# Objective NOTE: This depends on #7267 and should not be merged until #7267 is merged. If you are reviewing this before that is merged, I highly recommend viewing the Base Sets commit instead of trying to find my changes amongst those from #7267. "Default sets" as described by the [Stageless RFC](https://github.com/bevyengine/rfcs/pull/45) have some [unfortunate consequences](https://github.com/bevyengine/bevy/discussions/7365). ## Solution This adds "base sets" as a variant of `SystemSet`: A set is a "base set" if `SystemSet::is_base` returns `true`. Typically this will be opted-in to using the `SystemSet` derive: ```rust #[derive(SystemSet, Clone, Hash, Debug, PartialEq, Eq)] #[system_set(base)] enum MyBaseSet { A, B, } ``` **Base sets are exclusive**: a system can belong to at most one "base set". Adding a system to more than one will result in an error. When possible we fail immediately during system-config-time with a nice file + line number. For the more nested graph-ey cases, this will fail at the final schedule build. **Base sets cannot belong to other sets**: this is where the word "base" comes from Systems and Sets can only be added to base sets using `in_base_set`. Calling `in_set` with a base set will fail. As will calling `in_base_set` with a normal set. ```rust app.add_system(foo.in_base_set(MyBaseSet::A)) // X must be a normal set ... base sets cannot be added to base sets .configure_set(X.in_base_set(MyBaseSet::A)) ``` Base sets can still be configured like normal sets: ```rust app.add_system(MyBaseSet::B.after(MyBaseSet::Ap)) ``` The primary use case for base sets is enabling a "default base set": ```rust schedule.set_default_base_set(CoreSet::Update) // this will belong to CoreSet::Update by default .add_system(foo) // this will override the default base set with PostUpdate .add_system(bar.in_base_set(CoreSet::PostUpdate)) ``` This allows us to build apis that work by default in the standard Bevy style. This is a rough analog to the "default stage" model, but it use the new "stageless sets" model instead, with all of the ordering flexibility (including exclusive systems) that it provides. --- ## Changelog - Added "base sets" and ported CoreSet to use them. ## Migration Guide TODO
		
			
				
	
	
		
			73 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			Rust
		
	
	
	
	
	
			
		
		
	
	
			73 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			Rust
		
	
	
	
	
	
//! Skinned mesh example with mesh and joints data loaded from a glTF file.
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//! Example taken from <https://github.com/KhronosGroup/glTF-Tutorials/blob/master/gltfTutorial/gltfTutorial_019_SimpleSkin.md>
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use std::f32::consts::*;
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use bevy::{pbr::AmbientLight, prelude::*, render::mesh::skinning::SkinnedMesh};
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fn main() {
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    App::new()
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        .add_plugins(DefaultPlugins)
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        .insert_resource(AmbientLight {
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            brightness: 1.0,
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            ..default()
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        })
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        .add_startup_system(setup)
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        .add_system(joint_animation)
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        .run();
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}
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fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
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    // Create a camera
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    commands.spawn(Camera3dBundle {
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        transform: Transform::from_xyz(-2.0, 2.5, 5.0).looking_at(Vec3::ZERO, Vec3::Y),
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        ..default()
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    });
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    // Spawn the first scene in `models/SimpleSkin/SimpleSkin.gltf`
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    commands.spawn(SceneBundle {
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        scene: asset_server.load("models/SimpleSkin/SimpleSkin.gltf#Scene0"),
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        ..default()
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    });
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}
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/// The scene hierarchy currently looks somewhat like this:
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///
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/// ```ignore
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/// <Parent entity>
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///   + Mesh node (without `PbrBundle` or `SkinnedMesh` component)
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///     + Skinned mesh entity (with `PbrBundle` and `SkinnedMesh` component, created by glTF loader)
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///     + First joint
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///       + Second joint
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/// ```
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///
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/// In this example, we want to get and animate the second joint.
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/// It is similar to the animation defined in `models/SimpleSkin/SimpleSkin.gltf`.
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fn joint_animation(
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    time: Res<Time>,
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    parent_query: Query<&Parent, With<SkinnedMesh>>,
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    children_query: Query<&Children>,
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    mut transform_query: Query<&mut Transform>,
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) {
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    // Iter skinned mesh entity
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    for skinned_mesh_parent in &parent_query {
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        // Mesh node is the parent of the skinned mesh entity.
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        let mesh_node_entity = skinned_mesh_parent.get();
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        // Get `Children` in the mesh node.
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        let mesh_node_children = children_query.get(mesh_node_entity).unwrap();
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        // First joint is the second child of the mesh node.
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        let first_joint_entity = mesh_node_children[1];
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        // Get `Children` in the first joint.
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        let first_joint_children = children_query.get(first_joint_entity).unwrap();
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        // Second joint is the first child of the first joint.
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        let second_joint_entity = first_joint_children[0];
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        // Get `Transform` in the second joint.
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        let mut second_joint_transform = transform_query.get_mut(second_joint_entity).unwrap();
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        second_joint_transform.rotation =
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            Quat::from_rotation_z(FRAC_PI_2 * time.elapsed_seconds().sin());
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    }
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}
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