In the Mandel pattern, one setting gives a cool image at both camera angle 20
and 20E-12, and both are super-quick (<< 5 sec) renders.

Chris Huff wrote:

> Then the number of iterations you used was large enough that you didn't
> need to change anything as you zoomed in...you might have gotten faster
> rendering if you reduced it at the higher scales.

I keep losing this argument with Warp.  My experience is that above a certain
number of iterations, it is an extremely fine color_map that is needed to see
all of the detail in the mandel pattern. The map was something like [1/250
Red][1/249 Blue]...    The rendering BTW zipped by, maybe a sec or two for
320x 240 when at angle 20E-12.

As I got to to a camera angle of 20E-12, I started to see "pixelation" of the
Mandel pattern.  I was told that this was the limit of the chip/PC/language
or something, not a limitation of the povray code, and I'll assert, not a
limitation of the Mandel math.   So once I had completed a lot of tweaking to
find an interesting x/z location, I just set up a simple code to reduce
camera angle and voila! I've got a cool zoomin' anim.  With the heteromf, it
is--again how do I say??-- not a recursive object like a sierpinski gadget.
My intuition was that under some parameters I would be able to set up a
camera zoom and magnify the heck out of it, getting cooler and cooler detail.
NOT SO with the heteromf. As you tell me, I'd need to keep fiddling with the
params as I zoomed deeper and deeper in.

> If you used infinite octaves in the multifractal, it would have an
> infinite level of detail...and take an infinite amount of time to
> compute 1 pixel.

Whereas in the Mandel, one setting gives a cool image at both camera angle 20
and 20E-12, and both are super-quick renders.  I was expecting heteromf to be
something like a sierpinski gadget, only in "crumbly sandy rock" form.

> > I once heard a precise definition of fractal as something that has
> > interesting detail at many orders of magnification.
>
> "many" != "infinite"
> And that doesn't seem very precise to me...it generally has to be
> self-similar as well.

Mandel has infinite; I didn't claim that all fractals had infinite.

> > I asked the question as I looked at the structures I'm making because
> > I'm beginning to doubt that it is fractal in the same sense or to the
> > same degree as the mandel.
>
> It is a fractal, in the same way the mandel pattern is a fractal. As for
> the "degree", that is a matter of the default settings...iterations of
> the mandel pattern or octaves of the multifractal.

Have you seen the rendering textbook where they show zooms of an island?
Blue water, crumbly brown granola bar peninsulas, looking the same at say 5
orders of magnitude.  Povray is so powerful that I'm betting I can do it with
existing Megapov code, sorry for haranguing you so much on this
subject...............

Post a reply to this message