Fix New Viewport Texture in Editor Inspector

editor/editor_inspector.cpp

@@ -4138,9 +4138,11 @@ void EditorInspector::_notification(int p_what) {
 			changing++;
 
 			if (update_tree_pending) {
+				if (!update_tree_paused) {
 					update_tree();
 					update_tree_pending = false;
 					pending.clear();
+				}
 
 			} else {
 				while (pending.size()) {
@@ -4247,6 +4249,10 @@ Variant EditorInspector::get_property_clipboard() const {
 	return property_clipboard;
 }
 
+void EditorInspector::set_update_tree_paused(bool p_paused) {
+	update_tree_paused = p_paused;
+}
+
 void EditorInspector::_show_add_meta_dialog() {
 	if (!add_meta_dialog) {
 		add_meta_dialog = memnew(AddMetadataDialog());

editor/editor_inspector.h

@@ -520,6 +520,7 @@ class EditorInspector : public ScrollContainer {
 
 	float refresh_countdown;
 	bool update_tree_pending = false;
+	bool update_tree_paused = false;
 	StringName _prop_edited;
 	StringName property_selected;
 	int property_focusable;
@@ -653,6 +654,8 @@ public:
 	void set_property_clipboard(const Variant &p_value);
 	Variant get_property_clipboard() const;
 
+	void set_update_tree_paused(bool p_paused);
+
 	EditorInspector();
 };
 

editor/editor_properties.cpp

@@ -3122,7 +3122,19 @@ void EditorPropertyResource::_resource_changed(const Ref<Resource> &p_resource)
 
 			add_child(scene_tree);
 			scene_tree->connect("selected", callable_mp(this, &EditorPropertyResource::_viewport_selected));
+			scene_tree->connect("visibility_changed", callable_mp(this, &EditorPropertyResource::_scene_tree_visibility_changed));
 		}
+
+		// We need to pause the inspector to update it's tree to prevent the
+		// recreation of the current EditorPropertyResource instance which contains
+		// the scene tree dialog. EditorInspector recreates all the controls on update tree
+		// and the update tree is triggered by the signal property_list_changed in BaseMaterial3D
+		// when the ViewportTexture is set on the current propecty.
+		EditorInspector *parent_inspector = _get_parent_inspector();
+		if (parent_inspector) {
+			parent_inspector->set_update_tree_paused(true);
+		}
+
 		scene_tree->popup_scenetree_dialog();
 	}
 }
@@ -3194,6 +3206,27 @@ void EditorPropertyResource::_viewport_selected(const NodePath &p_path) {
 	update_property();
 }
 
+EditorInspector *EditorPropertyResource::_get_parent_inspector() {
+	Node *parent = get_parent();
+	while (parent) {
+		EditorInspector *inspector = Object::cast_to<EditorInspector>(parent);
+		if (inspector) {
+			return inspector;
+		}
+		parent = parent->get_parent();
+	}
+	return nullptr;
+}
+
+void EditorPropertyResource::_scene_tree_visibility_changed() {
+	if (!scene_tree->is_visible()) {
+		EditorInspector *parent_inspector = _get_parent_inspector();
+		if (parent_inspector) {
+			parent_inspector->set_update_tree_paused(false);
+		}
+	}
+}
+
 void EditorPropertyResource::setup(Object *p_object, const String &p_path, const String &p_base_type) {
 	if (resource_picker) {
 		memdelete(resource_picker);

editor/editor_properties.h

@@ -677,6 +677,9 @@ class EditorPropertyResource : public EditorProperty {
 
 	void _viewport_selected(const NodePath &p_path);
 
+	EditorInspector *_get_parent_inspector();
+	void _scene_tree_visibility_changed();
+
 	void _sub_inspector_property_keyed(const String &p_property, const Variant &p_value, bool p_advance);
 	void _sub_inspector_resource_selected(const Ref<Resource> &p_resource, const String &p_property);
 	void _sub_inspector_object_id_selected(int p_id);

scene/main/viewport.cpp

@@ -167,7 +167,10 @@ Ref<Image> ViewportTexture::get_image() const {
 }
 
 void ViewportTexture::_err_print_viewport_not_set() const {
-	if (!vp_pending && !vp_changed) {
+	// Removing this error while in the editor to prevent printing this error
+	// while creating the new ViewportTexture. When creating a new ViewportTexture in the editor,
+	// it's normal that the vp is not initialized.
+	if (!vp_pending && !vp_changed && !Engine::get_singleton()->is_editor_hint()) {
 		ERR_PRINT("Viewport Texture must be set to use it.");
 	}
 }