c6958b3056
# 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>
74 lines
2.4 KiB
Rust
74 lines
2.4 KiB
Rust
//! Update a scene from a glTF file, either by spawning the scene as a child of another entity,
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//! or by accessing the entities of the scene.
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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_startup_system(setup)
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.add_system(move_scene_entities)
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.run();
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}
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#[derive(Component)]
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struct MovedScene;
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fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
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commands.spawn_bundle(PointLightBundle {
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transform: Transform::from_xyz(4.0, 5.0, 4.0),
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..default()
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});
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commands.spawn_bundle(Camera3dBundle {
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transform: Transform::from_xyz(1.05, 0.9, 1.5)
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.looking_at(Vec3::new(0.0, 0.3, 0.0), Vec3::Y),
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..default()
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});
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// Spawn the scene as a child of this entity at the given transform
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commands.spawn_bundle(SceneBundle {
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transform: Transform::from_xyz(0.0, 0.0, -1.0),
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scene: asset_server.load("models/FlightHelmet/FlightHelmet.gltf#Scene0"),
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..default()
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});
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// Spawn a second scene, and add a tag component to be able to target it later
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commands
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.spawn_bundle(SceneBundle {
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scene: asset_server.load("models/FlightHelmet/FlightHelmet.gltf#Scene0"),
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..default()
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})
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.insert(MovedScene);
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}
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// This system will move all entities that are descendants of MovedScene (which will be all entities spawned in the scene)
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fn move_scene_entities(
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time: Res<Time>,
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moved_scene: Query<Entity, With<MovedScene>>,
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children: Query<&Children>,
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mut transforms: Query<&mut Transform>,
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) {
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for moved_scene_entity in moved_scene.iter() {
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let mut offset = 0.;
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iter_hierarchy(moved_scene_entity, &children, &mut |entity| {
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if let Ok(mut transform) = transforms.get_mut(entity) {
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transform.translation = Vec3::new(
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offset * time.seconds_since_startup().sin() as f32 / 20.,
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0.,
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time.seconds_since_startup().cos() as f32 / 20.,
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);
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offset += 1.0;
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}
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});
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}
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}
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fn iter_hierarchy(entity: Entity, children_query: &Query<&Children>, f: &mut impl FnMut(Entity)) {
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(f)(entity);
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if let Ok(children) = children_query.get(entity) {
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for child in children.iter().copied() {
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iter_hierarchy(child, children_query, f);
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}
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}
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}
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