Cbirds: A flock of birds in your terminal | Hacker News Reader

Cbirds: A flock of birds in your terminal

github.com

43 pointsepestr25 comments

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Made a web version: https://nicobrenner.github.io/flock/

Hi, you even ported the hawks and the flocks function. Thanks for the credit!

For sure, that was fun. Thank you for making cbirds, awesome project!

Someone should make this but with a flock of seagulls running so far away. Night and day of course.

Is it as fun as xroach?

I've never played xroach, but you can make the birds escape by pointing at the flock with the cursor

The roaches would run out from under a moved window and you could squash them. I found it hilarious

Not to be confused with the Ascention Flock of Birds 6-DOF tracking device, like the Polhemus Fastrack, SpaceBall, or SpaceMouse.

https://news.ycombinator.com/item?id=22788773

>Body Electric supported all kinds of interesting input and output devices, including MIDI, sending and receiving UDP packets over Ethernet, loading Swivel3D 3D skeleton files and animating them, sending their state over the network to a pair of SGI workstations for rendering with the Isaac rendering engine to the VPL "EyePhones" VR headset (one SGI workstation per eye, with a Mac to run the simulation), VR input devices like VPL's DataGlove and Body Suit, 3D input devices like the Ascension Flock of Birds, Polhemus, and Spaceball, 3D audio output devices like the Convolvotron, and lots of other cool stuff.

https://www.jamodrum.net/Articles/jaron.pdf

>Ascension Bird. Perched atop Lanier's head is Ascension Bird, a 6-axis magnetic tracking device that Lanier connects to SGI Maximum Impact and Octane workstations. This unit is similar to a Polhemus device used for motion cарture and 3-D digitization in VR worlds, but it is slightly more stable in performance. (Lanier's system also includes a series of Macintosh computers that connect to the sensors via an Opcode Studio 5 MIDI interface/patch bay/processor.) Ascension Bird works in a multiunit configuration called Flock of Birds. Used with a series of transmitters and receivers and VPL's Body Electric software, this system creates 3-dimensional virtual environments where objects can be linked and rendered in real time. For example, Lanier's face is glommed onto a slithering insectlike creature reminiscent of Alice in Wonderland. (Body Electric is a MAХ like programming environment specialized for virtual reality applications. At present it is not commercially available, but it may be available soon for noncommercial academic distribution.) Sensitive to the slightest movement, Ascension Bird has a life of its own and slides across Lanier's face, projecting its travels up and down its circuitous route onto the entomological image.

Ascension Technology Flock of Birds Quick Start

https://www.youtube.com/watch?v=6KSaBDvkHBQ

https://fob.sourceforge.net/clemson.html

http://www.mindflux.com.au/products/ascension/fob.html

https://wiki.ros.org/asr_flock_of_birds

https://www.diva-portal.org/smash/get/diva2:19610/FULLTEXT01...

https://my.eng.utah.edu/~cs6360/Assignments/Ascension.html

I wonder what is the value of such vibe coded programs. It can't be the implementation or engineering aspect at all, when generated by AI. Is it the idea? Should it be a tribute to Craig Reynolds in this case?

I guess all these programs are just ideas now, instead of a feat of engineering?

So more like a comment or idea shared at a social gathering, that anyone else might build on with their own in conversation. rather than the prior situation of code, where it is as if we were in wonder at the very fact of speech itself

At least that's my optimistic take. Though many might find the same thing a bummer.

There will still be poets, and those who admire them

> I wonder what is the value of such vibe coded programs.

It took weeks for me to code programs with no real value.

I think it's great that anyone with enough ambition can create software now.

Edit: I forked it and added a flake.nix just to see it in action and its awesome.

Thanks, glad you like it!

> I think it's great that anyone with enough ambition can create software now.

They always could. How do you think I learned to do it?

The first commits are from September 2025, when agents were far less capable than now. Later I decided to use AI to implement some features.

As for the value: exploring ideas, techniques and features that would have been impossible to explore completely by hand (if you have a life), and a final artifact that is cool and pleasant to watch in your terminal.

Craig Reynolds worked for an AI company named Symbolics, for Christ's sake! ;)

So what was the value in 1986 of having a Symbolics Lisp Machine calculate the flocking behavior and render the graphics instead of working out all the animation with a slide rule and graph paper then drawing each frame by hand?

