1 == Wed, Nov 25: Home, sweet home ==
3 {{http://i33.photobucket.com/albums/d52/mochifish/IMG_1566.jpg}}
5 == Exploring Julia in 4 dimensions ==
7 The discovery of the [[http://www.skytopia.com/project/fractal/mandelbulb.html | Mandelbulb]] awekened my old
10 So I took the time to re-encode my old rendering of the [[http://en.wikipedia.org/wiki/Quaternion | Quaternion]]
11 [[http://en.wikipedia.org/wiki/Julia_set | Julia set]] done with POV-Ray. Behold:
13 {{pictures/julia4D/julia4D-640x360.ogv | Quaternion Julia 4D fractal (640x360 @ 1200Kbit/s, Ogg Theora encoded)}}
15 The sound track is [[http://lite.modarchive.org/index.php?request=view_by_moduleid&query=59288 | UranChrome]],
16 an old-skool Amiga SoundTracker module composed by TorbJ0rn in 1989.
20 If your browser sucks at HTML5, you can directly download the video files, available in several formats:
22 || **Filename** || **Resolution**|| **Birate** ||**Video**||**Audio**||**Size**||
23 || [[pictures/julia4D/julia4D.ogv | julia4D.ogv (Ogg)]] || 1280x720 || 6000Kbit/s || Theora || Vorbis || 60MB ||
24 || [[pictures/julia4D/julia4D-640x360.ogv | julia4D-640x360.ogv (Ogg)]] || 640x320 || 1200Kbit/s || Theora || Vorbis || 13MB ||
25 || [[pictures/julia4D/julia4D.avi | julia4D .avi]] || 1280x720 || 6000Kbit/s || H.264 || - || 60MB ||
26 || [[pictures/julia4D/julia4D-640x360.avi | julia4D-640x360.avi]] || 640x360 || 1200kbit/s || H.264 || - || 12MB ||
28 === Rendering notes ===
30 It took about 2 weeks of computation on a dual-core machine to render the 2048 high resolution frames contained in 82 seconds of video.
31 My previous renderings at lower resolution and lower iteration count were much faster.
33 A The high iteration count actually makes the fractal surface a little too polverized to appreciate. Adding transparency
34 and gradients is another bad idea as it complicates things even more. If I find the time and motivation to re-render the
35 animation, I'll look for better balance.
37 In case someone wants to experiment, these are the [[pictures/julia4D/julia4D.pov | scene source]]
38 and [[pictures/julia4D/julia4D.ini | ini file]] I used.
40 === Video encoding notes ===
42 The files were encoded from a sequence of PNG frames generated by POV-Ray,
43 using **ffmpeg** and **mencoder**:
47 please mencoder 'mf://julia4D????.png' -mf fps=25 \
48 -ovc x264 -x264encopts bitrate=6000:pass=1:threads=2 -o julia4D.avi
51 please mencoder 'mf://julia4D????.png' -mf fps=25 -vf scale=640:360 \
52 -ovc x264 -x264encopts bitrate=1200:pass=1:threads=2 -o julia4D-640x360.avi
55 please ffmpeg -f image2 -i julia4D%04d.png \
56 -threads 2 -vb 6000k -vcodec libtheora -acodec libvorbis -f ogg julia4D.ogv \
57 -i UranChrome-fx-short.wav -acodec libvorbis -ab 96k -newaudio
60 please ffmpeg -f image2 -i julia4D%04d.png \
61 -threads 2 -s 640x360 -vb 1200k -vcodec libtheora -f ogg julia4D-640x360.ogv \
62 -i UranChrome-fx-short.wav -acodec libvorbis -ab 96k -newaudio
65 This is the software I have used:
68 MEncoder SVN-r29800-4.4.2 (C) 2000-2009 MPlayer Team
69 FFmpeg version SVN-r20372, Copyright (c) 2000-2009 Fabrice Bellard, et al.
72 x264-libs-0.26.20091026
75 The quality of the low-res Theora stream is noticeably lower than the corresponding low-res H.264. I don't know why.