[NetBehaviour] Disaggregate Flocking?

Paul Hertz ignotus at gmail.com
Sat May 6 11:42:35 CEST 2023

I think some of my flocking images might interest you, as might the code
behind them. I implemented Craig Reynolds' Boids Algorithm building on code
by Daniel Shiffman. I wanted to use the simulated flocks for drawing, not
unlike your multiple image bird paths.

Flocking and steering algorithms commonly use 3 or more parameters.
Separation, alignment, and cohesion are the principal ones, to which
field-of-view and other variables may be added. Separation refers to the
minimum distance between boids, alignment is the tendency to face the same
direction, cohesion is the distance over which flock cohere, and
field-of-view is the forward-facing angle within which boids "see" other
boids. Field-of-view can give rise to V-formations, so it's an interesting
addition. I didn't use it in my implementation.

Tweaking the variables (and their variability) can give you vastly
different behaviors, Boids with low cohesion distance and large alignment
distance have trouble flocking, for instance. They make very tangled paths
and never form a cloud of boids moving in the same direction. Much of the
variation you're suggesting could happen within a simulation, just by
varying the parameters.

Here's a selection from the first series I created:
https://flic.kr/s/aHsjzxxd6B. "Land Lines" is an homage to Colette and Jeff
Bangert, pioneers of algorithmic art.
A later series, https://flic.kr/s/aHskAU7qF2, used video tracking to move
the boids. The code allows you to wave your hands to move the boids, or you
can point the camera at traffic, to capture the flow, or whatever. I
installed it in a gallery pointing at foot traffic in the Chicago loop back
in 2016. Here's an example: https://vimeo.com/42786680.

The code for the version with video tracking still works on my new MacBook,
so it might be worth a try: https://github.com/Ignotus-mago/Flocking. If
you want to try it out, I can help you with the installation.

// Paul

The first series

On Fri, May 5, 2023 at 5:14 PM Alan Sondheim via NetBehaviour <
netbehaviour at lists.netbehaviour.org> wrote:

> (might be useful re: Finsbury Park?)
> Disaggregate Flocking?
> https://youtu.be/R-J_KZI3dvY video
> Rather than swarming or flocking behavior, I'd like to call what
> I see in these images aggregate behavior or disaggregate
> behavior - what I mean is that the behavior is largely random
> that the gatherings are very crude and so very loosely bound
> that they fall apart constantly; they are "somewhat" incoherent.
> I wonder if instead of an overall flocking behavior algorithm
> algorithm one might consider or one might think about the
> possibilities of local geodesics that each bird follows that
> would have some relationship to avoidance behavior and to
> coagulation behavior but at the same time would not call this
> one way another into an overall shape such as you get with a
> murmuration or migration flocks . These things are much more
> loosely bound if they're bound at all with the goals in the
> images when you look at the time lapse material. When you look
> at the time lapse material you can see that they're much more
> individually moving then usually would be found In flocking
> behavior. If anything they're much more loosely bound by the
> external circumstances of the edges of the water body or bodies
> . But the movement seems to be slightly circular and that might
> be the result of flight patterns that are necessary to catch the
> air and move properly in relationship to the other birds to the
> neighbors but it might also be almost random and simply based on
> avoidive behavior and looking for geodesics not quite stop that.
> [that is, aggregative behavior within circumstances dictated by
> neighborhood features such as trees, pools, rivers.] Not looking
> for geodesics but as if they were following highly localized
> coordinates of some sort. I'm dictating this, which is another
> sort of flock behavior in the sense that the words are being put
> together with some kind of semantic continuity that the machine
> is interpreting. But at the same time there are withdrawals and
> things are much looser then that. In this sense the text itself
> is a kind of aggregate that veers off in one way or another.
> What was most amazing was when all of the all of the gulls took
> off simultaneously or roughly simultaneously not in a wave not
> even in a loose flock but from the bridge to the place where I
> was making the recording. More than that, there's a series of
> bridges and a farther bridge which is difficult to see in the
> video they also took off at the same time there must have been
> at least 1000 birds in the river between the two bridges and to
> further bridges that were even beyond those two. I'm fascinated
> by this and have spent a considerable amount of time trying to
> figure out what's going on. Ironically it's a lot easier, easier
> to figure out with the murmuration or sandhill cranes for
> example or migration in V shape patterns in general . But this
> seems different seems a different kind of behavior and the
> disorderliness may in fact be incredibly deep which would be
> really fascinating . Patsy disorderly oneness might in fact be
> incredibly deep . That is disorderliness might in fact be
> incredibly deep. It's the same with this as it is with the
> flight of these birds errors appearing everywhere in the text
> the text bearing off and then coming back just as the birds will
> land somewhat in the same places that they took off from
> somewhat in the same area at least but individually it becomes a
> real headache to try to I sect what's actually going on period
> to try to sense what's actually going on.
> ____
> _______________________________________________
> NetBehaviour mailing list
> NetBehaviour at lists.netbehaviour.org
> https://lists.netbehaviour.org/mailman/listinfo/netbehaviour

-----   |(*,+,#,=)(#,=,*,+)(=,#,+,*)(+,*,=,#)|   ---
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.netbehaviour.org/pipermail/netbehaviour/attachments/20230506/c275f61b/attachment.htm>

More information about the NetBehaviour mailing list