3D Rendering / 3D Gizmos

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Support Warning

WebGPU is currently only supported on Chrome starting with version 113, and only on desktop. If they don't work on your configuration, you can check the WebGL2 examples here.
Support for WebGPU in Bevy hasn't been released yet, this example has been compiled using the main branch.

//! This example demonstrates Bevy's immediate mode drawing API intended for visual debugging.
use std::f32::consts::PI;

use bevy::prelude::*;

fn main() {
    App::new()
        .add_plugins(DefaultPlugins)
        .add_systems(Startup, setup)
        .add_systems(Update, (system, rotate_camera, update_config))
        .run();
}

fn setup(
    mut commands: Commands,
    mut meshes: ResMut<Assets<Mesh>>,
    mut materials: ResMut<Assets<StandardMaterial>>,
) {
    commands.spawn(Camera3dBundle {
        transform: Transform::from_xyz(0., 1.5, 6.).looking_at(Vec3::ZERO, Vec3::Y),
        ..default()
    });
    // plane
    commands.spawn(PbrBundle {
        mesh: meshes.add(Mesh::from(shape::Plane::from_size(5.0))),
        material: materials.add(Color::rgb(0.3, 0.5, 0.3).into()),
        ..default()
    });
    // cube
    commands.spawn(PbrBundle {
        mesh: meshes.add(Mesh::from(shape::Cube { size: 1.0 })),
        material: materials.add(Color::rgb(0.8, 0.7, 0.6).into()),
        transform: Transform::from_xyz(0.0, 0.5, 0.0),
        ..default()
    });
    // light
    commands.spawn(PointLightBundle {
        point_light: PointLight {
            intensity: 1500.0,
            shadows_enabled: true,
            ..default()
        },
        transform: Transform::from_xyz(4.0, 8.0, 4.0),
        ..default()
    });

    // example instructions
    commands.spawn(
        TextBundle::from_section(
            "Press 't' to toggle drawing gizmos on top of everything else in the scene",
            TextStyle {
                font_size: 20.,
                ..default()
            },
        )
        .with_style(Style {
            position_type: PositionType::Absolute,
            top: Val::Px(12.0),
            left: Val::Px(12.0),
            ..default()
        }),
    );
}

fn system(mut gizmos: Gizmos, time: Res<Time>) {
    gizmos.cuboid(
        Transform::from_translation(Vec3::Y * -0.5).with_scale(Vec3::new(5., 1., 2.)),
        Color::BLACK,
    );
    gizmos.rect(
        Vec3::new(time.elapsed_seconds().cos() * 2.5, 1., 0.),
        Quat::from_rotation_y(PI / 2.),
        Vec2::splat(2.),
        Color::GREEN,
    );

    gizmos.sphere(
        Vec3::new(1., 0.5, 0.),
        Quat::IDENTITY,
        0.5,
        Color::RED.with_a(0.5),
    );

    for y in [0., 0.5, 1.] {
        gizmos.ray(
            Vec3::new(1., y, 0.),
            Vec3::new(-3., (time.elapsed_seconds() * 3.).sin(), 0.),
            Color::BLUE,
        );
    }

    // Circles have 32 line-segments by default.
    gizmos.circle(Vec3::ZERO, Vec3::Y, 3., Color::BLACK);
    // You may want to increase this for larger circles or spheres.
    gizmos
        .circle(Vec3::ZERO, Vec3::Y, 3.1, Color::NAVY)
        .segments(64);
    gizmos
        .sphere(Vec3::ZERO, Quat::IDENTITY, 3.2, Color::BLACK)
        .circle_segments(64);
}

fn rotate_camera(mut query: Query<&mut Transform, With<Camera>>, time: Res<Time>) {
    let mut transform = query.single_mut();

    transform.rotate_around(Vec3::ZERO, Quat::from_rotation_y(time.delta_seconds() / 2.));
}

fn update_config(mut gizmo_config: ResMut<GizmoConfig>, keyboard: Res<Input<KeyCode>>) {
    if keyboard.just_pressed(KeyCode::T) {
        gizmo_config.on_top = !gizmo_config.on_top;
    }
}