Cheating by using a powerful AI programming language like Lisp and expensive Lisp Machine hardware and Genera AI programming environment to automatically perform all the hard work sucked all the fun and artistic expression and human touch out of it. Think of how many pencil pushing number crunchers and pen and ink animators Boids have put out of work! /s

If you're going to be an anti-AI luddite, then be consistent and go all the way.

No doubt inspired by the recent sonnet 5.5 release demoing a murmuration of birds

Hi, I'm the creator. Not at all: I started this project completely by hand about a year ago, the first commit is from September 2025, you can check. Then I chose to speed up some features with automatic programming, otherwise I wouldn't have had the time

It runs since like 30 minutes in fullscreen in ghostty on my 4k display and I love it.

Thanks, I have a local branch where I'm working on a 3D version with a single flock, it should land in a few days

In a few days? How far are these birds flying? :D

They landed two hours before your comment: cbirds --3d in 1.7.0

Interested to hear about your agent setup for this. Which seems rather successful from the look of the project. Esp since you started by hand.

It goes back a lot further than that:

Craig Reynolds - Original 1986 Boids simulation

https://www.youtube.com/watch?v=86iQiV3-3IA

1987 Stanley and Stella Breaking the Ice (Remastered) by Tom McMahon Michael Wahrman Craig Reynolds

https://www.youtube.com/watch?v=K2ZZKEGlOks

Craig Reynolds #SCCS2015

https://www.youtube.com/watch?v=rqP_c5zm89Q

>Pioneer Craig Reynolds shares his groundbreaking work in artificial life and computer animation. Reynolds describes his lifelong fascination with simulating natural complexity computationally. By modeling flocking birds from the bottom up, based on simple rules for how individual birds move, Reynolds made the astonishing flock emerge. This agent-based approach allowed new insights into collective behavior impossible to gather from nature alone. Reynolds reflects on the significance of his iconic 1987 "Boids" model for animating birds in films like Batman Returns. But its influence extends further - to complexity science and understanding real-world systems like traffic flow and crowd dynamics. According to Reynolds, the beauty of simple models is their emergent properties. By distilling phenomena to basic rules, computer simulation uncovers new truths about the world. Join this fascinating conversation with a legend of artificial life and computer graphics.

Boids: Background and Update, by Craig Reynolds

https://www.red3d.com/cwr/boids/

Blender Tutorial - Full Guide to Boid Particles

https://www.youtube.com/watch?v=J3TUPYVsxow

https://news.ycombinator.com/item?id=22710201

>I've confirmed with Craig Reynolds that yes indeed, then name of Boids was inspired by The Producers:

https://www.youtube.com/watch?v=aL6mTMShVyk

>"He's up on the roof with his boids. He keeps boids. Doity, disgusting, filthy, lice ridden boids." -The Concierge, not a Madam

Thanks, I appreciated your analysis. By the way, Reynolds has been credited in the README since its first version. I first heard of his boids in an introductory AI course (multi-agent systems, search algorithms, adversarial search, CSP, planning, etc.) and I was immediately fascinated by the algorithm

Craig also developed OpenSteer in 2002:

OpenSteer: Steering Behaviors for Autonomous Characters

https://github.com/meshula/OpenSteer

>OpenSteer is a C++ library for constructing steering behaviors for autonomous characters in games and animation. In addition to the library, OpenSteer provides an OpenGL-based application called OpenSteerDemo which demonstrates a variety of steering behaviors. The user can quickly prototype, visualize, annotate and debug new steering behaviors by writing a plug-in for OpenSteerDemo. [...]

>OpenSteer was initially developed by Craig Reynolds beginning in 2002 at the Research and Development group of Sony Computer Entertainment America. The OpenSteer authors wish to acknowledge the support of SCEA, SCEI and in particular these executives who had the foresight to release this code as open source for all to use: Shin'ichi Okamoto, Masa Chatani and Dominic Mallinson.

Also there's Blender's boids system, which has two main ancestors: Craig Reynolds' behavioral animation research, and Janne Karhu's rewrite of Blender's particle system. Its evolution turned the classic flocking model into an animator-controlled toolkit for flocks, herds, pursuit, and simple battles.

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