POV-Ray : Newsgroups : povray.general : Dumb iso question Server Time
7 Nov 2024 19:22:54 EST (-0500)
  Dumb iso question (Message 1 to 4 of 4)  
From: Xplo Eristotle
Subject: Dumb iso question
Date: 11 Jan 2002 14:41:04
Message: <3C3F3FE8.2EFC3676@unforgettable.com>
I've seen a lot of examples of isosurfaces that are supposedly made with
fractals and have kind of a round "whirled" look, like a screw or
seashell or cotton candy.. I don't know how to describe it better than
that, so hopefully someone knows what I mean.

Anyway, what sort of function is generating these?

-Xplo


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From: JRG
Subject: Re: Dumb iso question
Date: 11 Jan 2002 14:53:39
Message: <3c3f42c3@news.povray.org>
A fractal pigment?
POV-Ray has so many built in fractal patterns that you can use to displace an iso
plane.

--
#local j=text{ttf"arial""JRG".2,0}#local J=0;#while(J<10)#local R=0;#while
(R<2)#local G=0;#while(G<1)#if(inside(j<R,G.1>))object{j scale.025translate
<R-1G-J/20J/-40+2>pigment{rgb<9J>}}#debug"O"#else#debug" "#end#local G=G+
.025;#end#local R=R+.05;#debug"\n"#end#local J=J+1;#end// JRG

Home: http://digilander.iol.it/jrgpov  //New: Kitchen scene WIP

"Xplo Eristotle" <inq### [at] unforgettablecom> ha scritto nel messaggio
news:3C3F3FE8.2EFC3676@unforgettable.com...
> I've seen a lot of examples of isosurfaces that are supposedly made with
> fractals and have kind of a round "whirled" look, like a screw or
> seashell or cotton candy.. I don't know how to describe it better than
> that, so hopefully someone knows what I mean.
>
> Anyway, what sort of function is generating these?
>
> -Xplo


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From: Ken
Subject: Re: Dumb iso question
Date: 11 Jan 2002 21:26:51
Message: <3C3F9F12.8614C6B3@pacbell.net>
Xplo Eristotle wrote:
> 
> I've seen a lot of examples of isosurfaces that are supposedly made with
> fractals and have kind of a round "whirled" look, like a screw or
> seashell or cotton candy.. I don't know how to describe it better than
> that, so hopefully someone knows what I mean.
> 
> Anyway, what sort of function is generating these?

"These" are created using the built in julia fractal object.

e.g.

// create a 3-D slice of a 4-D julia fractal object
julia_fractal {
  <-0.083,0.0,-0.83,-0.025>
  quaternion
  cube
  max_iteration 8
  precision 20

 pigment{rgb 1}

}

-- 
Ken Tyler


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From: Christoph Hormann
Subject: Re: Dumb iso question
Date: 12 Jan 2002 03:54:45
Message: <3C3FF9CF.B9145F3@gmx.de>
JRG wrote:
> 
> A fractal pigment?
> POV-Ray has so many built in fractal patterns that you can use to displace an iso
> plane.
> 

This is usually not a good idea, because fractal patterns contain
non-continuous areas which lead to infinite gradients in isosurfaces.

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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