cubic_curve.rs:
use bevy::{
color::palettes::css::{ORANGE, SILVER, WHITE},
math::vec3,
prelude::*,
};
#[derive(Component)]
struct Curve(CubicCurve<Vec3>);
fn main() {
App::new()
.add_plugins(DefaultPlugins)
.add_systems(Startup, setup)
.add_systems(Update, animate_cube)
.run();
}
fn setup(
mut commands: Commands,
mut meshes: ResMut<Assets<Mesh>>,
mut materials: ResMut<Assets<StandardMaterial>>,
) {
let points = [[
vec3(-6., 2., 0.),
vec3(12., 8., 0.),
vec3(-12., 8., 0.),
vec3(6., 2., 0.),
]];
let bezier = CubicBezier::new(points).to_curve();
commands.spawn((
PbrBundle {
mesh: meshes.add(Cuboid::default()),
material: materials.add(Color::from(ORANGE)),
transform: Transform::from_translation(points[0][0]),
..default()
},
Curve(bezier),
));
commands.spawn(PointLightBundle {
point_light: PointLight {
shadows_enabled: true,
intensity: 10_000_000.,
range: 100.0,
..default()
},
transform: Transform::from_xyz(8., 16., 8.),
..default()
});
commands.spawn(PbrBundle {
mesh: meshes.add(Plane3d::default().mesh().size(50., 50.)),
material: materials.add(Color::from(SILVER)),
..default()
});
commands.spawn(Camera3dBundle {
transform: Transform::from_xyz(0., 6., 12.).looking_at(Vec3::new(0., 3., 0.), Vec3::Y),
..default()
});
}
fn animate_cube(time: Res<Time>, mut query: Query<(&mut Transform, &Curve)>, mut gizmos: Gizmos) {
let t = (time.elapsed_seconds().sin() + 1.) / 2.;
for (mut transform, cubic_curve) in &mut query {
gizmos.linestrip(cubic_curve.0.iter_positions(50), WHITE);
transform.translation = cubic_curve.0.position(t);
}
}