POV-Ray : Newsgroups : povray.general : New interesting class of shapes to model Server Time
12 Dec 2024 18:09:20 EST (-0500)
  New interesting class of shapes to model (Message 1 to 5 of 5)  
From: yesbird
Subject: New interesting class of shapes to model
Date: 15 Sep 2024 04:21:22
Message: <66e69902$1@news.povray.org>
Hi,

I found following paper this morning, authors are offering new
approach to space filling, calling it a 'soft tilings':

https://academic.oup.com/pnasnexus/article/3/9/pgae311/7754698?login=false

Looks very attractive and guess, this objects are waiting for SDL
implementation ;)
--
YB


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From: Ilya Razmanov
Subject: Re: New interesting class of shapes to model
Date: 16 Sep 2024 03:39:13
Message: <66e7e0a1$1@news.povray.org>
On 15.09.2024 11:21, yesbird wrote:
> Hi,
> 
> I found following paper this morning, authors are offering new
> approach to space filling, calling it a 'soft tilings':
> 
> https://academic.oup.com/pnasnexus/article/3/9/pgae311/7754698?login=false
> 

I don't quite see an "innovation". In rectangular bitmap tiling there is 
a well known trick based on "wraparound" processing, allowing to do 
anything, including distortions, producing what the authors called 
"soft" tiling (surely, tiling symmetry remains the same but it's harder 
to see). I did it for web backgrounds before it became a mainstream ;-) 
In fact, I did something like this for "puzzle" preset for my POVRay 
Mosaic, there "thingie" object is defined as:

#declare pin_rad = 0.2;
#declare pin_off = 0.1;
#declare thingie = difference {
     union {
         box{
             <-0.5, -0.5, -0.5>, <0.5, 0.5, 0.5>
         }
         cylinder {
             <-0.5-pin_off, 0, -0.5>, <-0.5-pin_off, 0, 0.5>, pin_rad
         }
         cylinder {
             <0, -0.5-pin_off, -0.5>, <0, -0.5-pin_off, 0.5>, pin_rad
         }
     }
     union {
         cylinder {
             <0.5-pin_off, 0, -1>, <0.5-pin_off, 0, 1>, pin_rad
         }
         cylinder {
             <0, 0.5-pin_off, -1>, <0, 0.5-pin_off, 1>, pin_rad
         }
     }
   scale 0.99
}

  Easy to see that cylinders for pins at one side and cylinders for 
holes at another side are internally linked though "pin_off" variable, 
providing wraparound movement. Now, if one dare to replace cylinders 
with prism control points...

-- 
Ilyich the Toad
https://dnyarri.github.io/


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From: Ilya Razmanov
Subject: Re: New interesting class of shapes to model
Date: 17 Sep 2024 10:52:49
Message: <66e997c1$1@news.povray.org>
On 15.09.2024 11:21, yesbird wrote:
> Hi,
> 
> I found following paper this morning, authors are offering new
> approach to space filling, calling it a 'soft tilings':

BTW, speaking of tiling (although not too soft): recently I've released 
small update to my POVRay Mosaic, besides some small programs 
improvements here and there it contains some new presets in POVRay .inc 
files. Among them there's a tileable one:

https://github.com/Dnyarri/POVmosaic/blob/main/presets/44_surprise.inc

regarding which I'm still not sure whether it was a good idea to add it 
to repo or not...

-- 
Ilyich the Toad
https://dnyarri.github.io/


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From: kurtz le pirate
Subject: Re: New interesting class of shapes to model
Date: 20 Sep 2024 11:22:08
Message: <66ed9320$1@news.povray.org>
On 16/09/2024 09:39, Ilya Razmanov wrote:
> I don't quite see an "innovation". In rectangular bitmap tiling there is 
> a well known trick based on "wraparound" processing, allowing to do 
> anything, including distortions, producing what the authors called 
> "soft" tiling (surely, tiling symmetry remains the same but it's harder 
> to see). I did it for web backgrounds before it became a mainstream ;-) 
> In fact, I did something like this for "puzzle" preset for my POVRay 
> Mosaic, there "thingie" object is defined as:

Ho, yes. Well know tricks
Here, a "thingie plane" based on your object ;)



-- 
Kurtz le pirate
Compagnie de la Banquise


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From: Ilya Razmanov
Subject: Re: New interesting class of shapes to model
Date: 20 Sep 2024 14:12:56
Message: <66edbb28$1@news.povray.org>
On 20.09.2024 18:22, kurtz le pirate wrote:
> On 16/09/2024 09:39, Ilya Razmanov wrote:

> Ho, yes. Well know tricks
> Here, a "thingie plane" based on your object ;)

With recent update, I added a couple more presets using similar idea, 
like that one:


#local timerand = seed(int(now*100000)); // Seeding time  {#886600, 1}
#local a = 1.5;  // Overall offset factor, exceeding 2.0 may lead to 
weird effects

// Critical part:                                   {#880000, 2}
#declare of26 = <a * (rand(timerand) - 0.5), a * (rand(timerand) - 0.5)>;
#declare of48 = <a * (rand(timerand) - 0.5), a * (rand(timerand) - 0.5)>;

#declare thingie = prism{conic_sweep linear_spline -1, 0, 9,
  <-1, -1>, <0, -1> + of26, <1, -1>,
  <1, 0> + of48,
  <1, 1>, <0, 1> + of26, <-1, 1>,
  <-1, 0> + of48,
  <-1, -1>}

Funny thing is, it works :-)

-- 
Ilyich the Toad
https://dnyarri.github.io/


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