bevy/examples/animation/gltf_skinned_mesh.rs
Cameron 7989cb2650 Add global time scaling (#5752)
# 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.
2022-10-22 18:52:29 +00:00

72 lines
2.6 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::{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(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(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 {
// Mesh node is the parent of the skinned mesh entity.
let mesh_node_entity = skinned_mesh_parent.get();
// 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_rotation_z(FRAC_PI_2 * time.elapsed_seconds().sin());
}
}