add plane below the player

src/world.rs

@@ -58,6 +58,13 @@ pub fn setup(
         ..default()
     });
 
+    commands.spawn(PbrBundle {
+        mesh: meshes.add(Plane3d::default().mesh().size(20.0, 20.0)),
+        transform: Transform::from_xyz(0.0, -20.0, 0.0),
+        material: white_handle,
+        ..default()
+    });
+
     // Space is DARK
     ambient_light.brightness = 0.0;