Interactions.jl — A Physics Engine for Julia Games

Julia is a high-performance programming language designed for simulation, visualization, and scientific computing — all essential in game physics.
Interactions.jl is a lightweight 2D/3D physics engine written in Julia, built with game development in mind.

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Installation

julia> ]add Interactions

And for the development version

julia> ]add https://github.com/Gesee-y/Interactions.jl

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Features

• Mass-Aggregate Simulation: Simulate individual or grouped particles.

• Forces System: Built-in forces like SpringForce, BuoyancyForce, and a simple interface to define your own.

• Dynamic Constraints: Connect objects using constraints — joints, limits, and more — or define custom ones.

• Collision Detection:

  • 2D: Fast grid-based detection using bitboards (O(n) in practice).
  • 3D: Uses spatial partitioning structures.

• Verlet Integration: Stable and efficient physics integration method.

• Rigid and Static Bodies: Supports both dynamic and immobile objects.

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Example

using Interactions

# Particle2D(inverse_mass, position, velocity, acceleration, force_accumulation, damping)
p = Particle2D(0.005, Vec2f(1.5, 0), Vec2f(-30, 40), Vec2f(20, 0), Vec2f(0, 0), 0.99)

# Update particle position over time
integrate!(p, Δ)

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License

This package is licensed under the MIT License.

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Bug Reports

If you encounter a bug or numerical issue, feel free to open an issue on GitHub — your feedback helps improve the engine.