Support Warning
WebGPU is currently only supported on Chrome starting with version 113, and only on desktop. If they don't work on your configuration, you can check the WebGL2 examples here.//! Create and play an animation defined by code that operates on the [`Transform`] component.
use std::f32::consts::PI;
use bevy::prelude::*;
fn main() {
App::new()
.add_plugins(DefaultPlugins)
.insert_resource(AmbientLight {
color: Color::WHITE,
brightness: 1.0,
})
.add_systems(Startup, setup)
.run();
}
fn setup(
mut commands: Commands,
mut meshes: ResMut<Assets<Mesh>>,
mut materials: ResMut<Assets<StandardMaterial>>,
mut animations: ResMut<Assets<AnimationClip>>,
) {
// Camera
commands.spawn(Camera3dBundle {
transform: Transform::from_xyz(-2.0, 2.5, 5.0).looking_at(Vec3::ZERO, Vec3::Y),
..default()
});
// The animation API uses the `Name` component to target entities
let planet = Name::new("planet");
let orbit_controller = Name::new("orbit_controller");
let satellite = Name::new("satellite");
// Creating the animation
let mut animation = AnimationClip::default();
// A curve can modify a single part of a transform, here the translation
animation.add_curve_to_path(
EntityPath {
parts: vec![planet.clone()],
},
VariableCurve {
keyframe_timestamps: vec![0.0, 1.0, 2.0, 3.0, 4.0],
keyframes: Keyframes::Translation(vec![
Vec3::new(1.0, 0.0, 1.0),
Vec3::new(-1.0, 0.0, 1.0),
Vec3::new(-1.0, 0.0, -1.0),
Vec3::new(1.0, 0.0, -1.0),
// in case seamless looping is wanted, the last keyframe should
// be the same as the first one
Vec3::new(1.0, 0.0, 1.0),
]),
},
);
// Or it can modify the rotation of the transform.
// To find the entity to modify, the hierarchy will be traversed looking for
// an entity with the right name at each level
animation.add_curve_to_path(
EntityPath {
parts: vec![planet.clone(), orbit_controller.clone()],
},
VariableCurve {
keyframe_timestamps: vec![0.0, 1.0, 2.0, 3.0, 4.0],
keyframes: Keyframes::Rotation(vec![
Quat::IDENTITY,
Quat::from_axis_angle(Vec3::Y, PI / 2.),
Quat::from_axis_angle(Vec3::Y, PI / 2. * 2.),
Quat::from_axis_angle(Vec3::Y, PI / 2. * 3.),
Quat::IDENTITY,
]),
},
);
// If a curve in an animation is shorter than the other, it will not repeat
// until all other curves are finished. In that case, another animation should
// be created for each part that would have a different duration / period
animation.add_curve_to_path(
EntityPath {
parts: vec![planet.clone(), orbit_controller.clone(), satellite.clone()],
},
VariableCurve {
keyframe_timestamps: vec![0.0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0],
keyframes: Keyframes::Scale(vec![
Vec3::splat(0.8),
Vec3::splat(1.2),
Vec3::splat(0.8),
Vec3::splat(1.2),
Vec3::splat(0.8),
Vec3::splat(1.2),
Vec3::splat(0.8),
Vec3::splat(1.2),
Vec3::splat(0.8),
]),
},
);
// There can be more than one curve targeting the same entity path
animation.add_curve_to_path(
EntityPath {
parts: vec![planet.clone(), orbit_controller.clone(), satellite.clone()],
},
VariableCurve {
keyframe_timestamps: vec![0.0, 1.0, 2.0, 3.0, 4.0],
keyframes: Keyframes::Rotation(vec![
Quat::IDENTITY,
Quat::from_axis_angle(Vec3::Y, PI / 2.),
Quat::from_axis_angle(Vec3::Y, PI / 2. * 2.),
Quat::from_axis_angle(Vec3::Y, PI / 2. * 3.),
Quat::IDENTITY,
]),
},
);
// Create the animation player, and set it to repeat
let mut player = AnimationPlayer::default();
player.play(animations.add(animation)).repeat();
// Create the scene that will be animated
// First entity is the planet
commands
.spawn((
PbrBundle {
mesh: meshes.add(Mesh::try_from(shape::Icosphere::default()).unwrap()),
material: materials.add(Color::rgb(0.8, 0.7, 0.6).into()),
..default()
},
// Add the Name component, and the animation player
planet,
player,
))
.with_children(|p| {
// This entity is just used for animation, but doesn't display anything
p.spawn((
SpatialBundle::INHERITED_IDENTITY,
// Add the Name component
orbit_controller,
))
.with_children(|p| {
// The satellite, placed at a distance of the planet
p.spawn((
PbrBundle {
transform: Transform::from_xyz(1.5, 0.0, 0.0),
mesh: meshes.add(Mesh::from(shape::Cube { size: 0.5 })),
material: materials.add(Color::rgb(0.3, 0.9, 0.3).into()),
..default()
},
// Add the Name component
satellite,
));
});
});
}