flock

new flock experiments

This is Yet Another implementation of the boids model of flocking and related group motions. It was meant just to be a workbench for thinking about new approaches to that old idea.

It is written in Python and Open3D. I started to use c++ and OpenGL, then thought better of it. That earlier start, now unused, is in the cpp/ subdirectory.

I am not publicizing this very WIP code, but if you happen upon it and have any interest in using it, feel free to email me.

Run simulation

After installation (below) simply invoke Python on the main file:

python flock.py

You can control the view using Open3D's standard gestures. There are also several single key commands to change modes. One is “h” which prints this mini-help on the shell:

  flock single key commands:
    space: toggle simulation run/pause
    1:     single simulation step, then pause
    c:     toggle camera between static and boid tracking
    s:     select next boid for camera tracking
    a:     toggle drawing of steering annotation
    w:     toggle between sphere wrap-around or avoidance
    e:     toggle erase mode (spacetime boid worms)
    f:     toggle realtime versus fixed time step of 1/60sec
    b:     toggle blend vs hard switch for obstacle avoidance
    o:     cycle through obstacle selections
    h:     print this message
    esc:   exit simulation.

  mouse view controls:
    Left button + drag         : Rotate.
    Ctrl + left button + drag  : Translate.
    Wheel button + drag        : Translate.
    Shift + left button + drag : Roll.
    Wheel                      : Zoom in/out.

  annotation (in camera tracking mode, “c” to toggle):
    red:     separation force.
    green:   alignment force.
    blue:    cohesion force.
    gray:    combined steering force.
    magenta: ray for obstacle avoidance.

Known bugs (as of June 9, 2023)

Lots, since it is so preliminary, but for example:

• Because boids ignore global orientation, they are just as happy to move vertically as horizontally.
• The boid's “bodies” sort of look like they are shaded, but it is just painted on. It ought to be rendered to provide more orientation cueing.

Installation

Clone this repository from GitHub to your local machine.

I have been using Python 3.10.10 with Open3D 0.17.0. I created a new Python enviroment like this:

conda create -n flock_open3d python=3.10
conda activate flock_open3d
pip install open3d

On my laptop (macOS 12.6.4 MacBook Pro M1) the above complained I was missing libomp so I also did:

brew install libomp

(Not sure if this is relevant but I had previously installed recent versions of GLFW and GLEW for the earlier c++/OpenGL branch. I assume Open3D installs what it needs.)