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		7989cb2650
		
	
	
	
	
		
			
			# Objective - Make `Time` API more consistent. - Support time accel/decel/pause. ## Solution This is just the `Time` half of #3002. I was told that part isn't controversial. - Give the "delta time" and "total elapsed time" methods `f32`, `f64`, and `Duration` variants with consistent naming. - Implement accelerating / decelerating the passage of time. - Implement stopping time. --- ## Changelog - Changed `time_since_startup` to `elapsed` because `time.time_*` is just silly. - Added `relative_speed` and `set_relative_speed` methods. - Added `is_paused`, `pause`, `unpause` , and methods. (I'd prefer `resume`, but `unpause` matches `Timer` API.) - Added `raw_*` variants of the "delta time" and "total elapsed time" methods. - Added `first_update` method because there's a non-zero duration between startup and the first update. ## Migration Guide - `time.time_since_startup()` -> `time.elapsed()` - `time.seconds_since_startup()` -> `time.elapsed_seconds_f64()` - `time.seconds_since_startup_wrapped_f32()` -> `time.elapsed_seconds_wrapped()` If you aren't sure which to use, most systems should continue to use "scaled" time (e.g. `time.delta_seconds()`). The realtime "unscaled" time measurements (e.g. `time.raw_delta_seconds()`) are mostly for debugging and profiling.
		
			
				
	
	
		
			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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| 
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| use std::f32::consts::*;
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| 
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| use bevy::{pbr::AmbientLight, prelude::*, render::mesh::skinning::SkinnedMesh};
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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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| 
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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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