bevy/examples/3d/parenting.rs
Mark Schmale 1ba7429371 Doc/module style doc blocks for examples (#4438)
# Objective

Provide a starting point for #3951, or a partial solution. 
Providing a few comment blocks to discuss, and hopefully find better one in the process. 

## Solution

Since I am pretty new to pretty much anything in this context, I figured I'd just start with a draft for some file level doc blocks. For some of them I found more relevant details (or at least things I considered interessting), for some others there is less. 

## Changelog

- Moved some existing comments from main() functions in the 2d examples to the file header level
- Wrote some more comment blocks for most other 2d examples

TODO: 
- [x] 2d/sprite_sheet, wasnt able to come up with something good yet 
- [x] all other example groups...


Also: Please let me know if the commit style is okay, or to verbose. I could certainly squash these things, or add more details if needed. 
I also hope its okay to raise this PR this early, with just a few files changed. Took me long enough and I dont wanted to let it go to waste because I lost motivation to do the whole thing. Additionally I am somewhat uncertain over the style and contents of the commets. So let me know what you thing please.
2022-05-16 13:53:20 +00:00

67 lines
2.0 KiB
Rust

//! Illustrates how to create parent-child relationships between entities and how parent transforms
//! are propagated to their descendants.
use bevy::prelude::*;
fn main() {
App::new()
.insert_resource(Msaa { samples: 4 })
.add_plugins(DefaultPlugins)
.add_startup_system(setup)
.add_system(rotator_system)
.run();
}
/// this component indicates what entities should rotate
#[derive(Component)]
struct Rotator;
/// rotates the parent, which will result in the child also rotating
fn rotator_system(time: Res<Time>, mut query: Query<&mut Transform, With<Rotator>>) {
for mut transform in query.iter_mut() {
transform.rotation *= Quat::from_rotation_x(3.0 * time.delta_seconds());
}
}
/// set up a simple scene with a "parent" cube and a "child" cube
fn setup(
mut commands: Commands,
mut meshes: ResMut<Assets<Mesh>>,
mut materials: ResMut<Assets<StandardMaterial>>,
) {
let cube_handle = meshes.add(Mesh::from(shape::Cube { size: 2.0 }));
let cube_material_handle = materials.add(StandardMaterial {
base_color: Color::rgb(0.8, 0.7, 0.6),
..default()
});
// parent cube
commands
.spawn_bundle(PbrBundle {
mesh: cube_handle.clone(),
material: cube_material_handle.clone(),
transform: Transform::from_xyz(0.0, 0.0, 1.0),
..default()
})
.insert(Rotator)
.with_children(|parent| {
// child cube
parent.spawn_bundle(PbrBundle {
mesh: cube_handle,
material: cube_material_handle,
transform: Transform::from_xyz(0.0, 0.0, 3.0),
..default()
});
});
// light
commands.spawn_bundle(PointLightBundle {
transform: Transform::from_xyz(4.0, 5.0, -4.0),
..default()
});
// camera
commands.spawn_bundle(PerspectiveCameraBundle {
transform: Transform::from_xyz(5.0, 10.0, 10.0).looking_at(Vec3::ZERO, Vec3::Y),
..default()
});
}