bevy/examples/animation/gltf_skinned_mesh.rs
François c6958b3056 add a SceneBundle to spawn a scene (#2424)
# 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>
2022-06-09 20:34:09 +00:00

74 lines
2.7 KiB
Rust

//! Skinned mesh example with mesh and joints data loaded from a glTF file.
//! Example taken from <https://github.com/KhronosGroup/glTF-Tutorials/blob/master/gltfTutorial/gltfTutorial_019_SimpleSkin.md>
use std::f32::consts::PI;
use bevy::{pbr::AmbientLight, prelude::*, render::mesh::skinning::SkinnedMesh};
fn main() {
App::new()
.add_plugins(DefaultPlugins)
.insert_resource(AmbientLight {
brightness: 1.0,
..default()
})
.add_startup_system(setup)
.add_system(joint_animation)
.run();
}
fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
// Create a camera
commands.spawn_bundle(Camera3dBundle {
transform: Transform::from_xyz(-2.0, 2.5, 5.0).looking_at(Vec3::ZERO, Vec3::Y),
..default()
});
// Spawn the first scene in `models/SimpleSkin/SimpleSkin.gltf`
commands.spawn_bundle(SceneBundle {
scene: asset_server.load("models/SimpleSkin/SimpleSkin.gltf#Scene0"),
..default()
});
}
/// The scene hierarchy currently looks somewhat like this:
///
/// ```ignore
/// <Parent entity>
/// + Mesh node (without `PbrBundle` or `SkinnedMesh` component)
/// + Skinned mesh entity (with `PbrBundle` and `SkinnedMesh` component, created by glTF loader)
/// + First joint
/// + Second joint
/// ```
///
/// In this example, we want to get and animate the second joint.
/// It is similar to the animation defined in `models/SimpleSkin/SimpleSkin.gltf`.
fn joint_animation(
time: Res<Time>,
parent_query: Query<&Parent, With<SkinnedMesh>>,
children_query: Query<&Children>,
mut transform_query: Query<&mut Transform>,
) {
// Iter skinned mesh entity
for skinned_mesh_parent in parent_query.iter() {
// Mesh node is the parent of the skinned mesh entity.
let mesh_node_entity = skinned_mesh_parent.0;
// Get `Children` in the mesh node.
let mesh_node_children = children_query.get(mesh_node_entity).unwrap();
// First joint is the second child of the mesh node.
let first_joint_entity = mesh_node_children[1];
// Get `Children` in the first joint.
let first_joint_children = children_query.get(first_joint_entity).unwrap();
// Second joint is the first child of the first joint.
let second_joint_entity = first_joint_children[0];
// Get `Transform` in the second joint.
let mut second_joint_transform = transform_query.get_mut(second_joint_entity).unwrap();
second_joint_transform.rotation = Quat::from_axis_angle(
Vec3::Z,
0.5 * PI * time.time_since_startup().as_secs_f32().sin(),
);
}
}