bevy/examples/3d/atmospheric_fog.rs
Joona Aalto 25bfa80e60
Migrate cameras to required components (#15641)
# Objective

Yet another PR for migrating stuff to required components. This time,
cameras!

## Solution

As per the [selected
proposal](https://hackmd.io/tsYID4CGRiWxzsgawzxG_g#Combined-Proposal-1-Selected),
deprecate `Camera2dBundle` and `Camera3dBundle` in favor of `Camera2d`
and `Camera3d`.

Adding a `Camera` without `Camera2d` or `Camera3d` now logs a warning,
as suggested by Cart [on
Discord](https://discord.com/channels/691052431525675048/1264881140007702558/1291506402832945273).
I would personally like cameras to work a bit differently and be split
into a few more components, to avoid some footguns and confusing
semantics, but that is more controversial, and shouldn't block this core
migration.

## Testing

I ran a few 2D and 3D examples, and tried cameras with and without
render graphs.

---

## Migration Guide

`Camera2dBundle` and `Camera3dBundle` have been deprecated in favor of
`Camera2d` and `Camera3d`. Inserting them will now also insert the other
components required by them automatically.
2024-10-05 01:59:52 +00:00

115 lines
3.6 KiB
Rust

//! This example showcases atmospheric fog
//!
//! ## Controls
//!
//! | Key Binding | Action |
//! |:-------------------|:---------------------------------------|
//! | `Spacebar` | Toggle Atmospheric Fog |
//! | `S` | Toggle Directional Light Fog Influence |
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((
Camera3d::default(),
Transform::from_xyz(-1.0, 0.1, 1.0).looking_at(Vec3::new(0.0, 0.0, 0.0), Vec3::Y),
DistanceFog {
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, // distance in world units up to which objects retain visibility (>= 5% contrast)
Color::srgb(0.35, 0.5, 0.66), // atmospheric extinction color (after light is lost due to absorption by atmospheric particles)
Color::srgb(0.8, 0.844, 1.0), // atmospheric inscattering color (light gained due to scattering from the sun)
),
},
));
}
fn setup_terrain_scene(
mut commands: Commands,
mut meshes: ResMut<Assets<Mesh>>,
mut materials: ResMut<Assets<StandardMaterial>>,
asset_server: Res<AssetServer>,
) {
// Configure a properly scaled cascade shadow map for this scene (defaults are too large, mesh units are in km)
let cascade_shadow_config = CascadeShadowConfigBuilder {
first_cascade_far_bound: 0.3,
maximum_distance: 3.0,
..default()
}
.build();
// Sun
commands.spawn((
DirectionalLight {
color: Color::srgb(0.98, 0.95, 0.82),
shadows_enabled: true,
..default()
},
Transform::from_xyz(0.0, 0.0, 0.0).looking_at(Vec3::new(-0.15, -0.05, 0.25), Vec3::Y),
cascade_shadow_config,
));
// Terrain
commands.spawn(SceneRoot(asset_server.load(
GltfAssetLabel::Scene(0).from_asset("models/terrain/Mountains.gltf"),
)));
// Sky
commands.spawn((
Mesh3d(meshes.add(Cuboid::new(2.0, 1.0, 1.0))),
MeshMaterial3d(materials.add(StandardMaterial {
base_color: Srgba::hex("888888").unwrap().into(),
unlit: true,
cull_mode: None,
..default()
})),
Transform::from_scale(Vec3::splat(20.0)),
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 DistanceFog>) {
let mut fog = fog.single_mut();
if keycode.just_pressed(KeyCode::Space) {
let a = fog.color.alpha();
fog.color.set_alpha(1.0 - a);
}
if keycode.just_pressed(KeyCode::KeyS) {
let a = fog.directional_light_color.alpha();
fog.directional_light_color.set_alpha(0.5 - a);
}
}