Only extract added entities, stop nuking render world

crates/bevy_pbr/src/render/light.rs

@@ -181,7 +181,7 @@ pub fn extract_lights(
             &GlobalTransform,
             &ViewVisibility,
             &CubemapFrusta,
-        )>,
+        ), Added<PointLight>>,
     >,
     spot_lights: Extract<
         Query<(
@@ -190,7 +190,7 @@ pub fn extract_lights(
             &GlobalTransform,
             &ViewVisibility,
             &Frustum,
-        )>,
+        ), Added<SpotLight>>,
     >,
     directional_lights: Extract<
         Query<
@@ -206,7 +206,7 @@ pub fn extract_lights(
                 Option<&RenderLayers>,
                 Option<&VolumetricLight>,
             ),
-            Without<SpotLight>,
+            (Without<SpotLight>, Added<DirectionalLight>),
         >,
     >,
     mut previous_point_lights_len: Local<usize>,
@@ -531,8 +531,8 @@ pub fn prepare_lights(
         Entity,
         &ExtractedPointLight,
         AnyOf<(&CubemapFrusta, &Frustum)>,
-    )>,
-    directional_lights: Query<(Entity, &ExtractedDirectionalLight)>,
+    ), Added<ExtractedPointLight>>,
+    directional_lights: Query<(Entity, &ExtractedDirectionalLight), Added<ExtractedDirectionalLight>>,
     mut live_shadow_mapping_lights: Local<EntityHashSet>,
 ) {
     let views_iter = views.iter();

crates/bevy_render/src/camera/camera.rs

@@ -15,6 +15,7 @@ use crate::{
 use bevy_asset::{AssetEvent, AssetId, Assets, Handle};
 use bevy_derive::{Deref, DerefMut};
 use bevy_ecs::{
+    prelude::*,
     change_detection::DetectChanges,
     component::Component,
     entity::Entity,
@@ -842,7 +843,7 @@ pub fn extract_cameras(
             Option<&RenderLayers>,
             Option<&Projection>,
             Has<GpuCulling>,
-        )>,
+        ), Added<Camera>>,
     >,
     primary_window: Extract<Query<Entity, With<PrimaryWindow>>>,
     gpu_preprocessing_support: Res<GpuPreprocessingSupport>,

crates/bevy_render/src/extract_component.rs

@@ -16,6 +16,9 @@ use std::{marker::PhantomData, ops::Deref};
 
 pub use bevy_render_macros::ExtractComponent;
 
+#[derive(Component)]
+pub struct MainWorldEntity(Entity);
+
 /// Stores the index of a uniform inside of [`ComponentUniforms`].
 #[derive(Component)]
 pub struct DynamicUniformIndex<C: Component> {
@@ -209,32 +212,32 @@ impl<T: Asset> ExtractComponent for Handle<T> {
 fn extract_components<C: ExtractComponent>(
     mut commands: Commands,
     mut previous_len: Local<usize>,
-    query: Extract<Query<(Entity, C::QueryData), C::QueryFilter>>,
+    query: Extract<Query<(Entity, C::QueryData), (C::QueryFilter, Added<C>)>>,
 ) {
     let mut values = Vec::with_capacity(*previous_len);
     for (entity, query_item) in &query {
         if let Some(component) = C::extract_component(query_item) {
-            values.push((entity, component));
+            values.push((component, MainWorldEntity(entity)));
         }
     }
     *previous_len = values.len();
-    commands.insert_or_spawn_batch(values);
+    commands.spawn_batch(values);
 }
 
