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>
75 lines
2.7 KiB
Rust
75 lines
2.7 KiB
Rust
use bevy_asset::Handle;
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use bevy_derive::{Deref, DerefMut};
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use bevy_ecs::{
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bundle::Bundle,
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change_detection::ResMut,
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entity::Entity,
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prelude::{Changed, Component, Without},
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system::{Commands, Query},
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};
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use bevy_transform::components::{GlobalTransform, Transform};
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use crate::{DynamicScene, InstanceId, Scene, SceneSpawner};
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/// [`InstanceId`] of a spawned scene. It can be used with the [`SceneSpawner`] to
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/// interact with the spawned scene.
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#[derive(Component, Deref, DerefMut)]
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pub struct SceneInstance(InstanceId);
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/// A component bundle for a [`Scene`] root.
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///
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/// The scene from `scene` will be spawn as a child of the entity with this component.
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/// Once it's spawned, the entity will have a [`SceneInstance`] component.
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#[derive(Default, Bundle)]
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pub struct SceneBundle {
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/// Handle to the scene to spawn
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pub scene: Handle<Scene>,
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pub transform: Transform,
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pub global_transform: GlobalTransform,
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}
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/// A component bundle for a [`DynamicScene`] root.
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///
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/// The dynamic scene from `scene` will be spawn as a child of the entity with this component.
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/// Once it's spawned, the entity will have a [`SceneInstance`] component.
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#[derive(Default, Bundle)]
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pub struct DynamicSceneBundle {
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/// Handle to the scene to spawn
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pub scene: Handle<DynamicScene>,
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pub transform: Transform,
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pub global_transform: GlobalTransform,
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}
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/// System that will spawn scenes from [`SceneBundle`].
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pub fn scene_spawner(
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mut commands: Commands,
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mut scene_to_spawn: Query<
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(Entity, &Handle<Scene>, Option<&mut SceneInstance>),
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(Changed<Handle<Scene>>, Without<Handle<DynamicScene>>),
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>,
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mut dynamic_scene_to_spawn: Query<
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(Entity, &Handle<DynamicScene>, Option<&mut SceneInstance>),
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(Changed<Handle<DynamicScene>>, Without<Handle<Scene>>),
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>,
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mut scene_spawner: ResMut<SceneSpawner>,
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) {
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for (entity, scene, instance) in scene_to_spawn.iter_mut() {
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let new_instance = scene_spawner.spawn_as_child(scene.clone(), entity);
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if let Some(mut old_instance) = instance {
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scene_spawner.despawn_instance(**old_instance);
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*old_instance = SceneInstance(new_instance);
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} else {
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commands.entity(entity).insert(SceneInstance(new_instance));
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}
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}
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for (entity, dynamic_scene, instance) in dynamic_scene_to_spawn.iter_mut() {
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let new_instance = scene_spawner.spawn_dynamic_as_child(dynamic_scene.clone(), entity);
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if let Some(mut old_instance) = instance {
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scene_spawner.despawn_instance(**old_instance);
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*old_instance = SceneInstance(new_instance);
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} else {
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commands.entity(entity).insert(SceneInstance(new_instance));
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}
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}
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}
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