Fixes #15834 ## Migration Guide The APIs of `Time`, `Timer` and `Stopwatch` have been cleaned up for consistency with each other and the standard library's `Duration` type. The following methods have been renamed: - `Stowatch::paused` -> `Stopwatch::is_paused` - `Time::elapsed_seconds` -> `Time::elasped_secs` (including `_f64` and `_wrapped` variants)
		
			
				
	
	
		
			61 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			Rust
		
	
	
	
	
	
			
		
		
	
	
			61 lines
		
	
	
		
			1.8 KiB
		
	
	
	
		
			Rust
		
	
	
	
	
	
//! Illustrates how to create parent-child relationships between entities and how parent transforms
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//! are propagated to their descendants.
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use bevy::prelude::*;
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fn main() {
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    App::new()
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        .add_plugins(DefaultPlugins)
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        .add_systems(Startup, setup)
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        .add_systems(Update, rotator_system)
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        .run();
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}
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/// this component indicates what entities should rotate
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#[derive(Component)]
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struct Rotator;
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/// rotates the parent, which will result in the child also rotating
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fn rotator_system(time: Res<Time>, mut query: Query<&mut Transform, With<Rotator>>) {
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    for mut transform in &mut query {
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        transform.rotate_x(3.0 * time.delta_secs());
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    }
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}
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/// set up a simple scene with a "parent" cube and a "child" cube
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fn setup(
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    mut commands: Commands,
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    mut meshes: ResMut<Assets<Mesh>>,
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    mut materials: ResMut<Assets<StandardMaterial>>,
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) {
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    let cube_handle = meshes.add(Cuboid::new(2.0, 2.0, 2.0));
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    let cube_material_handle = materials.add(StandardMaterial {
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        base_color: Color::srgb(0.8, 0.7, 0.6),
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        ..default()
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    });
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    // parent cube
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    commands
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        .spawn((
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            Mesh3d(cube_handle.clone()),
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            MeshMaterial3d(cube_material_handle.clone()),
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            Transform::from_xyz(0.0, 0.0, 1.0),
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            Rotator,
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        ))
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        .with_children(|parent| {
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            // child cube
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            parent.spawn((
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                Mesh3d(cube_handle),
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                MeshMaterial3d(cube_material_handle),
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                Transform::from_xyz(0.0, 0.0, 3.0),
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            ));
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        });
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    // light
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    commands.spawn((PointLight::default(), Transform::from_xyz(4.0, 5.0, -4.0)));
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    // camera
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    commands.spawn((
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        Camera3d::default(),
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        Transform::from_xyz(5.0, 10.0, 10.0).looking_at(Vec3::ZERO, Vec3::Y),
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    ));
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}
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