bevy_eulerian_fluid

This project is a fluid simulation plugin for Bevy.

Try it on here!

Basic Usage

1. Add FluidPlugin to the app.
2. Spawn FluidSettings, then FluidSimulationBundle will be inserted automatically to the entity. By querying components bundled with FluidSimulationBundle such as VelocityTextures, the simulation results can be retreived.

Here is a short example. See examples for the detailed implementation!

use bevy_eulerian_fluid::{
    definition::{FluidSettings, LevelsetTextures, VelocityTextures},
    FluidPlugin,
};

fn main() {
    App::new()
        .add_plugins(DefaultPlugins)
        .add_plugins(FluidPlugin)
        .add_systems(Startup, setup_scene)
        .add_systems(Update, on_initialized)
        .run();
}

fn setup_scene(mut commands: Commands) {
    commands.spawn(Camera2dBundle::default());

    commands.spawn(FluidSettings {
        dx: 1.0f32,
        dt: 0.5f32,
        rho: 997f32, // water
        gravity: Vec2::Y,
        size: (512, 512),
        initial_fluid_level: 0.9,
    });
}

fn on_initialized(
    mut commands: Commands,
    query: Query<(Entity, &LevelsetTextures, &VelocityTextures), Added<LevelsetTextures>>,
    mut meshes: ResMut<Assets<Mesh>>,
    mut materials: ResMut<Assets<CustomMaterial>>,
    mut velocity_materials: ResMut<Assets<VelocityMaterial>>,
) {
    for (entity, levelset_textures, velocity_textures) in &query {
        // Implement your own code to visualize the results.
    }
}

Interact to the fluid

The simulation entity has LocalForces component, which holds arrays of forces (in m/s^2) and position (in pixels). forces can be applied to the simulation domain by setting LocalForces.

See also an interaction example for the detailed implementation.

Features

• Incompressible 2D fluid simulation
• Viscosity
• Fluid surface
  • Basic implementation
  • Fluid source/drain
• Solid body interaction
  • One-way solid body to fluid interaction
  • Two-way coupling with solid body and fluid
  • Various shapes support
    • Circle

Examples

There are some examples to demonstrate how to visualize and interact to the simulation results:

• Imposing forces with mouse and touch input (Also available here)

  cargo run --example interaction
  

  

• Solid-to-fluid feedback

  cargo run --example demo
  

  

• Spawn multiple fluids

  cargo run --example multiple
  

  

• Fluid surface

  cargo run --example water_surface
  

  

Acknowledgments

The simulation is inspired by and based on the algorithms described in these books:

• Fluid Simulation for Computer Graphics by Robert Bridson
• GPU Gems Chapter 38 by Mark J. Harris

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.