bevy_fast_light: Simple 2D lighting for Bevy focused on performance over features

[leomeinel]

I have been working on a crate that provides simple and customizable 2D lighting for Bevy in the shape of an attached Mesh2d.

If you are interested in how I did this, please take a look. I'm not sure if I will add any other types of lights since that might bloat up the codebase, but I'm very happy if I get feedback or suggestions :)

I also want to thank all bevy contributors for their awesome work and for making this possible. 🥇

About

Simple 2D lighting for Bevy focused on performance over features.

⚠️ | This is still in development and not at all feature complete.

Features

Lights

Purpose	Component	Config
Ambient light	AmbientLight2d	color and intensity
Mesh light	MeshLight2d	color, intensity

Occluders

Purpose	Component
Mesh occluder	MeshOccluder2d

Sprites are rendered above occluders if they are on the same or a higher z-level. Also see Showcase.

Mesh2d

The following Components allow the customization of their shape via attaching a Mesh2d:

• MeshLight2d
• MeshOccluder2d

The Mesh2d is required for the Components to render.

Limitations

• There is currently no shadow casting for light occluders.

Usage

Take a look at /examples to find out how to use this crate.

Showcase

I am using most features in my learning project Slimy Mist and have also successfully implemented a day/night cycle.

This also visualizes how Sprites are rendered above occluders if they are on the same or a higher z-level.

Examples

ambient_light.rs

Scene with a light sky colored AmbientLight2d with a lower intensity, a green Rectangle as background and an amber MeshLight2d.

mesh_light.rs

Scene with a green Rectangle as background and an amber MeshLight2d.

mesh_occluder.rs

Scene with a light sky colored AmbientLight2d with a lower intensity, a green Rectangle as background, an amber MeshLight2d and a MeshOccluder2d.

texture_scale.rs

Scene with a green Rectangle as background and an amber MeshLight2d using a lower texture_scale.

Alternatives

• bevy_firefly
• bevy_2d_screen_space_lightmaps
• bevy_light_2d
• bevy_lit

Resources

Code

• Bevy Example - Custom Post Processing
• Bevy Example - Custom Render Phase

Articles

• hackmd.io - Bevy's Rendering Crates
• hackmd.io - The Abyss
• slembcke.net - 2D Lighting Techniques
• slembcke.net - 2D Lighting with Hard Shadows
• WebGPU Shading Language

[leomeinel]

Update

Updated the description with current README.md content and added features.