[NetBehaviour] 319 of 1200 lines done [time taken: 8009.708]

James Morris jwm.art.net at gmail.com
Thu Nov 18 10:02:52 CET 2010


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total 3.3M
-rw-r--r-- 1 gensys gensys 3.5K Nov 18 00:39 ap1.mdz
-rw-r--r-- 1 gensys gensys  589 Nov 18 01:12 ap10_lozenge.log
-rw-r--r-- 1 gensys gensys 3.8K Nov 18 01:01 ap10_lozenge.mdz
-rw-r--r-- 1 gensys gensys 7.4K Nov 18 01:12 ap10_lozenge.png
-rw-r--r-- 1 gensys gensys 3.5K Nov 18 00:39 ap2.mdz
-rw-r--r-- 1 gensys gensys 3.5K Nov 18 00:39 ap3.mdz
-rw-r--r-- 1 gensys gensys 3.8K Nov 18 00:39 ap4.mdz
-rw-r--r-- 1 gensys gensys 3.8K Nov 18 00:40 ap5.mdz
-rw-r--r-- 1 gensys gensys 3.1M Nov 18 06:45 ap6-delicate-1600.png
-rw-r--r-- 1 gensys gensys  97K Nov 18 00:45 ap6-delicate-sml.png
-rw-r--r-- 1 gensys gensys  598 Nov 18 06:45 ap6-delicate.log
-rw-r--r-- 1 gensys gensys 3.8K Nov 18 00:40 ap6-delicate.mdz
-rw-r--r-- 1 gensys gensys 8.4K Nov 18 01:12 ap6-delicate.png
-rw-r--r-- 1 gensys gensys 3.8K Nov 18 00:45 ap7.mdz
-rw-r--r-- 1 gensys gensys 3.8K Nov 18 00:48 ap8_or7.mdz
-rw-r--r-- 1 gensys gensys    0 Nov 18 06:45 ap9_trees_valley-1600.png
-rw-r--r-- 1 gensys gensys  790 Nov 18 08:31 ap9_trees_valley.log
-rw-r--r-- 1 gensys gensys 3.8K Nov 18 00:52 ap9_trees_valley.mdz
-rw-r--r-- 1 gensys gensys 7.0K Nov 18 01:12 ap9_trees_valley.png
-rw-r--r-- 1 gensys gensys 3.0K Nov 18 00:43 delicate.map
-rwxr-xr-x 1 gensys gensys  307 Nov 18 01:14 render

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#!/bin/bash

WIDTH=1600
AA=3
THREADS=16


FILES="ap6-delicate.mdz ap9_trees_valley.mdz ap10_lozenge.mdz"

for FILE in $FILES
do
OUT=${FILE%.mdz}-${WIDTH}.png
LOG=${FILE%.mdz}.log
../mdz --load-settings $FILE            \
        --log-file $LOG                 \
        --width $WIDTH                  \
        --anti-alias $AA                \
        --threads $THREADS              \
        --render $OUT

done

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calculating...
1200 of 1200 lines done [time taken: 19858.867]
calculating...
 255 of 1200 lines done [time taken: 6382.448]

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# http://jwm-art.net/mdz/
settings
family mandelbrot
fractal mandelbrot
depth 25000
aspect 1.33333333333333325932
colour-scale 0.54296875000000000000
colour-interpolate yes
multi-precision yes
multi-rounding no
precision 256
cx -1.746523647556323358260933898234246872191302782100383132837204732135041740546247
cy 5.812744350494126658510690006578897014527628978896906190198203555412730674718170e-8
size 1.479855761444640639149160554140432063171153009417107937511478029346403610468850e-41
#xmin @NaN@
#xmax @NaN@
#ymax @NaN@
palette-offset 55
render-time 19858.867s
saved-image ap6-delicate-1600.png

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Notice how ap6-delicate-1600.png was rendered... multi-precision is on
and using 256 bits of precision. This explains the render time of five
and a half hours. Well no it doesnt. If that explains the render time,
how long would it have taken me to find that particular spot in the
image? No, the image dimension (notice from the command line output
captured here, 1200 of 1200 lines done [time taken: 19858.867]). To
explore and locate a point to render, a 240 x 120 image size was used.

Now, 256 bits of precision is fine for a 240 x 120 pixel image, but
what about 1600 x 1200 pixels? Surely that will need more precision
because the spacing between the pixels will be smaller and smaller
numbers need more precision to be stored?

No, it turns out the fractal is so small anyway that the difference
between 1600 pixels and 240 pixels is a bit like  worrying about the
difference in size between the... I don't know. What is so small that
it's 1.479... with 41 zeros in front of it? A monokey side case on an
e-road in Germany? So at the size of numbers where 256 bits are
needed, the extra strain of increasing the resolution from 240 pixels
to 1600 is a bit like having a telescope orbiting the earth instead of
high up on a mountain. It's only going to help you see more clearly,
but the distance is cancelled out by the vastness of what is to be
viewed.

Makes it worth it that the final image looks so jaded.

http://jwm-art.net/image/ap6-delicate-1600.png

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 319 of 1200 lines done [time taken: 8009.708]

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-- 
_
: http://jwm-art.net/
-audio/image/text/code/

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