bevy_lit

bevy_lit is a simple and easy-to-use 2D lighting library for Bevy, designed to work seamlessly with a single camera setup. The library provides basic lighting functionalities through the types: Lighting2dSettings, AmbientLight2d, LightOccluder2d, and PointLight2d.

Features

• Lighting2dSettings: Controls lighting parameters such as shadow softness
• AmbientLight2d: Provides a general light source that illuminates the entire scene uniformly.
• PointLight2d: Emits light from a specific point, simulating light sources like lamps or torches.
• LightOccluder2d: Creates shadows and blocks light from PointLight2d.
• Web support both for WebGPU and WebGL2 targets

Getting Started

Installation

You can add bevy_lit to your Cargo.lock:

[dependencies]
bevy_lit = "0.2"

Or install it using the CLI:

cargo add bevy_lit

Demo

cargo run --example basic

Usage

Below is a basic example demonstrating how to set up and use bevy_lit in your Bevy project:

use bevy::prelude::*;
use bevy_lit::prelude::*;

fn main() {
    App::new()
        .add_plugins((DefaultPlugins, Lighting2dPlugin))
        .add_systems(Startup, setup)
        .run();
}

fn setup(mut commands: Commands) {
    commands.spawn((
        Camera2dBundle::default(),
        Lighting2dSettings {
            shadow_softness: 32.0,
            ..default()
        },
        AmbientLight2d {
            brightness: 0.2,
            color: Color::Srgba(Srgba::hex("#C09AFE").unwrap()),
        },
    ));

    commands.spawn(PointLight2dBundle {
        point_light: PointLight2d {
            color: Color::rgb(1.0, 1.0, 1.0),
            intensity: 3.0,
            radius: 200.0,
            falloff: 2.0,
        },
        ..default()
    });

    commands.spawn(LightOccluder2dBundle {
        light_occluder: LightOccluder2d::new(Vec2::new(50.0, 50.0)),
        transform: Transform::from_xyz(0.0, 200.0, 0.0),
        ..default()
    });
}

Implementation

bevy_lit uses signed distance fields (SDFs) to compute the occluders' distances. To soften the shadows, a blur is applied. This approach is not ideal and might have limitations in terms of performance and visual accuracy, but it provides a starting point for basic 2D lighting effects.

Acknowledgement

This library took heavy inspiration from the work of other developers. I learned a lot about lighting and Bevy development by reading the source code of the following crates:

• bevy_light_2d
• bevy-magic-light-2d

Contributing

Contributions are welcome! Please open an issue or submit a pull request.

License

bevy_lit is licensed under the MIT License. See LICENSE for more details.