replacing heirarchy works without picking enabled

examples/3d_scene_heirarchy.rs

@@ -0,0 +1,129 @@
+use bevy::prelude::*;
+use bevy_mod_picking::{
+    DebugCursorPickingPlugin, DebugEventsPickingPlugin, DefaultPickingPlugins, PickableBundle,
+    PickingCameraBundle,
+};
+
+fn main() {
+    App::build()
+        .insert_resource(WindowDescriptor {
+            vsync: false, // Disabled for this demo to remove vsync as a source of input latency
+            ..Default::default()
+        })
+        .add_plugins(DefaultPlugins)
+        // .add_plugin(DefaultPickingPlugins)
+        // .add_plugin(DebugCursorPickingPlugin)
+        // .add_plugin(DebugEventsPickingPlugin)
+        .add_startup_system(setup.system())
+        .add_system(update.system())
+        .run();
+}
+
+/// set up a simple 3D scene
+fn setup(
+    mut commands: Commands,
+    mut meshes: ResMut<Assets<Mesh>>,
+    mut materials: ResMut<Assets<StandardMaterial>>,
+) {
+    // plane
+    // commands
+    //     .spawn_bundle(PbrBundle {
+    //         mesh: meshes.add(Mesh::from(shape::Plane { size: 5.0 })),
+    //         material: materials.add(Color::rgb(0.3, 0.5, 0.3).into()),
+    //         ..Default::default()
+    //     })
+    //     .insert_bundle(PickableBundle::default());
+
+    // cube
+    let mut root = commands
+        .spawn_bundle(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::default()
+        });
+        // root.insert_bundle(PickableBundle::default());
+
+        let children = [
+            (-1., -1., -1.),
+            (-1., -1., 1.),
+            (-1., 1., 1.), 
+            (-1., 1., -1.),
+            (1., 1., 1.),
+            (1., 1., -1.),
+            (1., -1., 1.),
+            (1., -1., -1.),
+
+        ];
+        for origin in children.iter() {
+            println!("{:?}", origin);
+            root.with_children(|parent| {
+                parent.spawn_bundle(PbrBundle {
+                    mesh: meshes.add(Mesh::from(shape::Cube { size: 0.4 })),
+                    material: materials.add(Color::rgb(0.8, 0.7, 0.6).into()),
+                    transform: Transform::from_xyz(origin.0, origin.1, origin.2),
+                    ..Default::default()
+                });
+                // .insert_bundle(PickableBundle::default());
+
+            });
+        }
+
+    // light
+    commands.spawn_bundle(PointLightBundle {
+        transform: Transform::from_xyz(4.0, 8.0, 4.0),
+        ..Default::default()
+    });
+    // camera
+    commands
+        .spawn_bundle(PerspectiveCameraBundle {
+            transform: Transform::from_xyz(-2.0, 2.5, 10.0).looking_at(Vec3::ZERO, Vec3::Y),
+            ..Default::default()
+        });
+        // .insert_bundle(PickingCameraBundle::default());
+}
+
+
+fn update (
+    mut commands: Commands,
+    mut parents_query: Query<(Entity, &Children)>,
+    mut total_query: Query<Entity>,
+    mut meshes: ResMut<Assets<Mesh>>,
+    mut materials: ResMut<Assets<StandardMaterial>>,   
+    keyboard: Res<Input<KeyCode>>,
+
+) {
+    if !keyboard.just_pressed(KeyCode::Space) {
+        return;
+    }
+    println!("pressed");
+    println!("total elements: {}", total_query.iter().len());
+    let child_origins = [
+            (-1., -1., -1.),
+            (-1., -1., 1.),
+            (-1., 1., 1.),
+            (-1., 1., -1.),
+            (1., 1., 1.),
+            (1., 1., -1.),
+            (1., -1., 1.),
+            (1., -1., -1.),
+
+        ];
+    for (parent, children) in parents_query.iter_mut() {
+        for child in children.iter() {
+            commands.entity(*child).despawn();
+        }
+        for origin in child_origins.iter() {
+            // println!("{:?}", origin);
+            commands.entity(parent).with_children(|parent| {  
+                parent.spawn_bundle(PbrBundle {
+                    mesh: meshes.add(Mesh::from(shape::Cube { size: 0.4 })),
+                    material: materials.add(Color::rgb(0.8, 0.7, 0.6).into()),
+                    transform: Transform::from_xyz(origin.0, origin.1, origin.2),
+                    ..Default::default()
+                });
+                // .insert_bundle(PickableBundle::default());
+            });
+        }
+    }
+}