Crate bevy_gym 

Bevy ECS plugin for parallelised RL environment simulation.

bevy-gym bridges rl-traits environments into Bevy’s ECS, giving you:

• Free parallelism: N environment instances as separate Bevy entities, stepped in parallel via par_iter_mut() each FixedUpdate tick.

• Decoupled tick rate: RL simulation runs in FixedUpdate at a configurable Hz. Rendering (if enabled) runs in Update at frame rate. The two are completely independent.

• Headless training mode: disable rendering entirely and run at maximum CPU throughput via ScheduleRunnerPlugin.

• Event-driven policy integration: ActionRequestEvent tells your policy system when to provide the next action. ExperienceEvent delivers the full (s, a, r, s', status) transition back to ember-rl (or any other consumer) without coupling to Bevy internals.

Quick start

use bevy::prelude::*;
use bevy_gym::{BevyGymPlugin, ActionRequestEvent, ExperienceEvent};
use bevy_gym::components::{CurrentObservation, PendingAction};

// Headless training with 16 parallel environments
App::new()
    .add_plugins(MinimalPlugins)
    .add_plugins(
        BevyGymPlugin::new(|i| CartPoleEnv::new(i as u64), 16)
            .headless()
    )
    .add_systems(FixedUpdate, random_policy_system)
    .run();

// Random policy: write a random action whenever one is requested
fn random_policy_system(
    mut requests: EventReader<ActionRequestEvent>,
    mut query: Query<(&EnvId, &mut PendingAction<CartPoleEnv>)>,
) {
    for req in requests.read() {
        if let Some((_, mut pending)) = query.iter_mut()
            .find(|(id, _)| id.0 == req.env_id)
        {
            pending.action = Some(rand::random::<usize>() % 2);
        }
    }
}

Re-exports

pub use components::CurrentObservation;

pub use components::EnvId;

pub use components::EnvStats;

pub use components::EnvironmentComponent;

pub use components::PendingAction;

pub use events::ActionRequestEvent;

pub use events::EpisodeEndEvent;

pub use events::ExperienceEvent;

pub use plugin::spawn_environments;

pub use plugin::BevyGymPlugin;

pub use plugin::GymConfig;

pub use plugin::GymSet;

pub use systems::reset::ResetRequested;

Modules

components

events

plugin

systems