symtropy-bevy-core

Permissively-licensed Bevy plugin for symtropy-physics N-dimensional physics.

Zero AGPL dependencies. Safe for proprietary projects.

What you get

BevyPhysics<D> — Bevy Resource wrapping a PhysicsWorld<D>.
PhysicsBody — Bevy Component linking an entity to a physics body.
NoCouplingResource — identity-modulation PhysicsCallback for physics-only usage.
BevyPhysicsPlugin<D> — drop-in plugin with NoCoupling step (2D / 3D / 4D).
BevyPhysicsCorePlugin<D> — minimal plugin without a step system (users add their own).
step_physics<D, C> — generic step system for any PhysicsCallback + Resource.
sync_transforms<D> — write physics positions to Bevy Transform.

Quickstart

use bevy::prelude::*;
use symtropy_bevy_core::{BevyPhysicsPlugin, BevyPhysics, PhysicsBody};
use symtropy_physics::body::Point;

fn main() {
    App::new()
        .add_plugins(DefaultPlugins)
        .add_plugins(BevyPhysicsPlugin::<3>::with_gravity([0.0, -9.81, 0.0]))
        .add_systems(Startup, spawn_ball)
        .run();
}

fn spawn_ball(
    mut commands: Commands,
    mut physics: ResMut<BevyPhysics<3>>,
) {
    let handle = physics.world.add_sphere(Point::new([0.0, 10.0, 0.0]), 1.0, 1.0);
    commands.spawn((
        PhysicsBody::new(handle, 1.0),
        Transform::default(),
    ));
}

Bring your own coupling

If you want to couple a custom per-body metric (health, trust, skill, wealth, …) to physics, implement PhysicsCallback<D> on your own Resource type:

use bevy::prelude::*;
use nalgebra::SVector;
use symtropy_physics::{BodyHandle, CollisionEvent, PhysicsCallback};
use symtropy_bevy_core::{BevyPhysicsCorePlugin, step_physics, sync_transforms};
use std::collections::HashMap;

#[derive(Resource, Default)]
struct HealthField(HashMap<BodyHandle, f64>);

impl<const D: usize> PhysicsCallback<D> for HealthField {
    fn modulate_force(&self, body: BodyHandle, force: &SVector<f64, D>) -> SVector<f64, D> {
        let hp = self.0.get(&body).copied().unwrap_or(1.0);
        force * hp  // low HP → weaker motor authority
    }
    fn modulate_impulse(&self, impulse: f64, _: &SVector<f64, D>) -> f64 { impulse }
    fn friction_multiplier(&self, _: &SVector<f64, D>, _: BodyHandle) -> f64 { 1.0 }
    fn on_collision(&mut self, _: &CollisionEvent<D>) {}
    fn record_dissipation(&mut self, _: f64) {}
}

fn main() {
    App::new()
        .add_plugins(DefaultPlugins)
        .add_plugins(BevyPhysicsCorePlugin::<3>::with_gravity([0.0, -9.81, 0.0]))
        .insert_resource(HealthField::default())
        .add_systems(FixedUpdate, (
            step_physics::<3, HealthField>,
            sync_transforms::<3>,
        ).chain())
        .run();
}

For Φ-coupling (IIT research)

Use the AGPL sibling crate symtropy-bevy, which wires ConsciousnessField from symtropy-consciousness-physics. Same plugin API, adds 5-channel Φ coupling, biometrics integration, and macro-world modifiers.

Status