Bevy Simple Water

bevy_simple_water is a small Bevy plugin for adding animated water material to a mesh.

Requirements

The water material shader uses deferred rendering, so your app needs:

.insert_resource(DefaultOpaqueRendererMethod::deferred())

Any camera that should render the water also needs these prepass components:

DeferredPrepass,
DepthPrepass,
MotionVectorPrepass,

Screen-space reflections are optional, but they help if you want stronger reflections. The basic example shows a full scene setup.

Basic use

use bevy::{
    core_pipeline::prepass::{DeferredPrepass, DepthPrepass, MotionVectorPrepass},
    pbr::DefaultOpaqueRendererMethod,
    prelude::*,
};
use bevy_simple_water::{SimpleWaterPlugin, Water};

fn main() {
    App::new()
        .insert_resource(DefaultOpaqueRendererMethod::deferred())
        .add_plugins((DefaultPlugins, SimpleWaterPlugin))
        .add_systems(Startup, setup)
        .run();
}

fn setup(mut commands: Commands, mut meshes: ResMut<Assets<Mesh>>) {
    commands.spawn((
        Water::ocean(),
        Mesh3d(meshes.add(Plane3d::new(Vec3::Y, Vec2::splat(1.0)))),
        Transform::from_scale(Vec3::splat(100.0)),
    ));

    commands.spawn((
        DirectionalLight::default(),
        Transform::from_xyz(1.0, 1.0, 0.0).looking_at(Vec3::ZERO, Vec3::Y),
    ));

    commands.spawn((
        Camera3d::default(),
        Transform::from_xyz(-8.0, 6.0, 0.0).looking_at(Vec3::Y * 1.8, Vec3::Y),
        DeferredPrepass,
        DepthPrepass,
        MotionVectorPrepass,
    ));
}

Presets

The crate includes a few built-in presets:

• Water::ocean()
• Water::tropical()
• Water::lake()
• Water::river()
• Water::pond()
• Water::pool()
• Water::natural_pool()
• Water::swamp()
• Water::arctic()

Water::default() is the same as Water::ocean().

Custom settings

If a preset gets you close, you can start there and override what you need:

Water {
    color: Color::srgb(0.02, 0.10, 0.12),
    perceptual_roughness: 0.05,
    octave_scales: Vec4::new(4.0, 8.0, 16.0, 28.0),
    ..Water::tropical()
}

The Water fields map directly to the shader settings:

• color sets the base color.
• perceptual_roughness controls how sharp or soft reflections look.
• octave_vectors controls wave direction and speed.
• octave_scales controls wave size and frequency.
• octave_strengths controls how strong each octave is.

You can also change a Water component at runtime. The plugin updates the generated material in place.

Examples

Run the example scene:

cargo run --example basic

Run the preset gallery:

cargo run --example presets

The presets example shows every built-in preset side by side and includes a simple free camera.

Run the realtime settings update demo:

cargo run --example realtime_settings

The realtime_settings example mutates Water every frame to show that color and wave settings are applied to the generated material in real time.

Bevy support table

bevy	bevy_simple_water
0.19	0.2
0.18	0.1

Credit

The shader started from Bevy's SSR example and was adapted and expanded from there. The original shader is here:

https://github.com/bevyengine/bevy/blob/v0.18.1/assets/shaders/water_material.wgsl

License

Licensed under either MIT or Apache-2.0, at your option. See LICENSE-MIT and LICENSE-APACHE.