POV-Ray : Newsgroups : povray.advanced-users : plasma, bozo or whatever, just help me out Server Time
27 Dec 2024 05:24:26 EST (-0500)
  plasma, bozo or whatever, just help me out (Message 1 to 8 of 8)  
From: Eitan Tal
Subject: plasma, bozo or whatever, just help me out
Date: 1 Oct 1999 06:29:34
Message: <37F48CB1.E820B562@netvision.net.il>
I remember there's such fractal called plasma (bunch of colors
toghether) that is similar to bozo. I want to have the formula of it

I still know that fractint (fractal maker) still exists and if any of
you
are interested, I think I have it somewhere on my site

I tried to make up something that should be quite similar but for some
reason it doesn't work as expected. it is based on changes (visual basic
language)


Dim matrix(32, 32)
Dim y
Dim x
Dim c
Function matrix9(x, y, val)
matrix(x, y) = val
matrix(x + 1, y) = val
matrix(x - 1, y) = val
matrix(x, y + 1) = val
matrix(x, y - 1) = val
matrix(x + 1, y + 1) = val
matrix(x - 1, y + 1) = val
matrix(x + 1, y - 1) = val
matrix(x - 1, y - 1) = val
End Function
Private Sub Command1_Click()
Command3.Enabled = False
Command4.Enabled = False
matrix(1, 1) = Int(Rnd * 2)
For y = 1 To 31
  If Int(Rnd * VScroll1.Value) = 0 Then matrix(1, y + 1) =
MyNot(matrix(1, y)) Else matrix(1, y + 1) = matrix(1, y)
Next
For x = 1 To 31
  If Int(Rnd * VScroll1.Value) = 0 Then matrix(x + 1, 1) =
MyNot(matrix(x, 1)) Else matrix(x + 1, 1) = matrix(x, 1)
Next
'For x = 2 To 31
'  select case matrix(
'For y = 1 To 32
'  For x = 1 To 32
'    matrix(x, y) = Int(Rnd * 2)
'  Next
'Next
'For y = 1 To 31
'  For x = 1 To 31
'    If matrix(x, y + 1) + matrix(x - 1, y) + matrix(x + 1, y) +
matrix(x, y - 1) < 3 Then matrix(x, y + 1) = 0: matrix(x - 1, y) = 0:
matrix(x + 1, y) = 0: matrix(x, y - 1) = 0 Else a = matrix9(x, y, 1)
'  Next
'Next
'the last part of the randomization - displaying the matrix
For y = 1 To 32
  For x = 1 To 32
    Image2(getindex(x, y)).Picture = Form2.image1(matrix(x, y)).Picture
  Next
Next
Command2.Enabled = True
End Sub

Function MyNot(N)
If N = 1 Then N = 0 Else N = 1
MyNot = N
End Function
Function getindex(x, y)
getindex = x + (32 * y) - 32
End Function


Private Sub Command2_Click()
Command3.Enabled = True
Command4.Enabled = True
For y = 2 To 32
  For x = 2 To 32
    a = matrix(x - 1, y)
    b = matrix(y - 1, x)
    Select Case a + b
      Case 0
        If Int(Rnd * 2 * VScroll1.Value) = 1 Then c = MyNot(c)
      Case 1
        If Int(Rnd * VScroll1.Value) = 1 Then c = MyNot(c)
      Case 2
        If Int(Rnd * vscroll2.Value * VScroll1.Value) = 1 Then c =
MyNot(c)
    End Select
    matrix(x, y) = c
  Next
'  Exit For
Next
For y = 1 To 32
  For x = 1 To 32
    Image2(getindex(x, y)).Picture = Form2.image1(matrix(x, y)).Picture
  Next
Next
End Sub

Private Sub VScroll1_Change()
Label1.Caption = "rnd =" + Str$(VScroll1.Value)
Command1.Enabled = 1
End Sub


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From: Ken
Subject: Re: plasma, bozo or whatever, just help me out
Date: 1 Oct 1999 06:33:26
Message: <37F48D88.DEF3CCBB@pacbell.net>
Eitan Tal wrote:
> 
> I remember there's such fractal called plasma (bunch of colors
> toghether) that is similar to bozo. I want to have the formula of it
> 
> I still know that fractint (fractal maker) still exists and if any of
> you
> are interested, I think I have it somewhere on my site
> 
> I tried to make up something that should be quite similar but for some
> reason it doesn't work as expected. it is based on changes (visual basic
> language)

I will forward a fractal plasma macro to you created by Warp through email.

-- 
Ken Tyler
1100+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html


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From: Nieminen Juha
Subject: Re: plasma, bozo or whatever, just help me out
Date: 1 Oct 1999 06:58:27
Message: <37f493d3@news.povray.org>
Eitan Tal <eit### [at] netvisionnetil> wrote:
: I remember there's such fractal called plasma (bunch of colors
: toghether) that is similar to bozo. I want to have the formula of it

  The plasma in fractint (and my macro) is calculated iteratively using
random steps. There's no (non-recursive) formula f(x,y) which returns the
height at the point (x,y) according to the plasma.

