Murmuration of starlings, the type of behaviour that boids was designed to simulate
Source: YouTube

Boids, a shortened version of “bird-oid object”,[1] is a computational model of flocking behaviour proposed by the computer graphics specialist Craig Reynolds in a paper published in 1987, which he first demonstrated in 1986.[2] Reynolds formally defined flocking as “polarised, non-colliding, aggregate motion”, and his fundamental idea was that rather than scripting the behaviour of each bird in a simulated flock – or fish in a shoal, or animal in a herd – their overall behaviour would emerge if every individual followed three simple rules, without anything in overall control:[2]

  • Separation: steer to avoid crowding local flockmates
  • Alignment: steer towards the average heading of local flockmates
  • Cohesion: steer to move towards the average position of local flockmates

Reynolds’ approach was a significant step forward from the traditional techniques previously used in computer animation. The first film created using his new algorithm was Stanley and Stella in: Breaking the Ice (1987), followed by Tim Burton’s film Batman Returns (1992), with computer-generated bat swarms and armies of penguins marching through the streets of Gotham City.[3]

Flocking, or Particle Swarm Optimization as it is now more formally known, has since become an area of study in several fields of research, including statistical physics, control theory and robotics.[4]

References

  1.  
  2.  
  3.  
  4.  

Bibliography

Bajec, Iztok Lebar, and Frank H. Heppner. “Organized Flight in Birds.” Animal Behaviour, vol. 78, no. 4, Oct. 2009, pp. 777–89, https://www.sciencedirect.com/science/article/abs/pii/S0003347209002966?via%3Dihub.
Banks, Alec, et al. “A Review of Particle Swarm Optimization. Part I: Background Development.” Natural Computing, vol. 6, no. 4, July 2007, pp. 467–84, https://doi.org/https://doi.org/10.1007%2Fs11047-007-9049-5.
Ramos, Rita Parada, et al. “Evolving Flocking Behaviour in Embodied Agents Based on Local and Global Application of Reynolds; Rules.” PLoS ONE, vol. 14, no. 10, 2019, https://doi.org/10.1371/journal.pone.0224376.
Reynolds, Craig. Flocks, Herds and Schools: A Distributed Behavioral Model. SIGGRAPH ’87: Proceedings of the 14th Annual Conference on Computer Graphics and Interactive Techniques. no. 4, 1987, pp. 25–34, https://doi.org/https://dl.acm.org/doi/10.1145/37402.37406.

External links