Switched to a 3D view.

app/src/main.rs

@@ -1,34 +1,49 @@
-use bevy::color::palettes::basic::RED;
-use bevy::log;
 use bevy::prelude::*;                   // Core Bevy types
 
 const GRAVITY: f32 = -20.0;
+const CAMERA_SPEED: f32 = 5.0; // units per second
 
 fn main() {
     App::new()
         .add_plugins(DefaultPlugins)
         .add_systems(Startup, setup)
         .add_systems(Update, (apply_gravity, velocity_timestep).chain())
+        .add_systems(Update, move_camera)
         .run();
 }
 
-fn setup(mut commands: Commands, mut meshes: ResMut<Assets<Mesh>>, mut materials: ResMut<Assets<ColorMaterial>>) {
-
-    commands.spawn(Camera2d);
-
-    let shape =meshes.add(Circle::new(50.0));
-
-    commands.spawn((Mesh2d(shape.clone()), MeshMaterial2d(materials.add(Color::from(RED))), Transform::from_xyz(100.0, 0.0, 0.0), Velocity(vec3(
-        0.0,
-        100.0,
-        0.0
-    ))));
-
-    commands.spawn((Mesh2d(shape.clone()), MeshMaterial2d(materials.add(Color::from(RED))), Transform::from_xyz(300.0, 0.0, 0.0), Velocity(vec3(
-        0.0,
-        50.0,
-        0.0
-    ))));}
+/// set up a simple 3D scene
+fn setup(
+    mut commands: Commands,
+    mut meshes: ResMut<Assets<Mesh>>,
+    mut materials: ResMut<Assets<StandardMaterial>>,
+) {
+    // circular base
+    commands.spawn((
+        Mesh3d(meshes.add(Circle::new(4.0))),
+        MeshMaterial3d(materials.add(Color::WHITE)),
+        Transform::from_rotation(Quat::from_rotation_x(-std::f32::consts::FRAC_PI_2)),
+    ));
+    // cube
+    commands.spawn((
+        Mesh3d(meshes.add(Cuboid::new(1.0, 1.0, 1.0))),
+        MeshMaterial3d(materials.add(Color::srgb_u8(124, 144, 255))),
+        Transform::from_xyz(0.0, 0.5, 0.0),
+    ));
+    // light
+    commands.spawn((
+        PointLight {
+            shadows_enabled: true,
+            ..default()
+        },
+        Transform::from_xyz(4.0, 8.0, 4.0),
+    ));
+    // camera
+    commands.spawn((
+        Camera3d::default(),
+        Transform::from_xyz(-2.5, 4.5, 9.0).looking_at(Vec3::ZERO, Vec3::Y),
+    ));
+}
 
 #[derive(Component)]
 struct Velocity(Vec3);
@@ -44,3 +59,25 @@ fn apply_gravity(time: Res<Time>, mut query: Query<&mut Velocity>) {
         velocity.0.y += GRAVITY * time.delta_secs();
     }
 }
+
+fn move_camera(
+    time: Res<Time>,
+    keyboard_input: Res<ButtonInput<KeyCode>>,
+    mut camera: Single<&mut Transform, With<Camera3d>>,
+) {
+    let mut direction = Vec3::ZERO;
+
+    if keyboard_input.pressed(KeyCode::KeyW) {
+        direction.y += 1.0;
+    }
+    if keyboard_input.pressed(KeyCode::KeyS) {
+        direction.y -= 1.0;
+    }
+    if keyboard_input.pressed(KeyCode::KeyA) {
+        direction.x -= 1.0;
+    }
+    if keyboard_input.pressed(KeyCode::KeyD) {
+        direction.x += 1.0;
+    }
+    camera.translation += direction * CAMERA_SPEED * time.delta_secs(); // or use time.delta_seconds()
+}