bevy/examples/3d/split_screen.rs
François c6958b3056 add a SceneBundle to spawn a scene (#2424)
# Objective

- Spawning a scene is handled as a special case with a command `spawn_scene` that takes an handle but doesn't let you specify anything else. This is the only handle that works that way.
- Workaround for this have been to add the `spawn_scene` on `ChildBuilder` to be able to specify transform of parent, or to make the `SceneSpawner` available to be able to select entities from a scene by their instance id

## Solution

Add a bundle
```rust
pub struct SceneBundle {
    pub scene: Handle<Scene>,
    pub transform: Transform,
    pub global_transform: GlobalTransform,
    pub instance_id: Option<InstanceId>,
}
```

and instead of 
```rust
commands.spawn_scene(asset_server.load("models/FlightHelmet/FlightHelmet.gltf#Scene0"));
```
you can do
```rust
commands.spawn_bundle(SceneBundle {
    scene: asset_server.load("models/FlightHelmet/FlightHelmet.gltf#Scene0"),
    ..Default::default()
});
```

The scene will be spawned as a child of the entity with the `SceneBundle`

~I would like to remove the command `spawn_scene` in favor of this bundle but didn't do it yet to get feedback first~

Co-authored-by: François <8672791+mockersf@users.noreply.github.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2022-06-09 20:34:09 +00:00

112 lines
3.5 KiB
Rust

//! Renders two cameras to the same window to accomplish "split screen".
use bevy::{
core_pipeline::clear_color::ClearColorConfig,
prelude::*,
render::camera::Viewport,
window::{WindowId, WindowResized},
};
fn main() {
App::new()
.add_plugins(DefaultPlugins)
.add_startup_system(setup)
.add_system(set_camera_viewports)
.run();
}
/// set up a simple 3D scene
fn setup(
mut commands: Commands,
asset_server: Res<AssetServer>,
mut meshes: ResMut<Assets<Mesh>>,
mut materials: ResMut<Assets<StandardMaterial>>,
) {
// plane
commands.spawn_bundle(PbrBundle {
mesh: meshes.add(Mesh::from(shape::Plane { size: 100.0 })),
material: materials.add(Color::rgb(0.3, 0.5, 0.3).into()),
..default()
});
commands.spawn_bundle(SceneBundle {
scene: asset_server.load("models/animated/Fox.glb#Scene0"),
..default()
});
// Light
commands.spawn_bundle(DirectionalLightBundle {
transform: Transform::from_rotation(Quat::from_euler(
EulerRot::ZYX,
0.0,
1.0,
-std::f32::consts::FRAC_PI_4,
)),
directional_light: DirectionalLight {
shadows_enabled: true,
..default()
},
..default()
});
// Left Camera
commands
.spawn_bundle(Camera3dBundle {
transform: Transform::from_xyz(0.0, 200.0, -100.0).looking_at(Vec3::ZERO, Vec3::Y),
..default()
})
.insert(LeftCamera);
// Right Camera
commands
.spawn_bundle(Camera3dBundle {
transform: Transform::from_xyz(100.0, 100., 150.0).looking_at(Vec3::ZERO, Vec3::Y),
camera: Camera {
// Renders the right camera after the left camera, which has a default priority of 0
priority: 1,
..default()
},
camera_3d: Camera3d {
// dont clear on the second camera because the first camera already cleared the window
clear_color: ClearColorConfig::None,
..default()
},
..default()
})
.insert(RightCamera);
}
#[derive(Component)]
struct LeftCamera;
#[derive(Component)]
struct RightCamera;
fn set_camera_viewports(
windows: Res<Windows>,
mut resize_events: EventReader<WindowResized>,
mut left_camera: Query<&mut Camera, (With<LeftCamera>, Without<RightCamera>)>,
mut right_camera: Query<&mut Camera, With<RightCamera>>,
) {
// We need to dynamically resize the camera's viewports whenever the window size changes
// so then each camera always takes up half the screen.
// A resize_event is sent when the window is first created, allowing us to reuse this system for initial setup.
for resize_event in resize_events.iter() {
if resize_event.id == WindowId::primary() {
let window = windows.primary();
let mut left_camera = left_camera.single_mut();
left_camera.viewport = Some(Viewport {
physical_position: UVec2::new(0, 0),
physical_size: UVec2::new(window.physical_width() / 2, window.physical_height()),
..default()
});
let mut right_camera = right_camera.single_mut();
right_camera.viewport = Some(Viewport {
physical_position: UVec2::new(window.physical_width() / 2, 0),
physical_size: UVec2::new(window.physical_width() / 2, window.physical_height()),
..default()
});
}
}
}