Work on fixing the remaining issues / error messages with World overrides.

scene/3d/camera.cpp

@@ -157,12 +157,12 @@ void Camera::_notification(int p_what) {
 		} break;
 		case NOTIFICATION_BECAME_CURRENT: {
 			if (viewport) {
-				viewport->find_world_3d()->_register_camera(this);
+				viewport->_world_3d_register_camera(this);
 			}
 		} break;
 		case NOTIFICATION_LOST_CURRENT: {
 			if (viewport) {
-				viewport->find_world_3d()->_remove_camera(this);
+				viewport->_world_3d_remove_camera(this);
 			}
 		} break;
 	}

scene/main/world.cpp

@@ -2,6 +2,7 @@
 
 #include "core/config/engine.h"
 #include "core/core_string_names.h"
+#include "scene/3d/camera.h"
 #include "scene/3d/spatial.h"
 #include "scene/3d/world_environment_3d.h"
 #include "scene/resources/world_2d.h"
@@ -164,6 +165,28 @@ Ref<World3D> World::find_world_3d() const {
 	}
 }
 
+Ref<World2D> World::find_world_2d_no_override() const {
+	if (world_2d.is_valid()) {
+		return world_2d;
+	} else if (_parent_world) {
+		return _parent_world->find_world_2d();
+	} else {
+		return Ref<World2D>();
+	}
+}
+
+Ref<World3D> World::find_world_3d_no_override() const {
+	if (own_world_3d.is_valid()) {
+		return own_world_3d;
+	} else if (world_3d.is_valid()) {
+		return world_3d;
+	} else if (_parent_world) {
+		return _parent_world->find_world_3d();
+	} else {
+		return Ref<World3D>();
+	}
+}
+
 World *World::get_override_world() {
 	return _override_world;
 }
@@ -192,6 +215,8 @@ void World::set_override_world(World *p_world) {
 		old_world->_remove_overridden_world(this);
 	}
 
+	_clear_override_cameras();
+
 	_override_world = p_world;
 
 	if (_override_world) {
@@ -204,6 +229,7 @@ void World::set_override_world(World *p_world) {
 		if (old_world_3d != new_world_3d) {
 			if (new_world_3d.is_valid()) {
 				old_world_3d->move_cameras_into(new_world_3d);
+
 			} else {
 				ERR_PRINT("!new_world_3d.is_valid()");
 			}
@@ -212,6 +238,10 @@ void World::set_override_world(World *p_world) {
 		ERR_PRINT("!old_world_3d.is_valid()");
 	}
 
+	if (_override_world) {
+		_add_override_cameras_into(_override_world);
+	}
+
 	_on_after_world_override_changed();
 }
 void World::set_override_world_bind(Node *p_world) {
@@ -324,6 +354,63 @@ void World::update_worlds() {
 	find_world_3d()->_update(get_tree()->get_frame());
 }
 
+void World::_world_3d_register_camera(Camera *p_camera) {
+	if (_override_world) {
+		_override_world->_world_3d_register_camera_as_override(p_camera);
+	}
+
+	_world_3d_register_camera_no_override(p_camera);
+}
+
+void World::_world_3d_remove_camera(Camera *p_camera) {
+	if (_override_world) {
+		_override_world->_world_3d_remove_camera_as_override(p_camera);
+	}
+
+	_world_3d_remove_camera_no_override(p_camera);
+}
+
+void World::_world_3d_register_camera_no_override(Camera *p_camera) {
+	find_world_3d_no_override()->_register_camera(p_camera);
+}
+
+void World::_world_3d_remove_camera_no_override(Camera *p_camera) {
+	find_world_3d_no_override()->_remove_camera(p_camera);
+}
+
+void World::_world_3d_register_camera_as_override(Camera *p_camera) {
+	find_world_3d_no_override()->_register_camera(p_camera);
+
+	_override_cameras.push_back(p_camera);
+}
+
+void World::_world_3d_remove_camera_as_override(Camera *p_camera) {
+	find_world_3d_no_override()->_remove_camera(p_camera);
+
+	_override_cameras.erase(p_camera);
+}
+
+void World::_clear_override_cameras() {
+	while (_override_cameras.size() > 0) {
+		_world_3d_remove_camera_as_override(_override_cameras[0]);
+	}
+}
+
+void World::_add_override_cameras_into(World *p_from) {
+	Ref<World3D> w3d = find_world_3d_no_override();
+
+	ERR_FAIL_COND(!w3d.is_valid());
+
+	List<Camera *> cameras;
+	w3d->get_camera_list(&cameras);
+
+	for (List<Camera *>::Element *E = cameras.front(); E; E = E->next()) {
+		Camera *cam = E->get();
+
+		_world_3d_register_camera_as_override(cam);
+	}
+}
+
 World::World() {
 	world_2d = Ref<World2D>(memnew(World2D));
 	_override_world = NULL;

scene/main/world.h

@@ -6,6 +6,7 @@
 
 #include "node.h"
 
+class Camera;
 class World3D;
 class World2D;
 
@@ -27,6 +28,8 @@ public:
 
 	Ref<World2D> find_world_2d() const;
 	Ref<World3D> find_world_3d() const;
+	Ref<World2D> find_world_2d_no_override() const;
+	Ref<World3D> find_world_3d_no_override() const;
 
 	World *get_override_world();
 	World *get_override_world_or_this();
@@ -56,6 +59,15 @@ public:
 
 	void update_worlds();
 
+	void _world_3d_register_camera(Camera *p_camera);
+	void _world_3d_remove_camera(Camera *p_camera);
+	void _world_3d_register_camera_no_override(Camera *p_camera);
+	void _world_3d_remove_camera_no_override(Camera *p_camera);
+	void _world_3d_register_camera_as_override(Camera *p_camera);
+	void _world_3d_remove_camera_as_override(Camera *p_camera);
+	void _clear_override_cameras();
+	void _add_override_cameras_into(World *p_from);
+
 	World();
 	~World();
 
@@ -88,6 +100,7 @@ protected:
 	World *_override_world;
 
 	Vector<World *> _overriding_worlds;
+	Vector<Camera *> _override_cameras;
 };
 
 #endif

scene/resources/world_3d.cpp

@@ -30,9 +30,9 @@
 
 #include "world_3d.h"
 
-#include "core/math/projection.h"
-#include "core/math/octree.h"
 #include "core/config/project_settings.h"
+#include "core/math/octree.h"
+#include "core/math/projection.h"
 #include "scene/3d/camera.h"
 #include "scene/3d/visibility_notifier.h"
 #include "scene/scene_string_names.h"