atmospheric_fog.rs:
use bevy::{
pbr::{CascadeShadowConfigBuilder, NotShadowCaster},
prelude::*,
};
fn main() {
App::new()
.add_plugins(DefaultPlugins)
.add_systems(
Startup,
(setup_camera_fog, setup_terrain_scene, setup_instructions),
)
.add_systems(Update, toggle_system)
.run();
}
fn setup_camera_fog(mut commands: Commands) {
commands.spawn((
Camera3dBundle {
transform: Transform::from_xyz(-1.0, 0.1, 1.0)
.looking_at(Vec3::new(0.0, 0.0, 0.0), Vec3::Y),
..default()
},
FogSettings {
color: Color::srgba(0.35, 0.48, 0.66, 1.0),
directional_light_color: Color::srgba(1.0, 0.95, 0.85, 0.5),
directional_light_exponent: 30.0,
falloff: FogFalloff::from_visibility_colors(
15.0, Color::srgb(0.35, 0.5, 0.66), Color::srgb(0.8, 0.844, 1.0), ),
},
));
}
fn setup_terrain_scene(
mut commands: Commands,
mut meshes: ResMut<Assets<Mesh>>,
mut materials: ResMut<Assets<StandardMaterial>>,
asset_server: Res<AssetServer>,
) {
let cascade_shadow_config = CascadeShadowConfigBuilder {
first_cascade_far_bound: 0.3,
maximum_distance: 3.0,
..default()
}
.build();
commands.spawn(DirectionalLightBundle {
directional_light: DirectionalLight {
color: Color::srgb(0.98, 0.95, 0.82),
shadows_enabled: true,
..default()
},
transform: Transform::from_xyz(0.0, 0.0, 0.0)
.looking_at(Vec3::new(-0.15, -0.05, 0.25), Vec3::Y),
cascade_shadow_config,
..default()
});
commands.spawn(SceneBundle {
scene: asset_server
.load(GltfAssetLabel::Scene(0).from_asset("models/terrain/Mountains.gltf")),
..default()
});
commands.spawn((
PbrBundle {
mesh: meshes.add(Cuboid::new(2.0, 1.0, 1.0)),
material: materials.add(StandardMaterial {
base_color: Srgba::hex("888888").unwrap().into(),
unlit: true,
cull_mode: None,
..default()
}),
transform: Transform::from_scale(Vec3::splat(20.0)),
..default()
},
NotShadowCaster,
));
}
fn setup_instructions(mut commands: Commands) {
commands.spawn(
TextBundle::from_section(
"Press Spacebar to Toggle Atmospheric Fog.\nPress S to Toggle Directional Light Fog Influence.",
TextStyle::default(),
)
.with_style(Style {
position_type: PositionType::Absolute,
bottom: Val::Px(12.0),
left: Val::Px(12.0),
..default()
}),
);
}
fn toggle_system(keycode: Res<ButtonInput<KeyCode>>, mut fog: Query<&mut FogSettings>) {
let mut fog_settings = fog.single_mut();
if keycode.just_pressed(KeyCode::Space) {
let a = fog_settings.color.alpha();
fog_settings.color.set_alpha(1.0 - a);
}
if keycode.just_pressed(KeyCode::KeyS) {
let a = fog_settings.directional_light_color.alpha();
fog_settings.directional_light_color.set_alpha(0.5 - a);
}
}