docs/bevy/examples/animation/animated_transform.rs 6.4 K · 173 lines · raw · history

1 //! Create and play an animation defined by code that operates on the [`Transform`] component.
2
3 use std::f32::consts::PI;
4
5 use bevy::{
6 animation::{animated_field, AnimatedBy, AnimationTargetId},
7 prelude::*,
8 };
9
10 fn main() {
11 App::new()
12 .add_plugins(DefaultPlugins)
13 .insert_resource(GlobalAmbientLight {
14 color: Color::WHITE,
15 brightness: 150.0,
16 ..default()
17 })
18 .add_systems(Startup, setup)
19 .run();
20 }
21
22 fn setup(
23 mut commands: Commands,
24 mut meshes: ResMut<Assets<Mesh>>,
25 mut materials: ResMut<Assets<StandardMaterial>>,
26 mut animations: ResMut<Assets<AnimationClip>>,
27 mut graphs: ResMut<Assets<AnimationGraph>>,
28 ) {
29 // Camera
30 commands.spawn((
31 Camera3d::default(),
32 Transform::from_xyz(-2.0, 2.5, 5.0).looking_at(Vec3::ZERO, Vec3::Y),
33 ));
34
35 // Light
36 commands.spawn((
37 PointLight {
38 intensity: 500_000.0,
39 ..default()
40 },
41 Transform::from_xyz(0.0, 2.5, 0.0),
42 ));
43
44 // Let's use the `Name` component to target entities. We can use anything we
45 // like, but names are convenient.
46 let planet = Name::new("planet");
47 let orbit_controller = Name::new("orbit_controller");
48 let satellite = Name::new("satellite");
49
50 // Creating the animation
51 let mut animation = AnimationClip::default();
52 // A curve can modify a single part of a transform: here, the translation.
53 let planet_animation_target_id = AnimationTargetId::from_name(&planet);
54 animation.add_curve_to_target(
55 planet_animation_target_id,
56 AnimatableCurve::new(
57 animated_field!(Transform::translation),
58 UnevenSampleAutoCurve::new([0.0, 1.0, 2.0, 3.0, 4.0].into_iter().zip([
59 Vec3::new(1.0, 0.0, 1.0),
60 Vec3::new(-1.0, 0.0, 1.0),
61 Vec3::new(-1.0, 0.0, -1.0),
62 Vec3::new(1.0, 0.0, -1.0),
63 // in case seamless looping is wanted, the last keyframe should
64 // be the same as the first one
65 Vec3::new(1.0, 0.0, 1.0),
66 ]))
67 .expect("should be able to build translation curve because we pass in valid samples"),
68 ),
69 );
70 // Or it can modify the rotation of the transform.
71 // To find the entity to modify, the hierarchy will be traversed looking for
72 // an entity with the right name at each level.
73 let orbit_controller_animation_target_id =
74 AnimationTargetId::from_names([planet.clone(), orbit_controller.clone()].iter());
75 animation.add_curve_to_target(
76 orbit_controller_animation_target_id,
77 AnimatableCurve::new(
78 animated_field!(Transform::rotation),
79 UnevenSampleAutoCurve::new([0.0, 1.0, 2.0, 3.0, 4.0].into_iter().zip([
80 Quat::IDENTITY,
81 Quat::from_axis_angle(Vec3::Y, PI / 2.),
82 Quat::from_axis_angle(Vec3::Y, PI / 2. * 2.),
83 Quat::from_axis_angle(Vec3::Y, PI / 2. * 3.),
84 Quat::IDENTITY,
85 ]))
86 .expect("Failed to build rotation curve"),
87 ),
88 );
89 // If a curve in an animation is shorter than the other, it will not repeat
90 // until all other curves are finished. In that case, another animation should
91 // be created for each part that would have a different duration / period.
92 let satellite_animation_target_id = AnimationTargetId::from_names(
93 [planet.clone(), orbit_controller.clone(), satellite.clone()].iter(),
94 );
95 animation.add_curve_to_target(
96 satellite_animation_target_id,
97 AnimatableCurve::new(
98 animated_field!(Transform::scale),
99 UnevenSampleAutoCurve::new(
100 [0.0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0]
101 .into_iter()
102 .zip([
103 Vec3::splat(0.8),
104 Vec3::splat(1.2),
105 Vec3::splat(0.8),
106 Vec3::splat(1.2),
107 Vec3::splat(0.8),
108 Vec3::splat(1.2),
109 Vec3::splat(0.8),
110 Vec3::splat(1.2),
111 Vec3::splat(0.8),
112 ]),
113 )
114 .expect("Failed to build scale curve"),
115 ),
116 );
117 // There can be more than one curve targeting the same entity path.
118 animation.add_curve_to_target(
119 AnimationTargetId::from_names(
120 [planet.clone(), orbit_controller.clone(), satellite.clone()].iter(),
121 ),
122 AnimatableCurve::new(
123 animated_field!(Transform::rotation),
124 UnevenSampleAutoCurve::new([0.0, 1.0, 2.0, 3.0, 4.0].into_iter().zip([
125 Quat::IDENTITY,
126 Quat::from_axis_angle(Vec3::Y, PI / 2.),
127 Quat::from_axis_angle(Vec3::Y, PI / 2. * 2.),
128 Quat::from_axis_angle(Vec3::Y, PI / 2. * 3.),
129 Quat::IDENTITY,
130 ]))
131 .expect("should be able to build translation curve because we pass in valid samples"),
132 ),
133 );
134
135 // Create the animation graph
136 let (graph, animation_index) = AnimationGraph::from_clip(animations.add(animation));
137
138 // Create the animation player, and set it to repeat
139 let mut player = AnimationPlayer::default();
140 player.play(animation_index).repeat();
141
142 // Create the scene that will be animated
143 // First entity is the planet
144 let planet_entity = commands
145 .spawn((
146 Mesh3d(meshes.add(Sphere::default())),
147 MeshMaterial3d(materials.add(Color::srgb(0.8, 0.7, 0.6))),
148 // Add the animation graph and player
149 planet,
150 AnimationGraphHandle(graphs.add(graph)),
151 player,
152 ))
153 .id();
154 commands.entity(planet_entity).insert((
155 planet_animation_target_id,
156 AnimatedBy(planet_entity),
157 children![(
158 Transform::default(),
159 Visibility::default(),
160 orbit_controller,
161 orbit_controller_animation_target_id,
162 AnimatedBy(planet_entity),
163 children![(
164 Mesh3d(meshes.add(Cuboid::new(0.5, 0.5, 0.5))),
165 MeshMaterial3d(materials.add(Color::srgb(0.3, 0.9, 0.3))),
166 Transform::from_xyz(1.5, 0.0, 0.0),
167 satellite_animation_target_id,
168 AnimatedBy(planet_entity),
169 satellite,
170 )],
171 )],
172 ));
173 }