 /// This system extracts all visible components of the corresponding [`ExtractComponent`] type.
 fn extract_visible_components<C: ExtractComponent>(
     mut commands: Commands,
     mut previous_len: Local<usize>,
-    query: Extract<Query<(Entity, &ViewVisibility, C::QueryData), C::QueryFilter>>,
+    query: Extract<Query<(Entity, &ViewVisibility, C::QueryData), (C::QueryFilter, Added<C>)>>,
 ) {
     let mut values = Vec::with_capacity(*previous_len);
     for (entity, view_visibility, query_item) in &query {
         if view_visibility.get() {
             if let Some(component) = C::extract_component(query_item) {
-                values.push((entity, component));
+                values.push((component, MainWorldEntity(entity)));
             }
         }
     }
     *previous_len = values.len();
-    commands.insert_or_spawn_batch(values);
+    commands.spawn_batch(values);
 }

crates/bevy_render/src/lib.rs

@@ -463,9 +463,7 @@ unsafe fn initialize_render_app(app: &mut App) {
                     render_system,
                 )
                     .in_set(RenderSet::Render),
-                World::clear_entities.in_set(RenderSet::Cleanup),
-            ),
-        );
+        ));
 
     render_app.set_extract(|main_world, render_world| {
         #[cfg(feature = "trace")]
@@ -479,7 +477,7 @@ unsafe fn initialize_render_app(app: &mut App) {
             // reserve all existing main world entities for use in render_app
             // they can only be spawned using `get_or_spawn()`
             let total_count = main_world.entities().total_count();
-
+            /*
             assert_eq!(
                 render_world.entities().len(),
                 0,
@@ -492,8 +490,21 @@ unsafe fn initialize_render_app(app: &mut App) {
                     .entities_mut()
                     .flush_and_reserve_invalid_assuming_no_entities(total_count);
             }
+            */
         }
-
+        println!("{}", render_world.entities().len());
+        /*
+        if (render_world.entities().len() < 50) {
+        println!("Entities:");
+        for entity in render_world.iter_entities() {
+            print!("[");
+            for component_info in render_world.inspect_entity(entity.id()).take(5) {
+                print!("{:?}, ", component_info.name());
+            }
+            print!("] ");
+        }
+        }
+        */
         // run extract schedule
         extract(main_world, render_world);
     });

crates/bevy_render/src/view/visibility/range.rs

@@ -8,6 +8,7 @@ use std::{
 
 use bevy_app::{App, Plugin, PostUpdate};
 use bevy_ecs::{
+    prelude::*,
     component::Component,
     entity::Entity,
     query::{Changed, With},
@@ -405,7 +406,7 @@ pub fn check_visibility_ranges(
 /// render world and inserts them into [`RenderVisibilityRanges`].
 pub fn extract_visibility_ranges(
     mut render_visibility_ranges: ResMut<RenderVisibilityRanges>,
-    visibility_ranges_query: Extract<Query<(Entity, &VisibilityRange)>>,
+    visibility_ranges_query: Extract<Query<(Entity, &VisibilityRange), Added<VisibilityRange>>>,
     changed_ranges_query: Extract<Query<Entity, Changed<VisibilityRange>>>,
 ) {
     if changed_ranges_query.is_empty() {

crates/bevy_render/src/view/window/mod.rs

@@ -118,7 +118,7 @@ fn extract_windows(
     mut extracted_windows: ResMut<ExtractedWindows>,
     screenshot_manager: Extract<Res<ScreenshotManager>>,
     mut closing: Extract<EventReader<WindowClosing>>,
-    windows: Extract<Query<(Entity, &Window, &RawHandleWrapper, Option<&PrimaryWindow>)>>,
+    windows: Extract<Query<(Entity, &Window, &RawHandleWrapper, Option<&PrimaryWindow>), Added<Window>>>,
     mut removed: Extract<RemovedComponents<RawHandleWrapper>>,
     mut window_surfaces: ResMut<WindowSurfaces>,
 ) {

crates/bevy_ui/src/render/mod.rs

@@ -725,7 +725,7 @@ pub fn extract_default_ui_camera_view(
     mut commands: Commands,
     mut transparent_render_phases: ResMut<ViewSortedRenderPhases<TransparentUi>>,
     ui_scale: Extract<Res<UiScale>>,
-    query: Extract<Query<(Entity, &Camera), Or<(With<Camera2d>, With<Camera3d>)>>>,
+    query: Extract<Query<(Entity, &Camera), (Or<(With<Camera2d>, With<Camera3d>)>, Added<Camera>)>>,
     mut live_entities: Local<EntityHashSet>,
 ) {
     live_entities.clear();