c6f45831e9
# Objective Currently, the `primitives` module is inside of the prelude for `bevy_math`, but the actual primitives are not. This requires either importing the shapes everywhere that uses them, or adding the `primitives::` prefix: ```rust let rectangle = meshes.add(primitives::Rectangle::new(5.0, 2.5)); ``` (Note: meshing isn't actually implemented yet, but it's in #11431) The primitives are meant to be used for a variety of tasks across several crates, like for meshing, bounding volumes, gizmos, colliders, and so on, so I think having them in the prelude is justified. It would make several common tasks a lot more ergonomic. ```rust let rectangle = meshes.add(Rectangle::new(5.0, 2.5)); ``` ## Solution Add `primitives::*` to `bevy_math::prelude`. --------- Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
76 lines
2.1 KiB
Rust
76 lines
2.1 KiB
Rust
//! This example demonstrates how to use the `Camera::viewport_to_world` method.
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use bevy::prelude::*;
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fn main() {
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App::new()
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.add_plugins(DefaultPlugins)
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.add_systems(Startup, setup)
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.add_systems(Update, draw_cursor)
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.run();
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}
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fn draw_cursor(
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camera_query: Query<(&Camera, &GlobalTransform)>,
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ground_query: Query<&GlobalTransform, With<Ground>>,
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windows: Query<&Window>,
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mut gizmos: Gizmos,
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) {
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let (camera, camera_transform) = camera_query.single();
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let ground = ground_query.single();
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let Some(cursor_position) = windows.single().cursor_position() else {
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return;
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};
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// Calculate a ray pointing from the camera into the world based on the cursor's position.
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let Some(ray) = camera.viewport_to_world(camera_transform, cursor_position) else {
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return;
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};
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// Calculate if and where the ray is hitting the ground plane.
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let Some(distance) = ray.intersect_plane(ground.translation(), Plane3d::new(ground.up()))
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else {
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return;
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};
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let point = ray.get_point(distance);
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// Draw a circle just above the ground plane at that position.
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gizmos.circle(point + ground.up() * 0.01, ground.up(), 0.2, Color::WHITE);
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}
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#[derive(Component)]
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struct Ground;
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fn setup(
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mut commands: Commands,
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mut meshes: ResMut<Assets<Mesh>>,
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mut materials: ResMut<Assets<StandardMaterial>>,
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) {
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// plane
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commands.spawn((
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PbrBundle {
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mesh: meshes.add(shape::Plane::from_size(20.)),
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material: materials.add(Color::rgb(0.3, 0.5, 0.3)),
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..default()
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},
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Ground,
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));
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// light
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commands.spawn(DirectionalLightBundle {
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transform: Transform::from_translation(Vec3::ONE).looking_at(Vec3::ZERO, Vec3::Y),
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directional_light: DirectionalLight {
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illuminance: 2000.0,
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..default()
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},
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..default()
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});
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// camera
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commands.spawn(Camera3dBundle {
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transform: Transform::from_xyz(15.0, 5.0, 15.0).looking_at(Vec3::ZERO, Vec3::Y),
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..default()
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});
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}
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