Subject: Re: I don't understand this
From: Robert Ackermann <[email-masked]>
To: don lancaster <[email-masked]>
Date: Tue, 22 Mar 2016 09:18:18 -0700

Thank you for sharing this.  Very interesting.

No, I agree, not fractal (i.e., not self-similar at different scale)

Although not stated clearly, most of the math muscle-flexing in the 
first few paragraphs appears to be justification for combining the tine 
operations you select to apply into one function that applies them all 
in one call, that is, there will be one combined f(x,y) that returns a 
displaced x,y for any x,y on the plane. This allows displacing the 
points as they are produced.  For example, if you use (but don't have 
to) the Minsky Circle algorithm for the first (bottom) circle: as the 
algorithm produces each x,y pair the point can be passed into the 
combined f(x,y) at that time to produce the displaced point.  The points 
are saved just long enough to do the fill operation.  Then the next 
circle points are generated, distorted, and filled.  And, so on...  So, 
to be clear, the displacements that result in the final marbled image 
are done to the points as the circles are produced.

I have not studied the code (which will be difficult for me because I do 
not code in PostScript) so would not be surprised if I were wrong about 
some aspect of this.

The tine operations themselves look to be fairly straightforward (well, 
at least the vertical and horizontal linear non-curved ones do).  I may 
later experiment with combining a few of them into one function and then 
applying them to a circle -- probably in Python, not PostScript.  If I 
do, I will share...

Best,
Rob

On 03/20/2016 09:51 AM, don lancaster wrote:
> But it appears stunningly brilliant and potentially ridiculously compact.
>
> http://people.csail.mit.edu/jaffer/Marbling/Mathematics
>
> http://www.tinaja.com/psutils/stoner1x.pdf
> http://www.tinaja.com/psutils/stoner1x.psl
>
> He apparently starts with a pile of concentric Minsky Circles and then
> applies a hippy dippy THC transform to them.
>
> I am completely lost over how the transform works.
>
> The final PostScript code seems to be a thick pile of Raggedy Anne 
> pancakes.
> Possibly not marbeling at all. I can't see any fractal anything in the 
> code.