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Jitter Fractals

june 2010
France

The image creation relies on a video feedback loop with rotation, zooming, position displacement and contrast/luminosity/saturation modifications. The input is the in-built webcam of the computer.

Lately, I modified the software to switch from CPU to GPU processing which really works faster and smoother, but I don’t get the same colors and textures…
I’ll try to find time to make another video.

How was MAX used?

The objects used in the CPU version are jit.op @op avg, jit.xfade, jit.rota, jit.brcosa, with matrix feedback.

Jitter Fractals

Apr 16, 2012 at 8:40am

Looks amazing – is there a patch you can share?

#262277
Apr 16, 2012 at 10:08am

I prefer to share the idea more than an already made patch.
It’s very simple technically.

I don’t want to point people to one direction using feedback technique.
If you really don’t find a way to create a video feedback loop, I could share a way to do it…

Thanks for your attention and replay by the way.

#262278
Apr 16, 2012 at 8:44pm

very filthy

#262279
Apr 20, 2012 at 10:56pm

nice!

#262280
Jan 22, 2013 at 9:33pm

Hey awesome patch, do you mind explaining how this matrix feedback works?

#262281
Jan 22, 2013 at 10:56pm

to create a feedback loop in jitter, there’s a little trick, like in msp you need [send~] and [receive~]
I just opened my CPU version and without doubt it’s way better (but way slower too)

so for the feedback loop you need [jit.xfade @in2_name x @out-name x].
the xfade message will control the feedback amount.

you connect your video input to [jit.xfade] in1 then its output to the video processing (in this situation [jit.rota @boundmode 4] and [jit.brcosa]) and the processing output back to [jit.xfade] in2.
a [jit.brcosa] on the output is useful to bring back the luminosity/contrast the feedback loop removes.
voilà.

if you don’t get it, don’t hesitate to ask questions, if you find any nice results, show us.
have fun.

#262282
Jan 31, 2013 at 3:06pm

I just started using Max/Jitter and this has to be the coolest thing I’ve seen so far come from it. I just hope my projects turn out to be this sweet.

#262283
Feb 1, 2013 at 4:24am

thank you.

#262284
Oct 26, 2013 at 10:37pm

Hi Bertrand!

Kudos on the awesome patch. I have been interested in video feedback for quite some time now, and am finally trying to create ‘digital feedback’ as opposed to analog using Jitter. I’m just curious – did you manipulate the parameters (zoom, position displacement, etc.) in real time, or were they set to static numbers? I’m a Jitter newbie, so any tips you can provide are most appreciated. Keep up the good work!

#269239
Oct 27, 2013 at 3:23am

I can tell you quite clearly that the jit.rota was manipulated quite a lot in realtime.

Hope this helps.

#269242
Oct 27, 2013 at 9:26am

Thanks… I have copied the attribute buttons for the jit.rota object from the jit.rota help file, but I am unsure how to set things up so that these values can be manipulated in real time – right now I am only able to click and drag on the numbers, or enter them manually. I have a midi controller (M Audio Axiom 61) – is there a way to map knobs to control these parameters in real time? Or are there other objects in Max that are well-suited for this purpose? (I’m sure there are).

Thanks again for any insight!

#269263
Oct 27, 2013 at 11:11am

yeah, those attribute things are problematic, to say the least – they don’t save with presets either, IIRC. Great for prototyping, bad for patching…

do the traditional method instead; message box with “anchor_x $1″ and integers coming in there.

#269270
Oct 27, 2013 at 11:35am

wow! great great trick! thanks a lot, awesome!!!

Btw, can someone please explain to me the function of “@in2_name x” and “@out-name x” in jit.xfade? Of course I checked the reference but can’t understand what is going on in this case…

@DCARDELLO: check Max tutorials—>MIDI—>Basics. Or check ctlin object.

#269273
Oct 27, 2013 at 11:42am

it seems it works in the same way without “@in2_name x” and “@out-name x” in jit.xfade…

#269275
Oct 27, 2013 at 12:46pm

@T the problem that DCARDELLO is describing is the attrui objects that Max creates. They’re great for somethings, but can’t really be controlled sensibly using anything other than a mouse.

#269282
Oct 27, 2013 at 12:49pm

Oh, and as a tip to the uninitiated, I think the key tweak here is [jit.rota @interp 1]

#269284
Oct 27, 2013 at 9:18pm

appreciate the tips, all. yes – I am a newbie. to be fixed soon >.<

#269307
Nov 15, 2013 at 11:21am

I’m also trying to get a fractal effect like this by webcam input, I followed the hints but cannot get the fracal effect. can somebody see what i’m doing wrong or hint me in the right direction?

Attachments:
  1. feedback.maxpat
#271336
Nov 15, 2013 at 12:58pm

don’t really know how exactly you’d get fractals out of video, but you can get video feedback like so:

<code>

– Pasted Max Patch, click to expand. –

</code>

#271341
Nov 21, 2013 at 6:31am

I would say the fractals are working like this video but based on the buffering in max and changing the jit.rota function inputs. If someone makes something similar, do share!

#271960
Nov 21, 2013 at 9:30am

Wow, just did a small patch with xfade, rota and brcosa, here’s me playing only with the theta param of jit.rota:

#271976
Nov 21, 2013 at 5:29pm

Simple one using jit.op (max) and jit.rota. Boundmode seems to be key to me. https://www.youtube.com/watch?v=UQmwQtn0d9g

#272009
Nov 22, 2013 at 8:18am

Have fun !

<code>

– Pasted Max Patch, click to expand. –

</code>

#272057

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