The Hungry Piranha Project

1
The Hungry Piranha Project

• Ruth Ablett
• Ania Barbasiewicz
• Karel Bergmann
• Kevin Meyer
• Carmen Simpson

2
Topics to be Discussed

• Overview
• Swarming Behaviours
• Implementation Notes
• Piranha Life Cycle
• Other Agents
• Agent Interactions
• All Together
• Member Duties

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Overview What did we do?

• 3D Swarm simulation
• Interacting agents
• Piranhas eating cows
• Aging
• Fitness
• Reproduction

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Overview - Inspiration

• Red Piranha (Pygocentrus cariba)
• Lives in large schools
• Highly aggressive feeding habits
• Feeding Video

5
Swarming Behaviours

• Natural Pretext
• Boids Algorithm
• Collision Avoidance
• Velocity Matching
• Flock Centering
• Mathematical Distillations

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Swarming Natural Pretext

• Swarms seen commonly in nature
• Birds (flocks)
• Fish (schools)
• Insect (swarms)

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Swarming Boids

• Reynolds, C. W. (1987)
• Flocks, Herds, and Schools A Distributed
  Behavioral Model
• Computer Graphics, 21(4)
• (SIGGRAPH '87 Conference Proceedings)
• pages 25-34.
• Collision Avoidance
• Velocity Matching
• Flock Centering

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Swarming - Boids
Swarming Piranha Video Clip
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Swarming BoidsCollision Avoidance

• Avoid collisions with flock mates
• Steer away from average position of neighbours
• Conflicts with cohesion of flock

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Swarming BoidsVelocity Matching

• Match velocity of local flock mates
• Collaborative with flock centering
• Ensures cohesion of flock

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Swarming BoidsFlock Centering

• Steer towards average position of flock mates
• Conflicts with Collision Avoidance
• Regulates flock density

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SwarmingMathematical Distillations

• Operating within R3, Which is a Vector Space

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SwarmingMathematical Distillations

• Simplification of swarming
• Velocity and Acceleration under Breve
• Can be simplified to a single direction vector
• Velocity vector magnitude
• Acceleration rate of change of vector magnitude

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Swarming Mathematical Distillations

• Collision Avoidance
• Velocity Matching
• Flock Centering

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SwarmingMathematical Distillations

• All Together
• For weight factors a,b,c

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Implementation Notes

• Boids
• Breve
• Mac, Windows, Linux Platforms
• Neighbour detection
• Neighbour identification

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Implementation NotesSimulation Short-falls

• Breve
• Performance with many agents
• Image loading problems
• Heavy video requirements
• Overall stability

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Piranha Life Cycle

• Piranhas
• Gain fitness after eating
• Lose fitness after breeding
• Reproduce
• Die of starvation

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Other Agents

• Cows
• Randomly introduced
• Stationary
• Junk Food
• Randomly introduced
• Mobile
• Blood
• Mobile
• Introduced after feeding

20
Agent Interactions

• Piranhas school with each other
• Reproductive piranhas breed with other
  reproductive piranhas
• Fry are spawned after a mating
• Piranhas eat cows
• Piranhas ignore junk food
• Piranhas ignore blood

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Agent InteractionsImplementation

• Behaviour switching algorithm
• Schooling, Breeding, Eating
• Agent interaction video clip

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All Together
23
All Together

• Video Clip

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Member Duties

• Programming Ania, Carmen, Kevin, Karel
• Algorithm Design Karel
• Presentations Karel, Ruth
• Webpage Ruth
• Report/Research Everybody

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Summary

• Project exceeded requirements in proposal
• Complex swarms can be built with minimal
  individual complexity
• Questions?