Primordial Particle System

A high-performance C++ simulation of emergent life — over 1,000,000 particles, 3 rules.

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What is the Primordial Particle System?

The Primordial Particle System is a zero-intelligence particle model originally designed by the Artificial Life Lab Graz. Each particle follows three local rules based on its immediate neighbours. Together they produce complex lifelike behaviour: swarming, clustering, rotating rings, and chain-like structures that emerge from chaos.

No global Update rules, Every particle acts independently based on local information.

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Showcase

Reproduction	Survival	Death
Self-Replicating	Self-Sustaining	1M+ particles, real-time
moving as one body	with no central logic	running on a single machine

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Features

• 1,000,000+ particles running in real-time (10,000,000 at 10fps)
• Multithreaded update loop with a custom thread pool
• Spatial hash grid for O(1) average-case neighbour lookup
• Live parameter tuning — adjust α, β, and speed mid-simulation
• Colourised by local density — sparse particles are dim, dense clusters glow
• SFML rendering with batched draw calls for minimal GPU overhead
• Configurable via TOML — no recompiling to tweak settings

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The Rules

Each particle has a position and a heading angle φ. Every tick:

N  = number of neighbours within radius r
R  = neighbours to the right
L  = neighbours to the left

φ  +=  α  +  β × N × sign(R - L)

α and β are the only two parameters. Everything you see in the simulation is a result of these four lines.

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Performance Benchmarking

Particle Count	Resolution	FPS (avg)	Hardware
100,000	1920×1080	~60	i5 / GTX 1060
500,000	1920×1080	~70	i7 / RTX 4080
1,000,000+	1920×1080	~90	i9 / RTX 5060

Key optimisations:

• Spatial hashing replaces O(n²) neighbour search with near-O(1) grid lookups
• Half-grid traversal eliminates redundant symmetric pair checks
• Thread pool distributes particle updates across all available cores
• Batched SFML rendering — all particles drawn in a single VertexArray pass

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Getting Started

Prerequisites

• C++17 compiler (MSVC, GCC, or Clang)
• CMake 3.16+
• SFML 2.6
• toml++ (included as a header)

Building on Windows

git clone https://github.com/curtis-aln/Primordial-Particle-System.git
cd Primordial-Particle-System
cmake -S . -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build --config Release

Building on Linux

sudo apt install libsfml-dev
git clone https://github.com/curtis-aln/Primordial-Particle-System.git
cd Primordial-Particle-System
cmake -S . -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build

Note: SFML must be installed and findable by CMake. On Windows, set SFML_DIR in your CMake config to the SFML install path if it isn't auto-detected.

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Controls

Key / Input	Action
Space	Pause / Resume
R	Reset simulation
Scroll	Zoom in / out
Middle Mouse	Pan camera
+ / -	Increase / decrease particle count
F	Toggle FPS display

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Configuration

Settings are loaded from settings.toml in the project root. Key parameters:

[simulation]
particle_count = 100000
radius         = 5.0
alpha          = 180.0   # degrees
beta           = 17.0    # degrees
speed          = 0.67

[rendering]
window_width   = 1920
window_height  = 1080
target_fps     = 60

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Acknowledgements

• Primordial Particle System — original model by Artificial Life Lab Graz
• Paper: "How a life-like system emerges from a simple particle motion law" — Schmickl et al.
• Built with SFML and toml++

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License

Distributed under the MIT License. See LICENSE for details.

_{Built by curtis-aln}