bevy/examples/3d/update_gltf_scene.rs
MinerSebas 59ee512292 Add TransformBundle (#3054)
# Objective

- Bevy currently has no simple way to make an "empty" Entity work correctly in a Hierachy.
  - The current Solution is to insert a Tuple instead: 

```rs
.insert_bundle((Transform::default(), GlobalTransform::default()))
```

## Solution

* Add a `TransformBundle` that combines the Components:

```rs
.insert_bundle(TransformBundle::default())
```

* The code is based on #2331, except for missing the more controversial usage of `TransformBundle` as a Sub-bundle in preexisting Bundles.

Co-authored-by: MinerSebas <66798382+MinerSebas@users.noreply.github.com>
Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2022-02-06 01:07:55 +00:00

90 lines
2.9 KiB
Rust

use bevy::{prelude::*, scene::InstanceId};
fn main() {
App::new()
.insert_resource(Msaa { samples: 4 })
.add_plugins(DefaultPlugins)
.init_resource::<SceneInstance>()
.add_startup_system(setup)
.add_system(scene_update)
.add_system(move_scene_entities)
.run();
}
// Resource to hold the scene `instance_id` until it is loaded
#[derive(Default)]
struct SceneInstance(Option<InstanceId>);
// Component that will be used to tag entities in the scene
#[derive(Component)]
struct EntityInMyScene;
fn setup(
mut commands: Commands,
asset_server: Res<AssetServer>,
mut scene_spawner: ResMut<SceneSpawner>,
mut scene_instance: ResMut<SceneInstance>,
) {
commands.spawn_bundle(PointLightBundle {
transform: Transform::from_xyz(4.0, 5.0, 4.0),
..Default::default()
});
commands.spawn_bundle(PerspectiveCameraBundle {
transform: Transform::from_xyz(1.05, 0.9, 1.5)
.looking_at(Vec3::new(0.0, 0.3, 0.0), Vec3::Y),
..Default::default()
});
// Spawn the scene as a child of another entity. This first scene will be translated backward
// with its parent
commands
.spawn_bundle(TransformBundle::from(Transform::from_xyz(0.0, 0.0, -1.0)))
.with_children(|parent| {
parent.spawn_scene(asset_server.load("models/FlightHelmet/FlightHelmet.gltf#Scene0"));
});
// Spawn a second scene, and keep its `instance_id`
let instance_id =
scene_spawner.spawn(asset_server.load("models/FlightHelmet/FlightHelmet.gltf#Scene0"));
scene_instance.0 = Some(instance_id);
}
// This system will wait for the scene to be ready, and then tag entities from
// the scene with `EntityInMyScene`. All entities from the second scene will be
// tagged
fn scene_update(
mut commands: Commands,
scene_spawner: Res<SceneSpawner>,
scene_instance: Res<SceneInstance>,
mut done: Local<bool>,
) {
if !*done {
if let Some(instance_id) = scene_instance.0 {
if let Some(entity_iter) = scene_spawner.iter_instance_entities(instance_id) {
entity_iter.for_each(|entity| {
commands.entity(entity).insert(EntityInMyScene);
});
*done = true;
}
}
}
}
// This system will move all entities with component `EntityInMyScene`, so all
// entities from the second scene
fn move_scene_entities(
time: Res<Time>,
mut scene_entities: Query<&mut Transform, With<EntityInMyScene>>,
) {
let mut direction = 1.;
let mut scale = 1.;
for mut transform in scene_entities.iter_mut() {
transform.translation = Vec3::new(
scale * direction * time.seconds_since_startup().sin() as f32 / 20.,
0.,
time.seconds_since_startup().cos() as f32 / 20.,
);
direction *= -1.;
scale += 0.5;
}
}