  (Well, strictly speaking there _might_ be such formula, but I have no idea
how does it look and I have the feeling that it would be quite complicated).

  If the iterative version is enough, one algorithm can be found in my
macro (which I think Ken sent to you).

-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/


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From: Eitan Tal
Subject: Re: plasma, bozo or whatever, just help me out
Date: 1 Oct 1999 08:07:58
Message: <37F4A3C2.D0A55C38@netvision.net.il>
that is not all; that's only the CODE part of the .frm file,
there are thousands of image objects + form2 + pictures.

Ken wrote:

> Eitan Tal wrote:
> >
> > I remember there's such fractal called plasma (bunch of colors
> > toghether) that is similar to bozo. I want to have the formula of it
> >
> > I still know that fractint (fractal maker) still exists and if any of
> > you
> > are interested, I think I have it somewhere on my site
> >
> > I tried to make up something that should be quite similar but for some
> > reason it doesn't work as expected. it is based on changes (visual basic
> > language)
>
> I will forward a fractal plasma macro to you created by Warp through email.
>
> --
> Ken Tyler
> 1100+ Povray, Graphics, 3D Rendering, and Raytracing Links:
> http://home.pacbell.net/tylereng/index.html


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From: Eitan Tal
Subject: Re: plasma, bozo or whatever, just help me out
Date: 1 Oct 1999 08:09:33
Message: <37F4A421.8C5B94F0@netvision.net.il>
I know the plasma is a function, I can't seem to see anything near that
so I am trying to think of something near it.

all fractals that fractint uses are functions and pretty short.

Nieminen Juha wrote:

> Eitan Tal <eit### [at] netvisionnetil> wrote:
> : I remember there's such fractal called plasma (bunch of colors
> : toghether) that is similar to bozo. I want to have the formula of it
>
>   The plasma in fractint (and my macro) is calculated iteratively using
> random steps. There's no (non-recursive) formula f(x,y) which returns the
> height at the point (x,y) according to the plasma.
>
>   (Well, strictly speaking there _might_ be such formula, but I have no idea
> how does it look and I have the feeling that it would be quite complicated).
>
>   If the iterative version is enough, one algorithm can be found in my
> macro (which I think Ken sent to you).
>
> --
> main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
> ):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/


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From: Mark Wagner
Subject: Re: plasma, bozo or whatever, just help me out
Date: 2 Oct 1999 00:17:53
Message: <37f58771@news.povray.org>
Eitan Tal wrote in message <37F4A421.8C5B94F0@netvision.net.il>...
>I know the plasma is a function, I can't seem to see anything near that
>so I am trying to think of something near it.
>
>all fractals that fractint uses are functions and pretty short.

Try looking at the Fractint source code for the formula.  Visual Basic and C
are similar enough that you should be able to figure out how Fractint
creates plasma clouds.

Mark


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From: Peter Popov
Subject: Re: plasma, bozo or whatever, just help me out
Date: 2 Oct 1999 16:20:23
Message: <2Gf2NzofWaVIHLKa2o9z0NIRXJZX@4ax.com>
On Fri, 01 Oct 1999 14:08:01 +0200, Eitan Tal
<eit### [at] netvisionnetil> wrote:

>I know the plasma is a function, I can't seem to see anything near that
>so I am trying to think of something near it.
>
>all fractals that fractint uses are functions and pretty short.

I suggest you look into the FractInt docs. The plasma you are asking
about is constructed by a combination of recursive subdivision, linear
interpolation and inverse-distance-based random error. If you have a
slow enough computer (a 486-66 for example) you can actually see how
FractInt draws it and you'll get a better idea.


Peter Popov
ICQ: 15002700


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From: Nieminen Juha
Subject: Re: plasma, bozo or whatever, just help me out
Date: 4 Oct 1999 04:38:18
Message: <37f8677a@news.povray.org>
Eitan Tal <eit### [at] netvisionnetil> wrote:
: I know the plasma is a function, I can't seem to see anything near that
: so I am trying to think of something near it.

: all fractals that fractint uses are functions and pretty short.

  But they are _recursive_ functions (which are calculated iteratively, ie.
with loops).
  To my knowledge there's no non-recursive function which you calculate just
once and you get the plasma color at a specific coordinate pair.
  For example, the function that calculates the Mandelbrot set is recursive.
In theory you have to calculate the recursion an infinite number of times
for some points before you can be sure that it actually belongs to the set.
In practice you calculate it only a certain number of times (ie. you make
just an approximation).
  There exist no function that you calculate only once and that gives you
the answer whether the point belongs to the set or not.

  Now I quote myself again:

:>   If the iterative version is enough, one algorithm can be found in my
:> macro (which I think Ken sent to you).

-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/


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