d9aac887b5
# Objective A better alternative version of #10843. Currently, Bevy has a single `Ray` struct for 3D. To allow better interoperability with Bevy's primitive shapes (#10572) and some third party crates (that handle e.g. spatial queries), it would be very useful to have separate versions for 2D and 3D respectively. ## Solution Separate `Ray` into `Ray2d` and `Ray3d`. These new structs also take advantage of the new primitives by using `Direction2d`/`Direction3d` for the direction: ```rust pub struct Ray2d { pub origin: Vec2, pub direction: Direction2d, } pub struct Ray3d { pub origin: Vec3, pub direction: Direction3d, } ``` and by using `Plane2d`/`Plane3d` in `intersect_plane`: ```rust impl Ray2d { // ... pub fn intersect_plane(&self, plane_origin: Vec2, plane: Plane2d) -> Option<f32> { // ... } } ``` --- ## Changelog ### Added - `Ray2d` and `Ray3d` - `Ray2d::new` and `Ray3d::new` constructors - `Plane2d::new` and `Plane3d::new` constructors ### Removed - Removed `Ray` in favor of `Ray3d` ### Changed - `direction` is now a `Direction2d`/`Direction3d` instead of a vector, which provides guaranteed normalization - `intersect_plane` now takes a `Plane2d`/`Plane3d` instead of just a vector for the plane normal - `Direction2d` and `Direction3d` now derive `Serialize` and `Deserialize` to preserve ray (de)serialization ## Migration Guide `Ray` has been renamed to `Ray3d`. ### Ray creation Before: ```rust Ray { origin: Vec3::ZERO, direction: Vec3::new(0.5, 0.6, 0.2).normalize(), } ``` After: ```rust // Option 1: Ray3d { origin: Vec3::ZERO, direction: Direction3d::new(Vec3::new(0.5, 0.6, 0.2)).unwrap(), } // Option 2: Ray3d::new(Vec3::ZERO, Vec3::new(0.5, 0.6, 0.2)) ``` ### Plane intersections Before: ```rust let result = ray.intersect_plane(Vec2::X, Vec2::Y); ``` After: ```rust let result = ray.intersect_plane(Vec2::X, Plane2d::new(Vec2::Y)); ```
73 lines
2.0 KiB
Rust
73 lines
2.0 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) =
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ray.intersect_plane(ground.translation(), primitives::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.).into()),
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material: materials.add(Color::rgb(0.3, 0.5, 0.3).into()),
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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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..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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