bevy/examples/3d/3d_viewport_to_world.rs
Robert Walter 8895113784
Use Isometry in bevy_gizmos wherever we can (#14676)
# Objective

- Solves the last bullet in and closes #14319
- Make better use of the `Isometry` types
- Prevent issues like #14655
- Probably simplify and clean up a lot of code through the use of Gizmos
as well (i.e. the 3D gizmos for cylinders circles & lines don't connect
well, probably due to wrong rotations)

## Solution

- go through the `bevy_gizmos` crate and give all methods a slight
workover

## Testing

- For all the changed examples I run `git switch main && cargo rr
--example <X> && git switch <BRANCH> && cargo rr --example <X>` and
compare the visual results
- Check if all doc tests are still compiling
- Check the docs in general and update them !!! 

---

## Migration Guide

The gizmos methods function signature changes as follows:

- 2D
- if it took `position` & `rotation_angle` before ->
`Isometry2d::new(position, Rot2::radians(rotation_angle))`
- if it just took `position` before ->
`Isometry2d::from_translation(position)`
- 3D
- if it took `position` & `rotation` before ->
`Isometry3d::new(position, rotation)`
- if it just took `position` before ->
`Isometry3d::from_translation(position)`
2024-08-28 01:37:19 +00:00

79 lines
2.1 KiB
Rust

//! This example demonstrates how to use the `Camera::viewport_to_world` method.
use bevy::prelude::*;
fn main() {
App::new()
.add_plugins(DefaultPlugins)
.add_systems(Startup, setup)
.add_systems(Update, draw_cursor)
.run();
}
fn draw_cursor(
camera_query: Query<(&Camera, &GlobalTransform)>,
ground_query: Query<&GlobalTransform, With<Ground>>,
windows: Query<&Window>,
mut gizmos: Gizmos,
) {
let (camera, camera_transform) = camera_query.single();
let ground = ground_query.single();
let Some(cursor_position) = windows.single().cursor_position() else {
return;
};
// Calculate a ray pointing from the camera into the world based on the cursor's position.
let Some(ray) = camera.viewport_to_world(camera_transform, cursor_position) else {
return;
};
// Calculate if and where the ray is hitting the ground plane.
let Some(distance) =
ray.intersect_plane(ground.translation(), InfinitePlane3d::new(ground.up()))
else {
return;
};
let point = ray.get_point(distance);
// Draw a circle just above the ground plane at that position.
gizmos.circle(
Isometry3d::new(
point + ground.up() * 0.01,
Quat::from_rotation_arc(Vec3::Z, ground.up().as_vec3()),
),
0.2,
Color::WHITE,
);
}
#[derive(Component)]
struct Ground;
fn setup(
mut commands: Commands,
mut meshes: ResMut<Assets<Mesh>>,
mut materials: ResMut<Assets<StandardMaterial>>,
) {
// plane
commands.spawn((
PbrBundle {
mesh: meshes.add(Plane3d::default().mesh().size(20., 20.)),
material: materials.add(Color::srgb(0.3, 0.5, 0.3)),
..default()
},
Ground,
));
// light
commands.spawn(DirectionalLightBundle {
transform: Transform::from_translation(Vec3::ONE).looking_at(Vec3::ZERO, Vec3::Y),
..default()
});
// camera
commands.spawn(Camera3dBundle {
transform: Transform::from_xyz(15.0, 5.0, 15.0).looking_at(Vec3::ZERO, Vec3::Y),
..default()
});
}