bevy/examples/3d/3d_viewport_to_world.rs
Alice Cecile de004da8d5
Rename bevy_render::Color to LegacyColor (#12069)
# Objective

The migration process for `bevy_color` (#12013) will be fairly involved:
there will be hundreds of affected files, and a large number of APIs.

## Solution

To allow us to proceed granularly, we're going to keep both
`bevy_color::Color` (new) and `bevy_render::Color` (old) around until
the migration is complete.

However, simply doing this directly is confusing! They're both called
`Color`, making it very hard to tell when a portion of the code has been
ported.

As discussed in #12056, by renaming the old `Color` type, we can make it
easier to gradually migrate over, one API at a time.

## Migration Guide

THIS MIGRATION GUIDE INTENTIONALLY LEFT BLANK.

This change should not be shipped to end users: delete this section in
the final migration guide!

---------

Co-authored-by: Alice Cecile <alice.i.cecil@gmail.com>
2024-02-24 21:35:32 +00:00

77 lines
2.1 KiB
Rust

//! This example demonstrates how to use the `Camera::viewport_to_world` method.
use bevy::math::primitives::Direction3d;
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(), Plane3d::new(ground.up()))
else {
return;
};
let point = ray.get_point(distance);
// Draw a circle just above the ground plane at that position.
gizmos.circle(
point + ground.up() * 0.01,
Direction3d::new_unchecked(ground.up()), // Up vector is already normalized.
0.2,
LegacyColor::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(LegacyColor::rgb(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()
});
}