bevy/examples/animation/gltf_skinned_mesh.rs
Tim Overbeek ccb7069e7f
Change ChildOf to Childof { parent: Entity} and support deriving Relationship and RelationshipTarget with named structs (#17905)
# Objective

fixes #17896 

## Solution

Change ChildOf ( Entity ) to ChildOf { parent: Entity }

by doing this we also allow users to use named structs for relationship
derives, When you have more than 1 field in a struct with named fields
the macro will look for a field with the attribute #[relationship] and
all of the other fields should implement the Default trait. Unnamed
fields are still supported.

When u have a unnamed struct with more than one field the macro will
fail.
Do we want to support something like this ? 

```rust
 #[derive(Component)]
 #[relationship_target(relationship = ChildOf)]
 pub struct Children (#[relationship] Entity, u8);
```
I could add this, it but doesn't seem nice.
## Testing

crates/bevy_ecs - cargo test


## Showcase


```rust

use bevy_ecs::component::Component;
use bevy_ecs::entity::Entity;

 #[derive(Component)]
 #[relationship(relationship_target = Children)]
 pub struct ChildOf {
     #[relationship]
     pub parent: Entity,
     internal: u8,
 };

 #[derive(Component)]
 #[relationship_target(relationship = ChildOf)]
 pub struct Children {
     children: Vec<Entity>
 };

```

---------

Co-authored-by: Tim Overbeek <oorbecktim@Tims-MacBook-Pro.local>
Co-authored-by: Tim Overbeek <oorbecktim@c-001-001-042.client.nl.eduvpn.org>
Co-authored-by: Tim Overbeek <oorbecktim@c-001-001-059.client.nl.eduvpn.org>
Co-authored-by: Tim Overbeek <oorbecktim@c-001-001-054.client.nl.eduvpn.org>
Co-authored-by: Tim Overbeek <oorbecktim@c-001-001-027.client.nl.eduvpn.org>
2025-02-27 19:22:17 +00:00

72 lines
2.5 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::*;
use bevy::{math::ops, prelude::*, render::mesh::skinning::SkinnedMesh};
fn main() {
App::new()
.add_plugins(DefaultPlugins)
.insert_resource(AmbientLight {
brightness: 750.0,
..default()
})
.add_systems(Startup, setup)
.add_systems(Update, joint_animation)
.run();
}
fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
// Create a camera
commands.spawn((
Camera3d::default(),
Transform::from_xyz(-2.0, 2.5, 5.0).looking_at(Vec3::new(0.0, 1.0, 0.0), Vec3::Y),
));
// Spawn the first scene in `models/SimpleSkin/SimpleSkin.gltf`
commands.spawn(SceneRoot(asset_server.load(
GltfAssetLabel::Scene(0).from_asset("models/SimpleSkin/SimpleSkin.gltf"),
)));
}
/// The scene hierarchy currently looks somewhat like this:
///
/// ```text
/// <Parent entity>
/// + Mesh node (without `Mesh3d` or `SkinnedMesh` component)
/// + Skinned mesh entity (with `Mesh3d` 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>,
children: Query<&ChildOf, With<SkinnedMesh>>,
parents: Query<&Children>,
mut transform_query: Query<&mut Transform>,
) {
// Iter skinned mesh entity
for child_of in &children {
// Mesh node is the parent of the skinned mesh entity.
let mesh_node_entity = child_of.parent;
// Get `Children` in the mesh node.
let mesh_node_parent = parents.get(mesh_node_entity).unwrap();
// First joint is the second child of the mesh node.
let first_joint_entity = mesh_node_parent[1];
// Get `Children` in the first joint.
let first_joint_children = parents.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_rotation_z(FRAC_PI_2 * ops::sin(time.elapsed_secs()));
}
}