB)

Preview of image 'parametricmesh_17_01.png'
parametricmesh_17_01.png


 

From: Bald Eagle
Subject: Re: More trefoil doodles
Date: 4 Feb 2023 19:50:00
Message: <web.63defce62ed7b75e1f9dae3025979125@news.povray.org>
"Tor Olav Kristensen" <tor### [at] TOBEREMOVEDgmailcom> wrote:

> I think that it's interesting that adding many small details or deformations
> to the surface can make its "outfit" (or texture ?) seem quite different,
> even if the real textures are just plain pigments with the default finish.

It doesn't take much - a lot of what we "see" gets made up in our head. And it
explains why all those little visual cues make it so hard to mimic realistic
textures and why so much cgi seems "flat".

I meant like a sine wave, with the triangles rendered in the xy plane, and not
in a tube - like if you only used 0 and pi in the mesh loop.  As the offset
curve gets farther away from one peak, it approaches another peak's offset.


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From: Paolo Gibellini
Subject: Re: More trefoil doodles
Date: 16 Feb 2023 19:12:33
Message: <63eec671$1@news.povray.org>
Il 03/02/2023 01:53, Tor Olav Kristensen wrote:

The results are really stunning!

Paolo


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